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Advances and development of
wind–solar hybrid renewable
energy technologies for energy
transition and sustainable future
in India
J Charles Rajesh Kumar
1
and MA Majid
1
Abstract
While solar power projects are built on a continuous ground, wind power projects require scat-
tered land, raising transmission costs and increasing the risk of land-related complications.
Wind–solar hybrid (WSH) projects have been proposed to address these issues and accelerate
installation. WSH power projects will create a well-defined area with sufficient infrastructure,
including evacuation facilities, where the project’s risks can be reduced. The extensive coastline
of India is endowed with high wind flow speed and plentiful solar power resources, creating an
ideal environment for WSH projects to prosper while simultaneously improving grid stability and
reliability. WSH plants guarantee higher transmission efficiency and cost-effectiveness than their
stand-alone counterparts. As of 30.11.2021, 3.75 GW of WSH projects have been granted, with
0.148 GW of operational capacity and 1.7 GW of WSH projects in various bidding phases. In
this paper, we discussed state-wise WSH potential, the key players in the WSH project, the
National WSH, and the State WSH policy and amendments. Also, the WSH project’sphysicalpro-
gress and commercial details are covered. A feasibility study of the WSH plant is performed, and the
primary design strategy for deploying WSH power facilities in India is discussed. It covers every step
of this process, from design technique to choosing and evaluating potential locations for such hybrid
projects, optimally placing wind turbines and solar panels, overall capacity mix for hybrid plants, and
ultimately power evacuation optimization. Additionally, a brief study of the savings from these hybrid
plants and the environmental, social, and governance standards which are necessary to implement
these projects are provided. The potential challenges connected with WSH technologies are exam-
ined in depth, and potential solutions and mitigations for the challenges are provided. Designing a
WSH for small-scale irrigation is provided along with the size and choice of wind and solar systems.
1
Department of Electrical and Computer Engineering, College of Engineering, Effat University, Jeddah, Saudi Arabia
Corresponding author:
J Charles Rajesh Kumar, Department of Electrical and Computer Engineering, College of Engineering, Effat University,
Saudi Arabia.
Email: charlesece@yahoo.com
Original Article
Energy & Environment
1–49
© The Author(s) 2023
Article reuse guidelines:
sagepub.com/journals-permissions
DOI: 10.1177/0958305X231152481
journals.sagepub.com/home/eae
Degradation of PV systems and carbon savings are included, along with some policy measures to
boost the proportion of WSH in the entire power mix. In India, the development of large-scale
WSH projects is still in its early stages, and more research is required to explore technical, com-
mercial, and policy elements that influence project design. The policy suggestions for improvement
of the WSH project are provided. The WSH project developers, potential investors, stakeholders,
innovators, policymakers, manufacturers, designers, and researchers will benefit from the recom-
mendations based on the review’sfindings.
Keywords
Wind–solar hybrid (WSH), policies, tariff, feasibility, risk and challenges
Introduction
Coal remains the most widely used fuel for electricity generation worldwide, so air pollution levels
worldwide have increased.
1
As a result, air quality and climate changes are impacted, resulting in
global warming.
2
The increase in climate change challenges and environmental impacts has
prompted several nations worldwide to minimize their carbon footprint for energy production
and switch to cleaner and greener technologies. Furthermore, countries worldwide have promised
to reduce their reliance on fossil fuels such as diesel, lignite, coal, and gas for electricity generation.
For example, India pledged that by 2022, it would install 175 GW of renewable energy through
non-fossil sources such as hydro, solar, wind, biomass/cogeneration, waste-to-energy, and small
hydro in its power sector. The installation includes 5 GW of small hydropower, 10 GW of bio-
power, 60 GW of wind, and 100 GW of solar power.
3
As of March 31, 2022, 163.388 GW of
renewable energy had been installed, compared to a goal of 175 GW. Also, as of November 30,
2022, 166.362 GW of renewable energy (large hydro, small hydro, wind, bio, and solar) and
236.018 GW of fossil fuel (coal, lignite, gas, and diesel) had been installed. Total installed capacity,
including fossil, non-fossil, and nuclear, is 409.161 GW. Interestingly, India set an ambitious target
to increase renewables installation capacity to 450 GW by 2030.
4
It is worth noting that India is the
third-largest emitter of green-house-gases next to China and the USA.
5
The renewable energy
sector is critical as it may help combat climate change and cut fossil fuel usage.
While solar power projects are built on a continuous ground, wind power projects require scat-
tered land, raising transmission costs and increasing the risk of land-related complications. Wind–
solar hybrid (WSH) projects have been proposed to address these issues and accelerate installation.
WSH power projects will create a well-defined area with sufficient infrastructure, including evacu-
ation facilities, where the project’s risks can be reduced. A typical problem is the uncertain electrical
energy output of stand-alone solar and wind energy systems, and climate and weather variations
impact power output. However, the WSH-generating system can help mitigate some of the
issues.
6
The extensive coastline of India is endowed with high wind flow speed and plentiful
solar power resources, creating an ideal environment for WSH projects to prosper while simultan-
eously improving grid stability and reliability. WSH plants guarantee higher transmission efficiency
and cost-effectiveness than their stand-alone counterparts.
7
A hybrid technique that integrates solar
and wind energy enhances the capacity utilization factor (CUF) and assures improved grid resili-
ence and stability. The Central Electricity Regulatory Commission (CERC) of India has estimated
that when the annual mean wind power density (WPD) is between 220 and 275 W/m
2
, the value of
CUF is 24% and 22% up to 220 W/m
2
. Similarly, when annual WPD is between 331 and 440 W/
m
2
, the CUF value is 33% and 35% for values higher than 440 W/m
2
. WSH plants have a CUF
2Energy & Environment 0(0)
between 35% and 50%, significantly higher than wind or solar power alone.
8
Gujarat (824 MW),
Rajasthan (442.25 MW), Maharashtra (34), Andhra Pradesh (23.5 MW), Tamil Nadu
(17.06 MW), and Karnataka (14 MW) have the highest solar energy potential in India.
9
Gujarat
has the highest wind energy potential at 50 m in India (10609 MW), Tamil Nadu (5374 MW),
Karnataka (8591 MW), Maharashtra (5439 MW) and Rajasthan (5005 MW), Andhra Pradesh
(5394 MW), and Jammu & Kashmir (5311 MW).
10
Integrating solar energy and wind energy
will result in a stable form of supply. Solar and wind-rich sites can be identified with appropriate
due diligence to effectively develop hybrid plants to enhance grid stability, regulate voltage,
decrease electric supply intermittency, and optimize infrastructure and land use. The Indian govern-
ment should step up to meet the renewable power target, and WSH facilities are the ideal method to
accomplish it. Power producers can utilize land and electrical transmission infrastructure with WSH
projects. WSH plant development will help expand renewable power in India’s energy mix, assure
grid stability, and promote the most efficient use of land and other resources to create a cost-
competitive sector. Wind and solar power are intermittent energy generators that provide power
at different intervals and seasons. Solar energy is considerably productive during the day, but
wind energy is only effective at night.
11
The combined form of solar and wind energy supplies elim-
inates mutual intermittences due to their unfavorable nature, improving the system’s reliability.
12,13
The overall fluctuation of the output generated can be mitigated by integrating wind and solar,
which are complementary, and the combined production is undoubtedly more amenable to grid
integration.
14
Hybrid energy systems have gained much attention since they can be utilized in
remote locations where grid power is inaccessible.
15
WSH designs are utilized in wastewater treat-
ment,
16
rural electrification, and water-pumping irrigation systems.
17
For instance, one of the larger
islands in the delta, Sagar Island, experiences regular power outages and has a very unreliable grid
electricity supply.
18
Long-term studies revealed that Sagar Island has a very high potential for wind
energy. The viability of establishing a grid-connected wind power facility in Sagar Island is inves-
tigated to offer a dependable and uninterrupted power supply. The wind-generating facility will
lessen the load on the grid’s power supply. A grid-connected solar–wind hybrid plant for a
remote island (Sagar Island, the world’s largest delta) is developed with a reduction in levelized
tariff.
19
Most island residents will have access to energy if the cost is reduced. As a result, the
per unit power consumption and, subsequently, the human development index will rise.
The suggested power plant will lessen CO
2
emissions by 1894.08 t yearly, which will positively
impact the environment. Throughout its lifespan, it will also conserve 587.39 t of coal. Because
they produce no hazardous emissions, solar–wind hybrid systems have become crucial for supply-
ing energy to membrane desalination systems.
20
Reverse osmosis (RO) desalination, which can
produce fresh water, is powered by hybrid plants. Alagar et al.
21
discussed using hybrid energy
systems in India. In this study, hybrid energy resources are created by combining solar photovol-
taic, wind energy, diesel generators, and battery. The home building’s electrical utility is considered
a load when using the HOMER software application to examine the hybrid energy sources.
Bhattacharjee et al.
22
discussed using hybrid systems in India, which were designed for four
regions based on local climatic data. The function of hybrid power systems based on renewable
energy in addressing climate change is discussed. The hybrid energy production cost and installa-
tion cost are also discussed. The levelized cost of the proposed system is 0.688 $/kWh. Khan et al.
23
performed a feasibility study on a solar-wind hybrid energy system in remote regions of India’s
north. It is anticipated that hybrid systems operating in independent and grid-connected modes
will be able to meet both the current and future requirements for electric power. Das et al.
24
com-
prehensively reviewed a hybrid system using wind and solar energies. The policies, barriers, and
recommendations for the Indian hybrid system are discussed. Prakash et al.
25
proposed an
Charles Rajesh Kumar et al. 3
economic and technological assessment of a standalone hybrid system in Kalpeni Island in India
using HOMER computational tool. Sensitivity analysis is carried out to understand the increase
in load, diesel price increase, battery minimum state of charge (SOC), increase in solar photovoltaic
system (PVS) derating, increase in PV cell temperatures, and change in inverter and rectifier effi-
ciencies. The levelized cost of the proposed system is 0.222 $/kWh.
In June 2016, the Ministry of New and Renewable Energy (MNRE) issued a draft WSH policy.
The policy intends to accomplish a combined WSH capacity of 10 GW by 2022. It intends to stimu-
late technological advances, techniques, and solutions, including mixed wind and solar plant opera-
tions.
26
To facilitate the expansion of WSH projects in the country, the MNRE announced the WSH
Policy on May 14, 2018.
27
The WSH Policy is drafted to create an essential structure for developing
massive grid-connected WSH systems to maximize transmission infrastructure and land use, reduce
renewable energy supply variability, and improve grid stability. Gujarat, Rajasthan, and Andhra
Pradesh have developed their WSH policies according to the national WSH policy.
28
The SECI
and many state governments continue to offer incentives to encourage the construction of WSH
facilities. SECI has taken the initiative by announcing major tenders regularly to scale-up market
expansion. As of November 30, 2021, 3.75 GW of WSH projects has been granted, with
0.148 GW of operational capacity. 1.7 GW of WSH projects is in various bidding phases. It is esti-
mated that WSH capacity to accomplish 11.7 GW by 2023. From 2020 to 2023, the
compound-annual-growth rate (CAGR) is anticipated to be 223%.
29
WSH is expected to reduce
capital costs by 5%–7% compared to stand-alone wind and solar assets, increasing developer
returns. The WSH projects would result in capital cost reductions because of the improved utiliza-
tion of shared infrastructure such as evacuation infrastructure, access roads, and land. WSH, on the
other hand, will take a few more years to take off due to many technological obstacles in integrating
wind and solar systems. Choosing sites appropriate for wind and solar energy generation,
30
the
availability of sufficient transmission infrastructure,
31
technical challenges in combining the two-
generation sources, and the techniques to handle the generation from solar and wind resources
would be hurdles for WSH projects. The underlying barriers must be identified and effectively
managed to keep the market growing. Lower tariffs, policy uncertainties, land limitations, integra-
tion hurdles, system sizing,
32
and inadequate expertise are all difficulties faced by the WSH indus-
try developers. Even if the announced national WSH policy is intended to increase renewable
energy generation, a sufficient number of evacuation networks
13
will be necessary. The supply
of electrical evacuation through the same infrastructure, in particular, has been positively received
by developers. It is unclear whether the grids can handle the additional evacuation, as distribution
companies have previously denied such licenses due to grid instability. During April and June each
year, the Indian state of Tamil Nadu can harness the highest wind speeds of up to 25 m/s.
On the other hand, the grid is not intended to handle the additional generation, so they cannot tap
the surplus energy. While the WSH policy would help meet the renewable power sustainability
goals, it is critical to concentrate on grid capabilities.WSH projects will necessitate effective
design
33
and planning capability to modify existing units and allocate new projects due to land
acquisition challenges. Furthermore, the areas of Gujarat, Andhra Pradesh, Maharashtra, and
Tamil Nadu, where both wind and solar power sources are readily available and financially
viable, are primarily limited. This could be a stumbling block for India’s WSH capacity expansion.
Despite the policy’s progressive nature, challenges with synchronized working with grid voltage
and frequency
34
and hybrid inverter behavior remain significant. The government’s focus on sup-
porting the adoption of innovative technology and improvements in the inverter space
35
would be
included in the systems to address this problem. The inclusion of battery storage can reduce power
fluctuation from the hybrid plant, allowing for increased power output from the sanctioned or
4Energy & Environment 0(0)
bidden capacity at delivery locations and assuring stable power for the period stipulated.
Incorporating high percentages of wind and solar renewables into energy systems requires
battery storage devices.
36
Most WSH systems use power stored in batteries to provide power
when neither the solar nor the wind systems produce energy. Incorporating battery storage is cer-
tainly not a viable solution because it dramatically raises project expenses and, as a result, tariffs.
On the other hand, the lowering trend in battery pricing will make the WSH projects viable in a few
years and deliver more consistent electricity. Compared to a standalone wind or solar facility, a
WSH plant requires less storage capacity to stabilize the grid, lowering the cost of power.
The global WSH systems market was worth USD 925.2 million in 2019 and is predicted to grow
at a CAGR of 7.2% between 2020 and 2027. The market is expected to be driven by rising demand
for renewable energy sources and increased government spending to stimulate the expansion of the
solar and wind power sectors. North America (USA, Mexico, and Canada), South America
(Argentina, Brazil, and Columbia), Europe (Germany, France, Spain, UK, and Italy), Asia
Pacific (China, Japan, Australia, Korea, and India), the Middle East and Africa (UAE, Saudi
Arabia, Nigeria, South Africa, and Egypt) are the most important countries in the market. The
Asia Pacific market is predicted to lead the WSH market in income. Rapid urbanization and
increased investments in implementing sustainable technologies in emerging nations like China
and India are anticipated to fuel the targeted market’s expansion. Because of government measures
to promote renewable power and the ample supply of solar and wind energy, the European market is
likely to account for a considerable part of income in the near years. The top global companies
involved in the WSH market are Alpha windmills, ReGEN Powertech, Supernova technologies
private limited (Ltd), Grupo Dragon, Zenith solar systems, Polar power, Unitron energy systems
private Ltd, UGE International, Alternate Energy Company, Gamesa renewable energy, Unitron
energy systems, General windmills, Windstream technologies, new windsoleil, Shuangdeng
group, etc. There are only a handful of WSH plants in India right now. This approach can only sig-
nificantly help these plants take off if there are enough fiscal incentives
37
and favorable regulatory
measures. The policy must foster technological advances and strategies for more seamless wind and
solar plant integration. The policy does not provide a clear structure for transforming current wind
or solar facilities into hybrid facilities instead of relying primarily on government procurement from
new projects, which is a disadvantage. However, these concerns may be solved by implementing
more consistent policies and standards as the sector evolves. In this paper, national and state
policy and regulations advancements, tender activities, significant market participants, tariff ana-
lyses, feasibility studies, and the potential challenges connected with WSH technologies are exam-
ined in depth. The numerous challenges faced by the WSH sector are identified, and solutions and
mitigations are provided, along with policy suggestions for improvement. The WSH project devel-
opers, potential investors, stakeholders, innovators, policymakers, manufacturers, designers, and
researchers will be benefitted from the recommendations based on the review’sfindings.
Indian WSH sector
India’s social and economic development is dependent on energy. Indigenous power sources must
be utilized to their full potential to reduce reliance on imported fuels while also addressing eco-
nomic, social, and ecological limitations. This prompted research, development, and investments
in the renewable energy industry to find innovative solutions to meet energy requirements while
reducing reliance on fossil fuels. Wind and solar power are increasingly popular in India
because of their surplus, availability, and convenience of harnessing for electrical power generation.
SECI serves as the nodal agency for the scheme’s implementation and holds the bidding process.
Charles Rajesh Kumar et al. 5
The minimal tariff for a WSH project was Indian rupees (INR) 2.67 per unit in 2018. With the
National Institute of Wind Energy (NIWE), MNRE, and the Technical University of Denmark’s
support, WSH projects are identified. The potential for more than 200 watts per square meter of
WPD with negligible seasonal trend variation has been recognized at 24 sites scattered across
India’s windy states.
38
The highest solar energy generation potential in windy areas has been docu-
mented. As a result, combining various renewable sources through hybrid power systems is bene-
ficial in lowering power requirements and ensuring a steady supply of renewable power to the grid.
In India, renewable hybrid power plants could be a real game-changer. As of 30.11.2022, the total
capacity installed of 41.895 GW of wind and 61.966 GW of solar energy. A hybrid system inte-
grates solar and winds energy with another generation or storage resource. Solar irradiance is
maximum between 11 a.m. and 3 p.m. in India, while wind output is maximum late at night and
early in the morning. Peak energy demand occurs between 6 p.m. and 9 p.m. when neither wind
nor solar can meet it. The WSH system generates round-the-clock renewable energy according
to varying daily demand levels by storing power during surplus renewable production hours.
During peak demand hours, it is delivered into the grid. Batteries,
39
mechanical storage via fly-
wheels,
40
and pumped hydro are all options for storage. The comparison of standalone solar, stan-
dalone wind, and WSH plants are provided in Table 1. When substantial wind speeds and high solar
radiation are present, renewable energy sources like solar and wind provide sustainable, econom-
ically viable alternatives to conventional energy production. The power produced by the hybrid
system is higher than the individual systems. When solar and wind resources are used together
to generate electricity, their daily and seasonal changes complement one another. Depending on
the local conditions, combining wind and solar renewable energy sources could increase system
reliability and reduce system costs. CUF percentage is higher for hybrid systems. Because wind
and solar use the same equipment and systems at the same site, it is more affordable and simpler
to maintain. It reduces project costs due to optimizing land use, power evacuation, infrastructure
operation, components, and people.
The state-wise WSH potential in India is indicated in Table 2. According to estimates, India has a
total solar-wind hybrid capacity of up to 10,300 GW. Shakti Sustainable Energy Foundation pre-
pared the assessment report (SSEF), Wind Force Management Services (WFMS), and Centre for
Study of Science, Technology, and Policy (CSTEP) in 2016. The report estimates that there are
103,082 square kilometers of usable land. The hybrid-capable wind potential is estimated at 585
GW, and the hybrid-capable solar potential is estimated at 11,380 GW. The solar potential has
been computed for regions with a worldwide horizontal irradiance of more than 5.7 kWh per
square meter. The wind potential has been computed for regions with wind speeds greater than
6 m/s at 120 m hub height.
WSH power generation sites in India based on NIWE
The presence of renewable energy resources on a given site is a critical aspect of developing hybrid
projects. Solar and wind energy are plentiful in many places in India, paving the potential for their
effective integration. Summer has a lower wind speed, but the sun shines most and lasts the longest.
During the monsoon season, the wind is mighty, and there is less sunshine due to cloud cover. WSH
systems can supply consistent energy to meet the energy requirements because the wind and solar
systems operate at different periods of the day and year. Most hybrid approaches use power stored
in batteries to supply energy when neither the solar nor the wind systems produce it. If the power
goes low, a traditional fuel-powered engine generator can be fitted to recharge the batteries, ensur-
ing that constant power is available to fulfill load demands from time-to-time. The solar data
6Energy & Environment 0(0)
utilized in this review comes from the solar radiation resource assessment (SRRA) atlas.
41
It is
based on 115 sites in the SRRA network and data between 1999 and 2014 of satellite-derived
maps and data utilizing the regional adjustment and verification method. Sensors installed at
various altitude levels were used to collect data on wind speed (100, 80, 50, 10, and 5 m). The
wind velocity data used in this investigation came from a height sensor set at 100 m. The annual-
energy production was calculated using wind velocity information and a normalized 2-MW power
curve. Possible solar energy generation at the windy sites is recorded, shown in Table 3.
Around 24 states are chosen with high wind potential based on installed met-masts. It is
observed that the highest solar energy produced at the windy sites are Kalimandayam,
Mustigeri, Chadmal, Machenahalli, Palayam, Kompalli, Pandhro, Devareddypalli, Motibaru,
Haikal, Bassi, Gara, Suigam, Taralkatti, Kuran, Nirana, Ganesh Goshla, and Dag. The lowest
power generation sites are Melamandai, Jamgodrani Hills, Akkanayakanpatti, Gaga, Veralimalai,
Kondurpalem, and Sunkisala. Solar helps compensate for the decline in wind generation wherever
Table 1. Comparing standalone solar, standalone wind, and WSH plants.
S. No. Parameters Standalone wind plants Standalone solar plants WSH plants
1Definition Power stations rely
entirely on the wind
to generate
electricity/harness
energy.
Power stations rely
entirely on solar to
generate electricity/
harness energy.
Power stations rely entirely
on wind and solar to
generate electricity. Solar
and wind energy facilities
are combined to
maximize output.
2 Power
produced
The energy generation
is high during the
early morning and
late-night hours and
rainy seasons.
When the sky is clear
during the day, the
temperature is high.
From 11 a.m. until 4
p.m., the most
increased generation
occurs.
Wind and solar are
complementary. Thus,
they work around the
clock. It lowers
day-to-day and seasonal
changes.
3 Capacity
utilization of
transmission
It is still underutilized. It is still underutilized. It is utilized efficiently.
4 Power
requirement
met
With fluctuating wind
patterns and banking
term constraints, it
can meet up to 50%
of power necessities.
With the time of day and
adjustment of
wheeling constraints,
it can fulfill 40%–50%
of power
requirements.
Even with time-of-day-based
power limits, it can
provide 75–80% of power
requirements.
5 CUF (%) 20%–26% 16%–20% 35%–50%
6 RPO Only the non-solar
RPO has been met.
Only the solar RPO has
been met.
RPO accomplishments are
more straightforward
because it includes both
non-solar and solar RPO.
7 Cost of the
project
(million per
MW)
INR 55–65 INR 35–40 INR 46–48
Charles Rajesh Kumar et al. 7
the wind is a downtrend. As a result, combining various renewable sources through hybrid energy
systems is beneficial in lowering power requirements and ensuring a steady supply of renewable
energy to the grid. The Indian government has designated approximately 10,789 square kilometers
of land in seven states (Telangana, Andhra Pradesh, Karnataka, Tamil Nadu, Gujarat, Rajasthan,
and Madhya Pradesh) to develop wind parks or WSH parks with a combined capacity of about
53.945 GW. Every park has a capacity of at least 0.5 GW. However, the government noted that
this is merely an indicative listing, and states may choose to build solar and wind parks in other
regions if possible. According to the proposal, parks with a smaller capacity may be constructed
based on resource and site availability, but each park’s capacity must not be less than 50 MW.
National WSH policy—2018
The MNRE drafted the national WSH policy on October 6, 2016.
42
The goal is to create an essential
structure for developing extensive grid-connected WSH systems for the most productive and effect-
ive use of land and transmission infrastructure, minimizing renewable energy production
Table 2. The state-wise WSH potential in India.
S. No.
Name of the
state
Area
(square km)
Potential of
solar (GW)
The hybrid-capable potential
of wind at 120 m hub height
(GW)
Potential of hybrid
energy (WSH)
(GW)
1 Goa 36 4.0 0.2 3605
2 Gujarat 27,531 3087 157 2794
3 Andhra Pradesh 20,000 220 112 1987
4 Maharashtra 18,612 2054 106 1860
5 Rajasthan 15,230 1705 86 1545
6 Karnataka 8000 915 45 828
7 Jammu and
Kashmir
6361 629 36 570
8 Tamil Nadu 3331 380 19 344
9 Orissa 2653 275 15 249.5
10 Uttaranchal 973 94 5.5 85.5
11 Chhattisgarh 102 11 0.6 9.9
12 Kerala 80 9 0.5 7.8
13 Andaman and
Nicobar
60 6.1 0.4 5.5
14 Dadra and
Nagar Haveli
42 4.5 0.2 4.1
15 Madhya Pradesh 22 2.5 0.1 2.1
16 Puducherry 19 2 0.1 2
17 Daman and Diu 13 1.5 0 1.3
18 Himachal
Pradesh
6 0.5 0 0.5
19 Sikkim 6 0.6 0 0.5
20 Arunachal
Pradesh
2 0.2 0.2 0.2
21 West Bengal 3 0.3 0 0.2
∗∗∗ Total 103,082 11,380 585 10,300
8Energy & Environment 0(0)
fluctuations and improving grid stability that strengthens India’s energy security. The National
WSH policy was adopted on 14.05.2018 by the MNRE.
43
The policy aims to promote technological
advances, techniques, and workarounds that integrate solar and wind plants. The MNRE issued an
amendment on August 13, 2018 and clarified that the energy storage of WSH is not only batteries.
Other forms of the appropriate storage capacity may also be incorporated, such as compressed air,
pumped hydro, flywheel, etc. can be used to smoothen the WSH power further.
44
On June 26, 2018,
Gujarat issued its WSH policy.
45
On January 3, 2019, Andhra Pradesh came out with a viable
policy on harnessing WSH energy, and on 18.12.2019, Rajasthan’s WSH policy became
active.
46
Karnataka and Kerala issued their draft version of WSH policies, and more states are
anticipated to follow the line. With considerable renewable power capacity additions and a national
WSH policy targeted at better resource utilization, this policy is expected to create a new route for
renewable energy availability at competitive pricing and decreased fluctuations. A summary and the
highlights of the national WSH policy are provided below.
(a) Unless the government withdraws, modifies, or replaces this policy, it will continue. As and
when necessary, the government will review this policy.
(b) Wind turbine generators and solar PV systems must be appropriately designed to run at a WSH
facility’s same grid connection point. Multiple techniques can be utilized for integrating wind
and solar depending on their size
47
and the technology involved.
Table 3. WSH sites and yearly wind, solar, and WSH energy generation.
S. No.
Name of the
state in India Site name
Yearly wind power
generation per MW
(kWh)
Yearly solar
power generation
per MW (kWh)
Yearly WSH power
generation per MW
(kWh)
1 Tamil Nadu Kalimandayam 2,263,184.746 1,488,038 3,751,222.746
2 Karungal/Palayam 2,649,320 1,478,350 4,127,669.714
3 Melamandai 2,482,315 1,452,490 3,934,804.912
4 Akkanayakanpatti 2,867,774 1,430,690 4,298,464
5 Viralimalai 1,993,187 1,358,837 3,352,024
6 Andhra
Pradesh
Kondurpalem 2,042,049 1,425,975 3,468,024
7 Devareddypalli 2,690,845 1,551,707 4,242,552
8 Telangana Kompalli 2,678,020 1,509,371 4,187,391
9 Sunkisala 1,970,826.413 1,404,415 3,375,241.413
10 Chadmal 2,595,608 1,472,125 4,067,733
11 Karnataka Mustigeri 1,857,387 1,543,907 3,401,294
12 Taralkatti 2,849,633 1,525,679 4,375,312
13 Machenahalli 1,878,793.982 1,540,516 3,419,309.982
14 Haikal 2,386,807 1,597,156 3,983,963
15 Gujarat Suigam 2,235,199 1,531,701 3,766,900
16 Kuran 2,335,965 1,485,120 3,821,085
17 Pandhro 2,916,398 1,503,197 4,419,595
18 Motibaru 2,416,565 1,489,402 3,905,967
19 Gaga 2,727,095 1,546,925 4,274,020
20 Madhya
Pradesh
Ganesh Goshla 2,522,452 1,523,679 4,046,131
21 Jamgodrani Hills 2,685,247 1,528,843 4,214,090
22 Rajasthan Dag 2,438,858 1,522,642 3,961,500
23 Gara 1,964,369.881 1,547,663 3,512,032.881
24 Bassi 1,930,770 1,575,382 3,506,152
Charles Rajesh Kumar et al. 9
(c) When high-speed wind turbines are attached to the utility grid utilizing an induction gener-
ator,
48
integration is possible on the high-tension side at the alternating current output bus.
In the case of variable-speed wind turbines that use inverters to link to the grid, the solar
and wind systems can be coupled to the AC–DC–AC converter’s
49
intermediate DC bus.
(d) In areas with a low or moderate wind power density (WPD), compared to the solar energy
system installed, the wind energy component’s size installed must be much smaller and
vice versa.
(e) In a WSH plant, the power rating capacity of wind must be not less than 25% of the power
rating capacity of solar and vice versa.
(f) The policy allows alternating current integration of the WSH system. AC outputs from wind
and solar are connected utilizing a high or low-tension line. If the step-up transformers in the
wind and solar systems are dissimilar, the output power from both systems is linked to the
same AC bus. In addition, the system’s output power would need to be regulated, necessitating
proper control equipment use.
50
(g) The policy allows direct current integration of the WSH system. Wind and solar systems’DC
outputs are supplied into the same DC bus. A suitable inverter is employed for transforming
into AC power from the total DC energy output.
(h) The policy’s goal is to promote the creation of new WSH initiatives and the conversion of
current solar and wind facilities into hybrids. It allows for hybridizing current wind or solar
projects with more transmission capacity than sanctioned, depending on the margin available
in existing transmission capacity.
(i) Suppose already approved transmission access or the existing wind or solar plants utilize con-
nectivity. In that case, the corresponding transmission entity will not levy fees for transmission
capacity or supplementary connection. Transmission rates apply if increased transmission cap-
acity or access is allowed following current regulations
(j) Suppose capacity margins are present at the receiving transmission sub-station of the transmis-
sion company at which the existing wind or solar projects are connected. In that case, add-
itional transmission capacity or access may be authorized subject to technical feasibility.
However, charges may be imposed for other transmission access as per current regulations.
(k) Wind and solar power sent to the grid by WSH projects with AC integration will be calculated
by apportioning the reading of the main meter reading, which is mounted to the receiving
station. It would relate to the readings of availability-based tariff (ABT) meters mounted on
the high tension (HT) and low tension (LT) lines of the WSH power plant.
(l) Wind and solar power sent to the grid by WSH projects with DC integration will be calculated
by apportioning the main meter reading, which is mounted to the receiving station. However
applicable, it would relate to the readings of DC meters mounted on the DC output of the WSH
power plant. Only AC integration would be allowed until standards and rules for DC meters
and a mechanism for DC metering of WSH power projects are established.
(m) The power generated by WSH projects can be utilized for captive purposes and sold to a third
party via open access. It can be supplied to distribution companies at tariff rates set by the rele-
vant state electricity regulatory commission (SERC) or agreed to a tariff structure through a
competitive tendering procedure. It can be sold to distribution companies at an average
power purchase cost (APPC) to obtain renewable energy certificates (RECs). Central or
state governments may bid to hybridize existing projects linked to the interstate transmission
system (ISTS).
(n) Government bodies may issue tenders for hybridizing existing solar and wind installations,
with tariffs as the primary choosing criteria.
10 Energy & Environment 0(0)
(o) . The additional wind or solar power obtained from the WSH project can be used to meet the
solar or non-solar RPO requirements, as applicable.
(p) Storage devices integrated with WSH power projects enhance the consistency with which the
WSH plant produces output.
51
Boosting the WSH plant’s capacity will likely increase produc-
tion more than the sanctioned load. It ensures that power is available at all times. Factors such
as minimal uninterrupted power supplies for the entire day or portion of the day, degree of
output inconsistency, and the tariff will influence the tender procedure for a WSH power
plant with storage devices.
(q) The Central Electricity Authority (CEA) and the Central Electricity Regulation Commission
(CERC) will devise the essential standards and rules for WSH plants, such as the REC mech-
anism, grant of transmission line sharing and connection, technique, and criteria for metering,
and regulations on scheduling and forecasting.
(r) To correctly manage wind turbines, solar panels, and the system balance equipment in grid-
connected systems, each developer must satisfy MNRE’s technological procedures.
(s) Numerous government policies and plans will accelerate the expansion of WSH projects.
WSH system developers can also take advantage of all the fiscal and financial benefits avail-
able for WSH projects, similar to standalone solar and wind energy projects.
(t) The government will also contribute to technological advances in WSH energy production
systems and establish WSH system standards.
The MNRE drafted the National WSH policy on October 6, 2016. The MNRE issued the National
WSH policy on May 14, 2018, and amendments to the policy (storage and battery) were issued on
August 13, 2018. The guidelines for a tariff-based competitive bidding process for power procure-
ment from grid-connected WSH projects were issued by the MNRE on October 14, 2020. The
Hybrid project commissioning timeline is 18 months. The Amendment in guidelines for tariff-based
competitive bidding process for power procurement from grid-connected WSH projects was issued
by the MNRE on July 23, 2021. It stated that the projects must be completed by the scheduled com-
missioning date (SCD), 24 months after the Power Purchase Agreement/Power Sale Agreement
was signed. If commissioning takes longer than expected, there should be penalties for the
hybrid power generator. (1) For commissioning delays of up to 6 months from the SCD, the per-
formance bank guarantee will be cashed daily and in proportion to the capacity that was not
commissioned. (2) A generator event of default will be considered if the commissioning delay
extends 6 months from SCD, and the contracted capacity will be reduced to the project capacity
that has been commissioned up to SCD plus 6 months. The PPA for the balance capacity will be
terminated. (3) The criteria further state that the project will only be considered for commissioning
or partial commissioning once the generator provides proof of land ownership. (4) The guidelines
further state that it is presumptive that the relevant body will approve tariffs within 60 days after
application. If the adoption of such tariffs is delayed, the SCD will also be extended in accordance.
The comparison of WSH policies of the state and central governments
Table 4 compares the WSH policies of India’s State and Central governments. Gujarat, Rajasthan,
and Andhra Pradesh are among the states that have developed their respective WSH policies.
Table 5 compares India’s State and Central governments’WSH policies (Restrictions and
Waivers). Kerala and Karnataka created the WSH policies of their respective states, and a few
other states are in the law to develop the draft.
Charles Rajesh Kumar et al. 11
Table 4. The comparison of WSH policies of India’s state and central governments.
S. No. Parameter MNRE Gujarat Andhra Pradesh Rajasthan
1 Date of
publication
May-2018 June-2018 December-2019 December-2019
2 Targeting –– 3.5 GW by 2018–23 3.5 GW by 2024–
25
3 Operative
timeframe
–2018–23 2018–23 –
4Definition of
Hybrid
25:75 –25:75 25:75
5 Capacity
utilization
factor
–– For every 1 MW of
WSH systems, a
minimum of 40%
CUF must be
attained.
–
6Defined Types –Currently in
development or
existing projects
(brownfield)
New WSH
projects
(greenfield)
–Current solar or
wind plants can
be hybridized.
(Type A)
New WSH
projects (Type B)
7 Configuration
and
Integration
–
8 Hybrid’s RPO
obligation
Non-solar
and solar
RPOs can
be
completed
separately.
Non-solar and
solar RPOs can
be completed
separately. (Type
A)
Common or
separate RPO is
permitted (Type B)
Non-solar and solar
RPOs can be
completed
separately.
Under this strategy,
distribution
companies must
buy energy equal
to 5% of their
RPO goals.
9 Banking –– Throughout all 12
months of the
year, 100%
banking is
permitted.
Banking fees are
adjusted in kind at
a rate of 5% of the
power supplied at
the time of drawl.
Banking fees will be
adjusted in kind
at a rate of 10%
of the power
supplied at the
time of drawl.
10 Second-hand
wind turbine
generators or
modules
(Restrictions)
–Not permitted ––
(continued)
12 Energy & Environment 0(0)
WSH project key players in India (2018–2022)
Table 6 shows the key players in WSH project development in India. The details are based on the
companies participating in the tariff-based competitive bidding procedure to procure energy from
grid-connected WSH projects as of July 2021.
52
In an office memorandum dated March 9, 2022, the
MNRE modified the parameters for competitive tendering based on tariffs for energy purchases
from grid-connected WSH installations.
WSH tender result and tariff in India (2018–2022)
On May 14, 2018, the MNRE released a national WSH policy,
24
and in December 2018, SECI held
the first bidding process for WSH with a capacity of 1200 MW. SBE Renewables Ten private
Limited won 450 MW at INR 2.67/kWh of electricity generated, while Mahoba Solar (UP)
private limited of Adani group won 390 MW at INR 2.69/kWh, is shown in Table 7. Only two
developers bid in the second auction, and there are no takers for the remaining 360 MW. There
were no bidders in the first auction of the sanctioned interstate transmission system (ISTS)
related WSH projects approved on May 25, 2018. It was reduced from 2500 to 1200 MW. A
hybrid system combines wind and solar by strategically placing wind turbines and solar panels.
As a result, SECI is eager to promote it because it decreases the need for land and transmission facil-
ities. On May 27, 2019, SECI held a bidding process for WSH with a capacity of 1200 MW. Adani
renewable energy park (Gujarat) limited won 600 MW at INR 2.69/kWh, while ReNew solar power
private limited did not win its 300 MW at INR 2.7/kWh. On October 18, 2019, SECI held a bidding
process for WSH with a capacity of 400 MW for RTC energy supply (RTC-I). ReNew solar power
private limited won 400 MW at INR 2.90/kWh, while Greenko energies private limited did not win
its 400 MW at INR 2.91/kWh, shown in Table 8. Similarly, HES infra private Ltd did not win its 50
Table 4. Continued.
S. No. Parameter MNRE Gujarat Andhra Pradesh Rajasthan
11 Load Sanctioned
(Restrictions)
–For the captive and
third-party
models, the
power
contracted shall
be 50% of the
sanctioned load
of the consumer
for solar and
wind,
respectively. On
the other hand,
the consumer
can set up a
WSH project to
meet RPO
without a
sanctioned load
limitation.
––
Charles Rajesh Kumar et al. 13
Table 5. The comparison of WSH policies (restrictions and waivers) of India’s state and central governments.
S. No. Parameter MNRE Gujarat Andhra Pradesh Rajasthan
1 Second-hand
wind turbine
generators
or modules
(restrictions)
–Not permitted ––
2 Load
sanctioned
(restrictions)
–For the captive
and third-party
models, the
power
contracted
shall be 50% of
the sanctioned
load of the
consumer for
solar and wind,
respectively.
On the other
hand, the
consumer can
set up a WSH
project to
meet RPO
without a
sanctioned
load limitation.
––
3 Cross-subsidy
surcharge—
CSS
(waivers)
–For third-party
sales, a
concession is
50%.
For captives,
there are no
fees waived.
A concession is
50% for
third-party sales
if the project is
built within the
state.
–
4 Extra
surcharges
(waivers)
–For third-party
sales, a
concession is
50%. For
captives, there
are no fees
waived.
––
5 Fees for
wheeling and
transmission
(waivers)
There will be no
additional
transmission or
connectivity
capacity
expenses for
existing
Captive
customers get
a 50% discount
on losses and
wheeling
charges.
For third-party
There is a 50%
reduction in
wheeling and
transmission
expenses for
new projects
A 50% concession is
available for
captive or
third-party sales
for the hybrid
project for the
first seven years
(continued)
14 Energy & Environment 0(0)
MW at INR 3.19/kWh. Ayana renewable power private limited was not shortlisted for the final
auction. On December 23, 2020, SECI held a bidding process for WSH with a capacity of 1200
MW. ABC renewable energy private limited won 380 MW at INR 2.41/unit, and Adani renewable
energy holding eight limited won 600 MW at INR 2.41/unit. AMP energy green private limited won
130 MW at INR 2.41/unit, and ACME solar holdings private limited won 300 MW at INR 2.42/
unit. Around five others participated in the auction and did not win. On April 15, 2021, SECI
held a bidding process for WSH with a capacity of 1200 MW.NTPC limited won 450 MW at
Table 5. Continued.
S. No. Parameter MNRE Gujarat Andhra Pradesh Rajasthan
facilities.
Furthermore,
extra
transmission
capacity will be
subject to
transmission
costs.
sales, there are
no waivers.
created within
the state.
after project
commissioning.
A 75%
concession is
available for
captive or
third-party sales
for the (hybrid +
storage) project
for the first seven
years after
project
commissioning.
6 Duty on
electricity
bills
(waivers)
–It is waived for
utilization
within the
state.
50% is waived for
utilization
within the state.
It is waived for
utilization within
the state.
7 Others
(waivers)
WSH plants will
be eligible for
all economic
and fiscal
incentives
presented to
solar and wind
energy
projects.
–Exemption from
the
requirement to
acquire a NOC/
consent from
the Andhra
Pradesh
pollution
control board.
Distributed
companies will
be considered
to have
purchased
unutilized
banked energy
at 75% of the
average power
procurement
cost (APPC).
–
Charles Rajesh Kumar et al. 15
Table 6. The key players in WSH project development in India.
S. No.
Name of the WSH project
developer
Participation in the
tender process scheme
Capacity allotted
(MW) 2018–2022
Cumulative capacity
allotted (MW) 2018–
2022
1 ReNew Solar Power
Private Limited
RTC –1, Tranche–II,
Tranche–III, ISTS–VII
400, NIL, NIL,600 1000
2 Greenko Energies Private
Limited
RTC –1, ISTS–VII NIL, 900 900
3 HES Infra Private Limited RTC–1, ISTS–VII NIL, NIL -
4 Ayana Renewable Power
Private Limited
RTC –1 NIL -
5 SBE Renewables Ten
Private Limited
Tranche–I 450 450
6 Mahoba Solar (UP) Private
Limited
Tranche–I 600 600
7 Adani Renewable Energy
Park (Gujarat) Limited
Tranche–II 600 600
8 ACME Solar Holdings
Private Limited
Tranche–III, Tranche–IV 300, NIL 300
9 AMP Energy Green
Private Limited
Tranche–III, Tranche–
IV, Tranche–V
130, NIL, 120 250
10 Adani Renewable Energy
Holding Eight Limited
Tranche–III 600 600
11 Azure Power India Pvt.
Ltd
Tranche–III, Tranche–IV NIL, 300 300
12 Energizent Power Private
Limited
Tranche–III, Tranche–IV NIL, NIL -
13 ABC Renewable Energy
Private Limited
Tranche–III, Tranche–IV 380, NIL 380
14 Green Infra Wind Energy
Limited
Tranche–III, Tranche–IV NIL, NIL -
15 NLC India Limited Tranche–III, Tranche–IV NIL, 150 150
16 Spring Ujjvala Energy
Private Limited
Tranche–III NIL -
17 TP Saurya Limited (Tata
Power)
Tranche–III, Tranche–
IV, Tranche–V
NIL, NIL, 600 600
18 Project Ten Renewable
Power Private Limited
Tranche–IV 450 450
19 ReNew Ushma Energy
Private Limited
Tranche–IV NIL -
20 NTPC Renewable energy
Limited
Tranche–IV, Tranche–V 450, 450 900
21 Hero Solar Energy Private
Limited
Tranche–IV NIL -
22 Anupavan Renewables
Pvt. Ltd
Tranche–IV NIL -
23 Avaada Energy Private
Limited
Tranche–IV NIL -
(continued)
16 Energy & Environment 0(0)
INR 2.34/unit, NLC India limited won 150 MW at INR 2.34/unit, and Project ten renewable power
private limited won 450 MW at INR 2.34/unit. Azure-power-India private limited won 300 MW at
INR 2.35/unit. Around 14 others participated in the auction and did not win. Request for selection
(RFS) of 1200 MW ISTS connected WSH projects (Tranche V) under tariff-based competitive
bidding was issued on October 22, 2021. Table 9 shows the tender details of companies other
than SECI involved in WSH project developments. The NTPC renewable energy limited requested
proposals in April 27, 2021 to develop 600 MW of ISTS-connected WSH projects throughout
India. The MSEDCL has invited a tender to procure WSH power to meet its renewable purchase
obligation (RPO) on September 6, 2019.
Tables 8–10 display the WSH auction details. The companies that participated in the auction and
won bids from various companies for SECI 1200 MW hybrid auction are listed. For instance, the
winners of the SECI auction held on May 24, 2022 to develop 1200 MW ISTS-connected WSH
projects (Tranche-VII) across India are NTPC Renewable energy Limited, Halvad Renewables
Private Limited, JSW Neo Energy Limited, and Torrent Power Limited. For instance, the
winners of the SECI auction held on May 5, 2022 to develop 1200 MW ISTS-connected WSH pro-
jects (Tranche-V) across India are Tata Power Saurya Limited, Amp Energy Green private limited,
and NTPC Renewable energy Limited. The tariff, determined at INR 2.53 per kWh, is 8.5% more
than the lowest bid, which was found at INR 2.34 per kWh at the last auction ((Tranche-IV) for the
WSH project by SECI. Each project required a minimum of 50 MW. The maximum project allot-
ment capacity for a bidder was 1200 MW. The WSH power projects were instructed to be con-
structed for connecting with the transmission network of the central transmission utility at the
operating voltage of 220 kV or above, per the tender documents that SECI floated in October
2021. It also stipulated that the energy project should contain solar and wind components. The
rated installed capacity of either solar or wind energy must be at least 33% of the project capacity
by the tender’s requirements. To guarantee that only high-quality systems are erected, only the wind
turbine models listed in the updated list of models and manufacturers provided by the MNRE were
permitted for deployment.
Table 6. Continued.
S. No.
Name of the WSH project
developer
Participation in the
tender process scheme
Capacity allotted
(MW) 2018–2022
Cumulative capacity
allotted (MW) 2018–
2022
24 Torrent Power Limited Tranche–IV NIL -
25 Adani Renewable Energy
Holding Nine Limited
Tranche–IV NIL -
26 Power Mech Projects
Limited
Tranche–IV NIL
27 Tunga Renewable Energy
Private Limited
Tranche–IV NIL
28 Eden Renewable Sully
Private Limited
Tranche–IV NIL
29 JSW solar limited Tranche–IX 1000
30 Vena energy vidyuth
private limited
Tranche–IX 160
40 Inox wind infrastructure
services limited
Tranche–IX NIL
Charles Rajesh Kumar et al. 17
Table 7. WSH capacity tendered in India (Tranche I, II, RTC-I, III, IV).
S. No. Name of the company
Capacity tendered
(MW)
Capacity
allotted
(MW)
Date of
issue
Annual CUF
(%)
Tariff (INR/
kWh)
Commissioning time
line
1 Mahoba Solar (UP) Private Limited—
Adani groups
1200 Tranche I
(SECI)
390 840 22.06.18 40 2.67 18 Months
2 SBE Renewables Ten Private Limited 450 2.69
3 Adani Renewable Energy Park (Gujarat)
Limited
1200 Tranche II
(SECI)
600 600 08.03.19 30 2.69 18 Months
4 Renew Solar Power Private Limited 400 (RTC-1)
(SECI)
400 400 18.10.19 80 (Annual)
70
(Monthly)
2.90 24 Months
5 AMP Energy Green Private Ltd 1200 Tranche III
(SECI)
130 1200 14.01.20 35 2.41 18 Months
6 Adani-Renewable-Energy Holding eight
ltd
600 2.41
7 ABC-Renewable-Energy Private Ltd 380 2.41
8 ACME Solar Holdings Private Limited 90 2.42
9 NTPC Limited 1200 Tranche IV
(SECI)
450 1200 15.04.21 30 2.34 18 Months
10 NLC India Limited 150 2.34
11 Project Ten Renewable Power Private Ltd 450 2.34
12 Azure-Power India Private ltd 150 2.35
18 Energy & Environment 0(0)
Table 8. WSH capacity tendered in India (Tranche V, VII, IX).
S. No. Name of the company Capacity tendered (MW)
Capacity
allotted
(MW) Date of issue
Annual
CUF (%)
Tariff
(INR/kWh)
Commissioning
time line
1 TP Saurya Limited 1200 ISTS V (SECI) 600 22.10.2021 33 2.53 18 Months
2 AMP Energy Green Private
Limited
120
3 NTPC Renewable Energy
Limited
450
4 Greenko Energies Private
Limited
1200 ISTS VII (SECI) 900 1200 01.08.19 35 2.88 (Off-peak)
6.12 (Peak)
24 Months
5 Renew Solar Power Private
Limited
300 2.88 (Off-peak)
6.85 (Peak)
6 NTPC Renewable Energy
Limited
1200 ISTS VII (SECI) 200 1100 24.5.2022 35 2.89 24 Months
Halvad Renewables Private
Limited
300 2.93
JSW Neo Energy Limited 300 2.94
Torrent Power Limited 300 2.94
7 Vena Energy Renewables 1200 Tranche IX (SECI—ISTS) 160 970 20.03.20 30 2.99 18 Months
8 JSW Solar 810 3.00
Charles Rajesh Kumar et al. 19
WSH project physical progress and commercial details
Increased electricity can be generated by combining wind and solar energies. WSH will assist in
ensuring a continuous power supply. According to the CEA of India’s July 2021 report, the under-
construction of WSH projects is listed in Table 10. WSH energy projects with 1200 MW capacity
attached to the interstate transmission system (ISTS) are auctioned by SECI via a transparent,
competitive-bidding approach. SECI will discover the minimum tariff for the WSH project, and
the e-reverse auction was employed to select the winners/the hybrid project developers (HPD).
The project completion timeline is specified. SECI will sign a power-purchase-agreement (PPA)
with the hybrid energy developers. Both parties will enter into PPA for 25 years from the date
of the provision of PPA. SECI chose the HPDs, and they must set up the WSH project on a
build-own-operate (BOO)
53
basis and standard PPA.
Outcome
Systems utilizing renewable hybrid power can supply energy constantly at levels of expenditure and
dependability similar to those of coal-fired power plants. A hybrid system can incorporate wind and
solar with an additional resource of storage or generation. As the cost of battery storage and solar
energy declines, hybrid systems are anticipated to become more and more cost-competitive. The
state-wise WSH potential in India is discussed along with WSH power generation sites in India
based on NIWE. The National WSH policy-2018 and the amendment in guidelines for tariff-based
competitive bidding process for power procurement from grid-connected WSH projects issued by
the MNRE in 2021 are discussed along with the comparison of WSH policies of the various states
(Gujarat, Andhra Pradesh, and Rajasthan) with central government WSH policies. Low INR 2.67/
kWh pricing, comparable to simple solar tariffs, has so far attracted the SECI’s tenders for WSH
projects without storage. For a hypothetical WSH-lithium-ion battery storage design for the
Indian state of Tamil Nadu, the levelized cost of electricity (LCOE) production is currently INR
4.97/kWh and is predicted to drop to INR 3.4/kWh by 2030. In contrast, the price of electricity gen-
erated by new coal power plants in Tamil Nadu ranges from INR 4.5 to INR 6 per kWh. The success
of WSH initiatives heavily depends on the tariff developers can provide to their clients.WSH
project key players in India are discussed, and WSH project physical progress and commercial
details are elaborated. By 2023, India’s total WSH capacity, which is currently 0.148 GW, could
Table 9. WSH capacity tendered in India (others).
S. No.
Name of the
company
Capacity
tendered (MW)
Capacity
allotted
(MW)
Date of
issue
Annual
CUF (%)
Tariff
(INR/
kWh)
Commissioning
time line
1 Adani Green 700 Adani
Electricity
Mumbai
Limited
(AEML)
700 18.7.19 50 3.24 18 months
2 Tata Power
Mumbai
distribution
225 TATA
power
company
limited
225 13.7.20 35 2.59 18 months
20 Energy & Environment 0(0)
have increased by over 80 times to 11.6 GW. As more companies and developers look to capitalize
on the hybrid, the WSH market is anticipated to expand and change.
Feasibility study of WSH plant
Before drafting a system design, entering into contracts, or acquiring equipment, an evaluation of a
WSH project’s site and economic feasibility is essential in the development process that should be
accomplished early on. Feasibility studies evaluate significant project elements such as site viabil-
ity, resource potential, overall performance, and expense estimations.
54
The feasibility analysis
considers technical suitability, wind and solar resource features, anticipated performance of the
system, and the LCOE economic analysis. Wind turbines must be located far from one another,
leaving much-unoccupied space between them. Furthermore, the current allotment of energy evacu-
ation capacity is inefficient because wind and solar power are generated at various periods of the
day and in different seasons. As a result, addressing inefficiencies and poor resource usage is
crucial. Identification of places rich in both wind and solar energy and the construction of WSH
projects is an ideal solution for ensuring optimal land use, evacuation capacity, and shared infra-
structure. The main goal of designing WSH plants are as follows. (1) To increase the energy gen-
erated from the land (kWh/square meter). (2) To lessen the LCOE (INR/kWh). (3) To get the most
energy out of a transmission capacity (MWh/MW). (4) To enhance the energy generation’s balance
or variability (decreasing the peak-to-average ratio of produced power, lowering the coefficient of
variation for power production). (5) To align the load profile to the generation profile. The feasibil-
ity study flow chart has six steps. Figure 1 shows the design method for deploying the WSH project
in India. (1) Identifying a site for the WSH project. (2) Placement of wind turbines and energy yield
optimization. (3) Placement of solar module and energy yield optimization. (4) Optimize the end
capacity mixture. (5) Designing shared facilities and services. (6) Ensure that the environmental,
social, and governance (ESG) standards that apply to these projects are met.
Identifying a site for the WSH project
Any WSH project’s core methodology should begin with identifying locations with strong wind
and solar resources. It is critical for a WSH that both resources are adequate for maximizing the
advantages of the hybrid project. While a large part of India possesses ideal solar global horizontal
irradiance (GHI), excellent wind resources are limited to only a few states.
55
As a result, WSH
necessitates the identification of wind-rich sites followed by solar-rich ones. WSH’s primary
goal is to maximize energy output and cost reduction. As a result, location identification for
WSH plants is critical. (1) The energy generated from the land (kWh/square meter). Costs of deliv-
ered energy at the potential load centers or evacuation sub-station (INR/kWh). This will cover the
cost of production and the expenses of common infrastructure allocation and transmission to the
distribution point. After evaluating every technology, it will be derived as a weighted average
for the hybrid project. (2) There may be elements that make hybrid projects easier to undertake
in some places and more difficult in others. These considerations may include the ESG factors,
quality of existing infrastructure, climatic aspects, the complexities of geographical topography,
and the location of the project (defense, rural, urban, industrial, etc.). (3) Economic consequences
on the local community—a factor like “total economic value gain by the local community per kWh
of energy produced”might be utilized. Areas with adequate land-use-land-cover, infrastructure, and
connectivity can be discovered when areas with excellent wind resources can also optimize solar
resources can be recognized.
Charles Rajesh Kumar et al. 21
Figure 2 demonstrates the approach for the identification of the site. For the selected hybrid
zone at an altitude of 80 m, the yearly energy output from predominant wind turbine generators
(WTGs) will be determined. Initial data analysis for solar resource assessment can be done
using SolarGIS and the national renewable energy laboratory (NREL). The data obtained is
ground-vetted with the center for wind-energy-technology (C-WET) data. After choosing loca-
tions with abundant wind and solar resources, the land-use-land-cover mapping should be com-
pleted, with undesirable areas filtered out. Unsuitable sites can include the following. (1)
Monuments and heritage, national border areas, railways or seaports or airports, National or
state highway roads, national parks, surface water bodies, and build-up regions. (2) Sites
with a high risk of natural disasters (seismic and cyclonic) can be excluded. To reach the
site, it is vital to have suitable connectivity (waterways, roads, railways). Access roads are
needed to transport solar and wind power modules, the planning approach, the installation
and inspection crew, workers, and the transit of building materials. All factors relating to
access and connectivity must be confirmed during site inspections. The infrastructure and
power take-off facilities are critical considerations. The placement of the substation and its dis-
tance from the project site are crucial, as transmission infrastructure construction can signifi-
cantly increase project costs. The installation capacity of a WSH power plant is mainly
determined by the capacity of the nearest electricity substation.
56
Table 10. The under-construction and commercial details of WSH projects.
S. No. Name of the company
Scheme of
bidding
Scheduled
commissioning date Details
1 Mahoba Solar (UP) Private
Limited—Adani groups
Tranche I 10.07.21 Letter of award 25.01.19
PPA signed 7.11.19
Under Construction
2 SBE Renewables Ten Private
Limited
Tranche I 10.07.21 Letter of award 25.01.19
PPA signed 8.11.19
Under Construction
3 Adani Renewable Energy
Park (Gujarat) Limited
Tranche II 15.12.21 Letter of award 18.06.19
PPA signed 15.01.20
Under Construction
4 Renew Solar Power Private
Limited
RTC-1 07.04.23 Under Construction
5 AMP Energy Green Private
Limited
Tranche III 31.09.22 Letter of award 31.12.20
PPA signed July 21
6 Adani Renewable Energy
Holding eight limited
Tranche III 31.09.22 Letter of award 31.12.20
PPA signed July 21
7 ABC Renewable Energy
Private Limited
Tranche III 31.09.22 Letter of award 31.12.20
PPA signed July 21
8 ACME Solar Holdings
Private Limited
Tranche III 31.09.23 Letter of award 31.12.20
PPA signed July 21
13 Greenko Energies Private
Limited
Tranche VII 03.01.22 Under Construction
14 Renew Solar Power Private
Limited
Tranche VII 03.01.22 Under Construction
22 Energy & Environment 0(0)
Placement of wind turbines and solar module
The sites are chosen considering the ESG rules and guidelines. After determining the wind resource and
optimizing wind turbine installation, a shadow analysis should be performed to determine the best loca-
tion for solar modules. The solar module placement for the projects should be done in such a way as to
minimize energy loss due to shadows cast by moving wind turbine blades and other characteristics that
may cause errors and module damage as a result of hot spotting. The placement of solar panels must be
such that no shadow from the wind turbine lands on them from 10 a.m. to 4 p.m. The shadow flickers
can create frequent changes in light intensity, reducing solar energy output. Recent improvements in
inverter technology, such as dynamic maximum power-point-tracking (MPPT), allow for monitoring
and rapid adjustment of voltage levels for full power for the current.
The wind turbine safety area or safety zone can be calculated as the height of the hub +0.5 rotor
diameter +5 m. The safety zone is 172 m for a 2-MW wind turbine generator of G-114 Gamesa has
a rotor diameter of 114 and 106 m of hub height. The operating zone is the space around WTGs to
perform maintenance work of blades by keeping them in the ground without any difficulties. The
operating zone is calculated as 1.1 ×blade diameter. The empty zone will avoid shadows during the
highest production duration (10 a.m. to 4 p.m.). Depending on AC:DC ratio, tracker and tilt angle,
and pitch, various scenarios must be devised to optimize solar capacity installation. The DC:AC
ratio is the solar energy plant that has installed DC capacity to the inverter’s AC output.
57
The
choice of ratio is mainly determined by the inverter’s warranties, the site’s location, the trade-off
between decreased capital expenditure per unit of energy production, and the loss of power gener-
ated when generation exceeds inverter capacity. The traditional value of AC:DC is 1:1.25 and 1:1.1,
Figure 1. Design method of WSH plants.
Figure 2. Approach for identification of the site.
Charles Rajesh Kumar et al. 23
and a higher ratio can be 1:1.35. When all variables (configuration, AC:DC ratio, angle, pitch, etc.)
remain constant, annual power generation grows exponentially as DC overloading rises. The pitch
is the space among rows of modules that must be maintained to eliminate inter-row shading. Pitch
can be 7.5 or 5 m, etc. By raising the pitch, the yield loss can be avoided. Sun trackers, either single-
axis or double-axis, boost the annual average irradiation and increase energy yield by 20% and
30%, respectively. The comparative study of the dual-axis and single-axis tracker is shown in
Table 11.
The wind turbine and solar module flow chart placement are displayed in Figure 3. If wind speed
is higher than 8.50(m/s), it can be classified as first-class, 7.60–8.50(m/s), second-class, 6.60–
7.50(m/s), third class, 5.50–6.50(m/s) fourth class and less than 5.50 as a fifth class. The hybrid
plant should be designed with the highest generation and lowest cost in mind to achieve
maximum usage of area and resources. In addition, balanced solar and wind power generation
should be considered while deciding on the best capacity combination for a WSH plant. For
instance, the feasibility study on NTPC hybrid at Kudgi of Karnataka shows that the highest
power production was 13,286 MWh /year with an AC:DC ratio of 1:1.35 and a tilt angle of 10
degrees, and a pitch of 7.5 m. It is best to start with wind micro-siting. After shadow assessment,
solar modules must only be installed in the shadow-free region of wind turbines. It may be helpful
to analyze land ownership, land expansion expenditures, and other infrastructure before installing
solar modules on uneven grounds where WTGs are installed continuously at a considerable dis-
tance from one another.
The WSH can be carried out in four ways. (1) Greenfield WSH plant. (2) Brownfield WSH plant.
The brownfield is carried out in three ways. (a) Wind turbines are constructed on specific land
points, and solar panels are positioned around these turbines to evacuate from the wind evacuation
lines. (b) Solar modules must be put between wind turbines already erected on an adjacent parcel of
land. (c) Solar panels have already been installed, and wind turbines are erected on sites where solar
panels cannot be installed caused because of uneven landscapes and other land contour difficulties.
Developing a WSH stays the same for all of the above hybridization methods, with minor changes
from one form to another. Upgrades to evacuation capacity, regulatory permits for power sales, and
evacuation of excess generation, among other things, will need to be carefully considered.
Optimization of the evacuation mixture’sfinal capacity
The yearly energy forecast from a mixture of solar and wind power with various solar and wind
capabilities must be examined. Energy curves are analyzed to determine the optimum possible com-
bination for the hybrid plant’s energy mix that matches the project goals. Many scenarios will be
studied, and the best case will be selected based on optimizing the wind and solar capacity mix.
Table 11. The comparative study of dual-axis and double-axis trackers.
S. No. Parameter Dual axis tracker Single axis tracker
1 Generation of
energy
Raises by 25% Raises by 17%
2 Requirement of
land
Increase in area per MW of 80%–100%
(7–9 acres per MW)
Increase in area per MW of 30%–50%
(5–7 acres per MW)
3 Cost of the
structure
Raises by 50%–60% Raises by 40%–50%
4 Land leveling Not sensitive to undulating land Extremely sensitive to undulating land
24 Energy & Environment 0(0)
Figure 4 shows the optimization of the evacuation mixture’sfinal capacity. When solar and wind
capacity is combined, distinct generation curves emerge, which can be analyzed for balance. The
curves depict the generation pattern for various capacity mixtures, resulting in different solar and
wind generation ratios. A suitable mix would be selected, delivering energy closer to the customer
load. Optimizing the plant capacity mix for the lowest delivered energy cost is possible. For
instance, the WSH site at NTPC Kudgi of Karnataka state feasibility study shows the maximum
generation of 605,360 MWh/year with a tilt angle of 10 degrees pitch 7.5 m.
The lowest LCOE shown is 3.34 INR per kWh of energy. The optimal scenario is selected, enab-
ling cost-effective land and resource usage for a maximum generation. An analysis can be per-
formed for each Greenfield project to ensure optimum generation from the allocated land in the
most cost-effective way. Whether expense or generation can be compromised to some level may
vary slightly from project to project. The developer can pick between a scenario with maximal gen-
eration and a higher LCOE and a scenario with less generation and a lower LCOE.
58
Consider the
hybrid plant’s energy generation fluctuation for a better stable grid. The resultant hybrid’s hourly
peak can determine to average generation and variation coefficient of generation per hour. The
hybrid plant’s objective is to put the peak energy curve closer to the average energy curve, resulting
in the most negligible variation in generation from the average. The hourly peak-to-average gener-
ation ratio should be reduced, and the variation coefficient of generation per hour also should be
reduced to attain better grid balancing. In the case of hybrid plants, the relative variability in
power generation per hour is lower, resulting in a better optimal power generation curve.
P50, P75, or P90 calculations
Models are run utilizing the best data and techniques available to determine a site’s solar-wind
energy generation. The P50, P75, and P90 estimations are the results of the modeling. The prob-
ability figures are P50, P75, and P90. P represents the probability of exceedance. P50 denotes a
50% probability that the annual energy yield will exceed the P50 estimation. P50, a statistical
degree of confidence, indicates that we anticipate a 50% chance that the estimated solar resource
or energy yield will be exceeded. This also implies that the expectations may not be met with
the same probability. For some investors, the P50 level of confidence may indicate an unacceptably
large risk. As a result, alternative probabilities of exceeding the estimate are taken into account,
such as P90 (forecast exceeded with 90% probability) and P75 (forecast exceeded 75% of the
time). Lenders and investors often use P90 estimations to ensure enough energy is produced to
repay the project debts securely. There is a 50% possibility that the P50 level will not be attained
for P50, and there is a 10% possibility that the P90 level will not be attained for P90. Figure 5 shows
the normal distribution representation of P50 and P90 values.
Figure 3. Placement of wind turbine and solar module flow chart.
Charles Rajesh Kumar et al. 25
The data for the PV energy plant is processed and modeled utilizing PVsyst software. The
modeling of the wind turbine is done using the WASP software. In PVsyst software, under
the Energy management tab, initially, the “Inverter temperature”value needs to be considered
according to the inverter placement (e.g., Outdoor). Next to consider is the “power factor.”
Generally, the power factor is unity when an on-grid inverter is used. The power limitation
is considered. The power limitation is used when a capping of power is required. In India,
the capping of the net-metering system is 1 MW and beyond 1 MW plant, so injecting any
extra power into the grid is impossible. To restrict any extra power injection to the grid,
“power limitation”is utilized. Meteo variability is considered, which includes data source,
kind of data (monthly average values, TMY, multilayer, specific year, own measured),
climate change percentage value (0.5%–1%), and annual variability value (2.5% or 5%)
based on project capacity and location. Next is to consider simulation and parameter uncertain-
ties such as PV module modeling (1%), inverter efficiency (0.5%), soiling, mismatch (1%),
degradation estimation (1%), and custom variability (0%). The following parameters can be
considered for PV power plant design: module rating, PV array loss, short circuit voltage,
open circuit voltage, efficiency, total modules, inverter efficiency uncertainty, variance, deg-
radation uncertainty, and soiling and mismatch uncertainties. The following parameters can
be considered for wind power plant design: annual energy output (P90), losses, specific
yield, rotor diameter, average annual wind speed, and capacity.
Figure 4. Optimization of the evacuation mixture’sfinal capacity.
Figure 5. Normal distribution representation of (a) P50 and (b) P90 values.
26 Energy & Environment 0(0)
Designing shared facilities and services
WSH projects can be valuable assets for grid balancing since their generation curves are less vari-
able and enable the most efficient use of infrastructure. The small capacity can ride freely on the
evacuation capacity established for more significant projects where solar or wind capacity is less
than 30% of the overall capacity. For instance, when the power evacuation capacity is reduced
from 200 to 140 MW, generation losses rise from 0.08% to 5.96%, while the hybrid PLF increases
from 31.3% to 42.0%. When energy evacuation capacity is decreased, significant savings can be
acquired for some loss in a generation. The generated losses and transmission savings can be cal-
culated based on reduced power evacuation capacity. The generation loss must be within the devel-
opers’accepted level, and PLF must be appreciable. Based on the transmission point of connection
(POC) rate in various states, the net savings in the project at optimal evacuation capacity will vary
from one state to the other. As a result, power evacuation capacity should be maximized while min-
imizing generation losses. In the event of a WSH, power evacuation and metering are critical con-
siderations. The study suggests that the AC side incorporates solar and wind energy with common
feeder lines to transfer electricity to the pooling substation. This will result in cost reductions in the
evacuation infrastructure. WSH plants should have two-level metering at the generation and pre-
pooling substation stages. Common evacuation infrastructure can be employed for solar and
wind, maximizing savings from the WSH plant. Using energy storage with hybrid plants can
provide clear benefits.
59
(1) Decreasing transmission capacity significantly by storing excess power above the transmis-
sion capacity, released when production drops below transmission capacity. (2) Enhancing the
accuracy of the energy production schedule. (3) Meeting peak load by shifting energy generation
to peak load time. (4) By shifting energy production to the peak load time, peak load can be met. (5)
Equipping ride-through capability. The usage of energy storage necessitates a thorough investiga-
tion. Energy storage’s effect on transmission efficiency (MWh/MW) is shown in Table 12. MWh
per MW can be increased to 5769 from 2311 (a 150% increase), lowering transmission expenses.
Energy storage’s effect on reducing excess energy un-transmitted is shown in Table 13. Excess
power is left un-transmitted due to controlled transmission capacity, lessened with energy
storage. Power losses can be maintained at 3% with 2–3 hours of battery storage, even if transmis-
sion capacity is maintained at 40% of peak capacity. Energy storage is currently uneconomical due
to its high capital expenses. The utilization of power storage will not be helpful unless the generator
assumes accountability for the transmission of generated power.
Table 12. The impact of storing energy on transmission efficiency (MWh/MW).
S. No. Battery hours
The impact of storing energy on transmission efficiency
(MWh/MW)
“Transmission capacity”as a percentage of entire
nominal-capacity
40% 60% 80% 100%
1 3.00 5769 3622 2883 2311
2 2.00 5613 3708 2899 2311
3 1.00 5161 3837 2899 2311
4 0.25 4692 3852 2899 2311
5 0.00 4515 3852 2889 2311
Charles Rajesh Kumar et al. 27
The environmental, social, and governance standards relevant to WSH projects
Apart from the significant advantages, other ESG concerns associated with solar and wind power
plants should be recognized and avoided.
60
Authorities, shareholders, workers, consumers, and
partners must be on board with ESG compliance. The following issues must be addressed as
part of ESG compliance. (1) Compliance with environmental, health, and safety requirements
and reduce adverse effects on the environment, the local community, and the individuals
engaged in the business. (2) Having a good influence on the environment, society, and individuals
to maintain their consent for the industry, consequently increasing the support of all critical
stakeholders such as employees, customers, investors, and partners for business sustainability.
(3) Assuring stakeholder engagement in the business. During the development of the frame-
work, the following strategy can be employed. (1) Assessment of existing policies in India
for solar energy and on-shore wind projects in terms of safety, environment, social manage-
ment, and health. (2) Exploring the consequences of WSH installations on numerous social
attributes, environmental, safety, and health. (3) Pinpointing the minimum requirements that
must be met by wind and solar plants. (4) Suggestions for long-term governance and consequence
management. The ESG structure comprises four parts. (1) The first section includes a list of
project-related requirements. Most of these requirements apply to all infrastructure projects, including
WSH projects. (2) The framework’s second section lays out the rules for running and managing the
hybrid project regarding waste, noise, water use, social welfare, and influence on flora and wildlife,
among other things. (3) The framework’s third component lays the groundwork for a solid governance
mechanism that responsibly manages the company’s activities. (4) The final component outlines
various globally accepted ESG standards that are optional for locally funded projects (India-specific)
but necessary if the company wishes to be proactive in handling externalities when foreign money
is invested in the project. All four parts are interconnected and may share some standard parameters
and objectives.
Outcome
A feasibility study of the WSH plant is performed, and the primary design strategy for deploying
WSH power facilities in India is discussed. It covers every step of this process, from design tech-
nique to choosing and evaluating potential locations for such hybrid projects, optimally placing
wind turbines and solar panels, overall capacity mix for hybrid plants, and ultimately power evacu-
ation optimization. Additionally, a brief study of the savings from these hybrid plants and the ESG
Table 13. Energy storage’s effect on excess energy un-transmitted (%).
S. No. Battery hours
Energy storage’s effect on reducing excess energy
un-transmitted (Percentage)
“Transmission capacity’”as a percentage of entire
nominal-capacity
40% 60% 80% 100%
1 3.00 0.14% 0% 0% 0%
2 2.00 2.84% 0% 0% 0%
3 100 10.68% 0.37% 0% 0%
4 0.25 18.79% 3.74% 0.01% 0%
5 0.00 21.85% 5.96% 0.2% 0%
28 Energy & Environment 0(0)
standards which are necessary to implement these projects are provided. Finding suitable locations
with high wind speeds and significant irradiation would be a major obstacle. Along with increasing
the CUF, WSH projects with storage can handle peak demand generation. However, the availability
of land and policies such as co-location (requiring the location of the wind and solar) will remain
key monitorable for the viability of WSH projects. Technical problems like grid balancing and
proper transmission infrastructure would need to be resolved.
The degradation of the PV panels
The longevity and reliability of photovoltaic power plants are significantly impacted by the aging
and degradation of PV modules.
61
Degradation of the PV modules impacts the power plant’sfinan-
cial performance. The corrosion resistance and stability of the materials used to build a PV module
may affect how long it will operate—the durability of the bulk silicon PV modules shows a war-
ranty of up to 40 or 50 years. However, several degradation mechanisms and failure scenarios
could result in a module failure or a reduction in power output. It is crucial to analyze the PV
panels’lifespan performance and degradation. These mechanisms are almost universally linked
to temperature stress or water ingress. The PV module’s junction box, frame, and back and front
sides develop different kinds of faults due to the degradation of the PV module.
62
The most
common defects include milky pattern, encapsulant browning, formation of bubbles and delamin-
ation in the encapsulant, hot spots, busbar, polymer cracks in the back sheet, corrosion of junc-
tion box contacts, corrosion in the front grid and the anti-reflection coating and junction cables’
insulation degrading and discoloration.
63
Due to the increased activity of some degradation
modes, such as loose frames, string interlinks, junction box connection failures, light-induced
degradation, and glass breaking, the nominal power degradation rates tend to be larger during
the beginning period of operation than they do for the remainder of the operational life. The
degradation rate of the nominal power throughout its mid-life period is mainly impacted by
the anti-reflecting layer degradation, ethylene–vinyl acetate discoloration, cracked cell, and
delamination, which in turn lowers the short circuit current of the panels. Failure of the
diode, potential-induced degradation, and cell connection breakage are further defects that
occur at a lower level. The module is greatly affected by oxidation in its final years of life.
Theclimatesignificantly impacts how long PV modules last.
64
Solar module processing,
harsh environmental factors, lamination material, PV technology,
65
exposure time, solar track-
ing system, solar radiation concentration mechanism, and PV system voltage installation tech-
nique all play a role in PV module degradation. In light of this, stringent design certification and
type of approvals tests based on International Electro-technical Commission (IEC) standards
are conducted on PV modules in a controlled laboratory setting. These tests evaluate the
modules’reliability and quality and lower the PV modules’failure rate. Manufacturers of
PV modules also offer performance warranties to ensure the reliability and longevity of their
modules. The power degradation rate should be within 0.8% per year.
66
Outcome
According to NREL in India studies, rooftop systems in hotter climes may have higher solar panel
degradation rates than the median rate of 0.5% per year. It is crucial to develop new and more sen-
sitive methodologies for PV module quality checks and assurance that focus on qualification stan-
dards for particular climatic circumstances to increase the confidence of achieving the warranted
lifetime.
Charles Rajesh Kumar et al. 29
Carbon saving
The massive growth in coal usage almost certainly raises carbon intensity. The leading causes of
climate change are that 41% of carbon dioxide (CO
2
) emissions are produced by the electricity
sector, compared to 26% by industry, 25% by transportation, and 9% by buildings. Figure 6 repre-
sents Carbon dioxide emissions by various power sources. In recent years, the need for alternative,
low-carbon technological choices such as renewables has increased due to growing worries about
climate change, the health implications of environmental pollution, energy security, and access to
energy. Indian Government has prioritized the development of renewable energy, first and fore-
most, to cut emissions, achieve global climate targets, and seek more extensive socio-economic
benefits. Increased energy efficiency, deep electrification, and the deployment of renewable
energy sources will reduce carbon dioxide emissions from the energy sector by over 90% by
2050, putting the world on a path to achieving the Paris climate goals. Accelerated solar PV deploy-
ment among low-carbon technology choices can result in significant emissions reductions of 4.9 GT
of carbon dioxide in 2050, or 21% of the total energy sector emission mitigation potential. The Paris
Agreement provides a framework to keep the increase in global temperatures “far below 2°C,”and
ideally to 1.5°C. The global energy landscape must undergo a fundamental transition to achieve the
climate targets outlined in the agreement. The rapid adoption of low-carbon technologies in place of
traditional fossil fuel generation and consumption will enable such a change. Advances in hybrid
energy systems offer possibilities for creating and implementing cutting-edge green technologies
that can further cut emissions and attain net-zero emissions by 2050.
67
To accelerate the future
deployment of hybrid wind–solar capacities, it is essential to mitigate the current barriers immedi-
ately through various supportive government policies and implementation measures, including cre-
ative business models and financial instruments. In line with the goals of global decarbonization
activities, hybrid power systems, and technical spillover are likely to promote the green develop-
ment agenda.
68
In India, the Gujarat hybrid renewable energy park (30 GW, 72,600 ha) has
been under construction since December 2020 near Vighakot village near Kutch district. The
hybrid solar and wind power plant was compared to 90 million trees in that it would save 50
million tonnes of carbon dioxide annually.
Figure 6. Carbon dioxide emission by various power sources.
30 Energy & Environment 0(0)
Outcome
It is understood that CO and CO
2
emissions are the primary cause of global warming, glacier
melting, high rainfall in specific locations leading to severe flooding, and extreme draughts in
other regions. Concern over the scarcity of energy resources and the adverse effects of fossil
fuel emissions has led to rising demand for dependable, cleaner green energy sources. The WSH
plants are highly efficient and have the potential to lower carbon emissions. The WSH plants
show that substantial improvements may be made in cutting carbon emissions, improving energy
utilization, and lowering the effect of carbon emissions on the environment.
The size and choice of a hybrid solar–wind system for small-scale
irrigation
Recent developments in inverter technology allow for dynamic maximum power point tracking
(MPPT), which allows for fast voltage adjustments for maximum power for the current. Figure 7
shows the hybrid wind–solar system for small-scale irrigation based on the research. Figure 8
shows the size and choice of inverter for the hybrid wind–solar system for small-scale irrigation
based on the research. Figure 9 shows the size and choice of inverter for the hybrid wind–solar
system for small-scale irrigation based on the research.
Outcome
The most practical and cost-effective method of reducing electricity costs is a WSH energy system.
WSH plants offer a clean, renewable, non-polluting energy source while avoiding the high
expenses of extending grid power lines to remote locations. The WSH system for small-scale irri-
gation is discussed along with the size and choice of a hybrid wind–solar for small-scale irrigation.
The size and choice of the inverter are also presented, indicating that the WSH project is feasible.
As a result, the study will provide a few guidelines for energy consultants, engineers, and people
looking to install a WSH irrigation system for drip irrigation.
Main challenges of WSH plants and potential solutions and mitigations
WSH has advantages over standalone solar and wind. Compared to standalone wind and solar
energy expenditure, hybridization is expected to save 5%–7% in capital costs. Despite the potential
advantages of a hybrid energy system, some challenges and issues must be addressed. Policy uncer-
tainty, technical obstacles, and lower tariffs are all causing problems for developers in this sector.
The WSH energy industry has numerous obstacles. Political pressure, corporate influence, govern-
ment policies, a lack of enough battery storage, aging infrastructure, and the current market envir-
onment stand in the way of widespread adoption.
Land use challenges
(a) Tenders are likely to have a minimum CUF of 32%–38%, implying that most capacity must be
wind-based. On the other hand, installing a new wind capacity is difficult because most sound,
high-wind-potential grid-connected sites are saturated. Land restrictions have long been a sig-
nificant challenge in India’s renewable power business. Including a “co-location”option in
Charles Rajesh Kumar et al. 31
some tenders can be dismal for developers hoping for a more relaxed/flexible policy. It is
necessary to repower old wind turbines, particularly in Tamil Nadu, those nearing the end
of their useful lives.
(b) While solar energy projects are built on the contiguous ground, wind energy projects require
scattered lands on a footprint basis, increasing transmission and installation costs and the risk
of land-related concerns. Investors in the sector are concerned about these problems and
uncertainty.
(c) A big renewable energy scheme comprising massive WSH parks could not proceed due to a
lack of suitable land conducive to wind and solar development.
Technical challenges
(a) There are technical problems integrating solar and wind with the grid on the direct current
side. According to MNRE regulation, only alternating current integration is authorized until
the direct current metering system is in place. This diminishes the cost reductions linked
with DC integration in balance-of-system (BOS) usage.
(b) The plant size needed to optimize the generation portfolio varies by location, depending on the
amount of solar and wind power available. The best storage sizing is also a crucial consider-
ation. Due to the high capacity installation, there is a risk of underutilization on days when
renewable energy generation is high and storage is nearly non-existent.
Figure 7. The hybrid wind–solar system for small-scale irrigation.
32 Energy & Environment 0(0)
Figure 8. The size and choice of a hybrid wind–solar system for small-scale irrigation based on the research.
Charles Rajesh Kumar et al. 33
(c) Regulatory hurdles, market obstacles, and data and analytical skills are the three main impedi-
ments to energy storage implementation. For instance, the levelized tariff is INR 2.49 per kWh
when solar and wind are mixed at an 80:20 ratio and roughly INR 2.57 per kWh when 50:50.
However, when storage is included in a 2-hour battery backup, the levelized tariff jumps to
INR 4.59/kWh.
(d) To enable the combined function of solar and wind plants and encourage integration with
innovative technologies like energy storage systems, the government lags in promoting and
encouraging technological advances, techniques, and solutions for optimal and effective util-
ization of transmission infrastructure, land, and additional natural resources.
(e) The energy generated will be wasted unless a high-capacity storage system is installed. Most
critically, there is a shortage of power storage at a cheap rate. The storage system’s lifetime
and battery capacity have been enhanced due to technological advancements. Its exorbitant
cost prevents it from being widely installed. Battery prices must fall to make solar energy
storage more cost-effective.
(f) Due to a scarcity of skilled resources, there is currently a scarcity of expertise in developing
WSH installations.
(g) Aligning the planned commissioning date with connectivity and long-term access causes add-
itional delays.
(h) The concerns and obstacles to evacuation and integration of WSH include high transmission
and power storage systems prices, insufficient forecast precision, and inefficient despatch
optimization.
(i) Typically, developers do not factor in the power curtailment due to transmission limitations
while designing WSH projects. A fundamental difficulty is the lack of openness in the curtail-
ment (economic or technical) that developers encounter. Only after the project has been
commissioned and implemented do developers wonder why the actual revenue is less than
expected.
(j) Primary power is developed intermittently in a costly form to store and transport over
extended distances. An extensive array of tightly integrated storage, transmission, transform-
ation, backup, and demand management infrastructure is needed to make this power effective.
(k) The power grid’s most significant issue is its age, as most electric transmission and distribution
lines were built in the 1950s and 1960s. As a result, they cannot match the current demand and
the severe weather changes.
(l) Despite the government offering subsidies and other incentives for WSH energy, the fossil
fuel industry receives substantial government backing.
Figure 9. The size and choice of inverter for the hybrid wind–solar system for small-scale irrigation based
on the research.
34 Energy & Environment 0(0)
(m) WSH energy technologies are not widely accepted due to a lack of clear policies, support pol-
icies, incentives, subsidies, and restrictions. The renewable power market demands clear reg-
ulations and legal procedures to attract investment.
(n) Hot-spot heating reduces energy output and accelerates material degradation in the region.
(o) . Shadow formation because of rotating wind turbine blades results in a reduction in energy
production.
(p) The shadow flickers can create frequent light intensity changes, reducing PV energy output.
(q) Compared to pure-play wind or solar projects, WSH projects have more complicatedness in
design, execution of the project, operations, and maintenance. As a result, a consumer may
not be capable of investing in and maintaining hybrid projects independently and will have
to depend on established renewable power developers capable of providing renewable
power to consumers under captive-sale or third-party mode from WSH projects.
Environmental challenges
(a) The submitted policy for WSH projects is mainly mute on environmental, land, and community
concerns, which are increasingly taking center stage and affecting billion-dollar projects. The
WSH strategy most likely lacks a comprehensive social and ecological consequence evaluation
of green energy programs to understand their influence on the environment and communities.
One of the most common criticisms of the quick renewable energy transition is encroaching on
the fertile agricultural area and wreaking havoc on avifauna.
(b) India’s ambitions for WSH are vast, and if they are met, they will have significant negative
consequences for the environment and those living near such developments.
(c) No complete environmental impact studies were conducted before the construction of WSH
projects, and no details to ensure that environmental safeguards will be followed after an
active project. For example, many cases have been filed in the National Green Tribunal of
India against wind and solar projects threatening community pasture areas, agricultural
fields, and local wildlife. The severely endangered great Indian bustard (Ardeotis nigriceps)
is one of them.
Potential solutions and mitigations for the challenges
The government should designate a region with adequate infrastructure, including evacuation facil-
ities, where WSH project risks may be minimized. For installing WSH energy projects, land, trans-
mission, relevant infrastructure, and investor permits are required. These difficulties can be solved as
the sector evolves with consistent policies and standards. WSH will achieve traction if policy changes
are combined to eliminate technological inefficiency. Power management techniques should aim for
high system performance, reliability, and cost-effectiveness. Intermittent power can be reduced by
proper planning and precise forecasts of weather patterns, wind speed, and solar radiation.
Frequency, harmonic distortions, and voltage fluctuations are critical challenges in power quality
for stand-alone and grid-connected WSH plants.
69
Grid-connected WSH will have a more significant
impact when the grid is weak. The technical concerns can be addressed through design optimization,
improved quick response control facilities, and hybrid system optimization. WSH systems can be
linked in a common DC or AC bus, operating in grid-connected or stand-alone mode.
Table 14 shows the significant obstacles, probable remedies, and mitigation strategies for stan-
dalone WSH plants. Table 15 shows the significant barriers, possible solutions, and mitigation
Charles Rajesh Kumar et al. 35
strategies for the grid-connected WSH systems. The solar and wind energy capacity percentage may
be calculated using optimization approaches.
24
Various optimization methods are genetic algorithm
(GA), hybrid optimization model for electric renewable (HOMER) software, fuzzy logic, neural
network, and particle swarm optimization (PSO). The dynamic behavior of solar and wind
power plants is not captured by “iterative and artificial intelligence”technology. As a result, a
sizing method that decreases the system’s complexity and can describe the hybrid system’s fre-
quency response under dynamic settings must be modeled.
Outcome
WSH initiatives have been praised as the most practical solution to deal with the intermittent nature
of stand-alone wind and solar energy sources. In addition to maintaining grid stability, WSH and
efficient battery storage enable the nation to improve its land and transmission infrastructure. Land
use challenges, technical challenges, and environmental challenges are presented. In Rajasthan,
solar generation is higher than wind; in Karnataka, wind generation is higher than solar, and this
is challenging to co-locate the WSH projects. Forecasting wind energy is difficult, leading to under-
injection, and generators are forced to pay a penalty of four times for not meeting the forecasted
injection. Furthermore, there are curtailment issues with WSH projects across various states in
India. Setting up connectivity for WSH projects is also remaining challenging. Setting up new sub-
stations for WSH projects consumes much time. The potential challenges connected with WSH
technologies are examined in depth, and potential solutions and mitigations for the challenges
are provided.
Table 14. The significant obstacles and probable remedies and mitigation strategies for standalone WSH
plants.
S. No. Obstacles Potential solutions and mitigations References
1 Increased storage expense Integrating PV solar and wind energy reduces
storage necessities and, as a result, the overall
expense of the system.
70,71
2 Less usable energy throughout the
year
Renewable power production, battery energy
storage, and diesel generator backups are
integrated.
72–75
3 Fluctuating energy or quality of
power
Renewable power production combines fuel cells
or battery storage systems for energy storage,
and diesel generator backups are sometimes
used.
76–79
4 Devices for protection For safety purposes, relevant security
mechanisms must be installed, including
upgrades to current protection measures,
primarily when distributed generators are
used.
80
5 Running out of storage Fuel cells can be integrated with wind and solar
power sources.
81,82
6 Issues about the environment and
protection of batteries and
hydrogen tanks
Using fuel cells rather than massive
super-capacitors or Lead-acid batteries to
combine wind and solar energy sources results
in a non-polluting, stable power source with a
lower overall maintenance cost.
83
36 Energy & Environment 0(0)
Policy and regulatory recommendations based on the findings
Governmental solid and regulatory support is required for the significant expansion of WSH
systems. For national WSH policy, the following aspects must be examined. We have identified
the barriers and proposed recommendations for WSH policy 2018. Table 16 shows the recommen-
dations for the main barriers in the WSH policy based on the research.
(a) WSH policy of India provides no financial incentive or other tangible mechanisms to encour-
age the adoption of hybrid technology.
(b) WSH plants should receive incentives based on performance, such as MWh per MW trans-
ferred, peak-to-average ratio, plant load factor (PLF), etc.
Table 15. The significant obstacles and probable remedies and mitigation strategies for grid-connected WSH
plants.
S. No. Obstacles Potential solutions and mitigations References
1 Wind speeds and irregular
radiation from the sun cause
voltage instabilities.
(a) Employing active energy filters of shunt and
series configurations.
(b) Utilizing power compensators such as a
static compensator, switching, or fixed
capacitor.
(c) Customer equipment is sensitive to utility
line conditioning equipment, voltage
distortions, and power disturbances.
84 85 86
2 Frequency instability for sudden
shifts in active power by loads
(a) A PWM inverter controller regulates a
microgrid’s three-phase local AC bus
frequency and voltage.
87
3 Non-linear instruments and power
electronics gadgets produce
harmonics.
(a) Pulse width modulation (PWM) switching
converter and suitable filters.
88
4 Consequences of intermittent
power and network security
(a) Statistically accurate prediction and
scheduling systems can be employed. Using
regression analysis techniques and
algorithms to predict weather patterns, wind
speeds, and solar radiation.
(b) The system operator can decrease or
increase dispatchable production to
respond to any deficiency or excess in
renewable energy production.
(c) Flexible alternating current transmission
systems and automatic generation control
are two state-of-the-art fast-reaction control
services.
89 90 91
5 Synchronizing The phase-locked loop (PLL) is the most often
used grid synchronization method. Two other
synchronization strategies are detecting grid
voltages crossing zero or utilizing a set of
non-linear filers applying the transformation.
92
Charles Rajesh Kumar et al. 37
Table 16. The recommendations for the main barriers in the WSH policy.
S. No. Factors Obstacles Recommendations
1 Availability of land, forest
clearances, and allocation
1. Developers’troubles are exacerbated by complicated
land-related legislation and the lengthy process of
revenue land allocation.
2. High costs for forest lands with increased wind potential
lead to higher power production costs, and the
complicated process of obtaining rights demotivates
project developers.
3. Approval of coastal regulation zone (CRZ).
4. Approvals of the Air force department and defense
ministry.
5. Clearance from state nodal agencies.
6. Approval from the Ministry of mines.
1. All issues should be cleared and authorized by a
single national nodal agency.
2. The permission and clearance procedure for land
use should be less complex.
3. A thorough and extended period examination of
the site and WSH potential information must be
required before the start of the project to avoid
non-productive land usage and allotment.
4. The area around wind turbine farms sits unused
and vacant, which could be used for solar energy
production.
5. Installing wind turbines in the periphery or
enclosing region of existing solar energy projects
can be used to hybridize them, as long as they do
not interfere with the solar projects’energy
production. The goal of getting the most out of land
and space by combining wind and solar PV projects
is a promising energy-generating source.
2 Power evacuation
arrangements and power
grid stability.
1. WSH project developers, technology providers, and
transmission agencies (utilities) are all responsible for
power evacuation.
2. Numerous institutions, such as the Central Electricity
Authority (CEA), Power System Operation
Corporation (POSOCO), and Power Grid Corporation
of India Limited (PGCIL), must all provide their approval
for the project infrastructure to be built. The inclusion of
several government agencies makes the clearance
procedure for project developers complicated and
time-consuming, causing a delay in project start-up.
3. Wind energy fluctuates often, and solar-based energy
1. The policy should distinctly state the developers,
utilities, and technology suppliers’responsibilities
for power evacuation.
2. All issues should be cleared and authorized by a
national nodal agency for power evacuation.
3. The stability of grid issues can be addressed by
efficient and effective grid management, resulting
in lower everyday operating expenses and
increased system utilization.
93
(continued)
38 Energy & Environment 0(0)
Table 16. Continued.
S. No. Factors Obstacles Recommendations
fluctuates continuously, causing impulsive instabilities, a
big challenge for grid security and disciplines.
3 Absence of explicit the
policy guidelines
Absence of a complete explanation in the announced WSH
policy.
An enhanced version of policies with clear and
comprehensive descriptions.
4 Technological capability/
competency
1. The project developers are frequently conflicted
between making machines in India and importing
machinery from a more technologically sophisticated
country that may provide excellent items at a lower cost.
The ultimate selection is made depending on the system’s
total cost.
2. Choice of suitable technology for the project.
3. Project developers’technical ability in data gathering,
planning, and project scheduling.
4. Other nations’policy changes have an impact on the
system’s expenses. Furthermore, the quality of the
power system’s components also plays a vital role.
5. Per the ‘Suryamitra’Program, poor craftsmanship is to
blame for 35% of the difficulties and flaws in
solar-rooftop modules. There is a shortage of technically
trained people resources, mainly residential solar PV
systems.
1. Concentrate on research and development in the
right way.
2. Before the construction of a project, long-term
collection of data is necessary.
3. The development of superior power technologies
for obtaining more additional power from
renewable resources at a reduced expenditure is
required as solar and wind increase in popularity.
5 The risks of off-takers 1. The developers are constantly anxious about whether
distribution companies would buy the energy at a
reasonable cost, which involves the danger of them
pulling back.
2. Norms of long-term open access (LTOA).
1. In its policy, the MNRE should consider the
interests and aspirations of stakeholders.
2. There should be proper price control depending
on market conditions.
3. The RPO’s content and execution should be
checked regularly, enforced/bounded, and firmed
so that off-takers may be confident that the
distribution companies would acquire the
generated energy with suitable payment
(continued)
Charles Rajesh Kumar et al. 39
Table 16. Continued.
S. No. Factors Obstacles Recommendations
securitization via the letter of credit (LC) method.
Off-takers’risks will be reduced as a result, and
they will be motivated to generate more renewable
energy.
6 Uncertainty in policy 1. The frequent policy changes, such as the elimination of
generation-based incentives (GBI), an accelerated
drop-in depreciation (AD) percentage, the withdrawal of
the tax deduction for infrastructure development under
the income tax act of section 80 IA, and the transition to
competitive bidding from preferential FIT discouraged
project developers. The frequent policy changes
negatively impacted the renewable energy generation
industry.
2. Geopolitical concerns such as reopening long-term PPAs
already been signed by different state governments have
undermined investors’trust.
1. A standard policy framework and guidance
documents comparable “one-nation and
one-power tariff”are urgently needed.
2. These regulations must be efficient and enforceable
during the project’s lifecycle to achieve successful
results with no changes.
3. Policy changes must be less frequent.
4. The revised amendment should not intervene in
ongoing projects unless absolutely necessary.
7 Constantly switching global
scenario
1. Shifts in the global economic scenarios.
2. Technological advancements and, as a result, price
reductions.
3. Deviations in nations’export and import policies
The purchasing agreement should be sufficiently
adaptable to account for increases in energy
production due to technology advancements and
tariff updates according to market conditions.
8 Captive-utilization for
demand-supply
The maximum proportion of wind energy used is 100% to
satisfy contract demand. The total amount of solar energy
used to meet contract demand is 50%. As a result, the
existing policy openly discriminates against wind and other
renewable power sources, such as solar energy projects. It
is thus seen as a roadblock to unbiased renewable energy
implementation.
The captive strategy for completing demand-supply
must be identical for all renewable power sources,
including solar and wind power.
9 Policies on imports and
manufacturing
Together with renewable energy policies, manufacturing and India should build a conducive manufacturing
atmosphere by providing adequate governmental
(continued)
40 Energy & Environment 0(0)
Table 16. Continued.
S. No. Factors Obstacles Recommendations
import policies impact the techno-economic status of
renewable energy-based power plants.
assistance and corporation tax relief to producers to
minimize import volume and secure its global
market position.
10 Other barriers 1. Functional uncertainties of the energy project given the
degradation of technology.
2. Grid code poses technology risks in the power mix, such
as low-voltage-ride-through (LVRT) and
High-voltage-ride-through (LVRT).
3. Risks of policies and regulations.
4. Geopolitical concerns.
5. Credit risks and distribution companies’solvency.
An enforceable Letter of Credit (LC) method could
help alleviate the DISCOM solvency problem.
Charles Rajesh Kumar et al. 41
(c) Because solar and wind resources frequently have complementary generation patterns, hybrid
projects can decrease energy output variability and enhance grid stability. This is statistically
valid, although the advantage is difficult to quantify.
(d) Acquiring wind data is critical to achieving a successful wind–solar hybridization for the
project site.
(e) Overlaying wind turbines on a functioning solar installation or vice versa is nearly impossible.
Furthermore, the chances of producing novel hybrid plants are limited to opportunistic occur-
rences, which necessitate a stronger push.
(f) Existing wind projects will be hard to hybridize because they are subject to a feed-in tariff
regime, while new costs are substantially lower.
(g) The MNRE will have to develop specific guidelines to ensure how the existing solar and wind
installations can be converted to hybrid and that the tariff is calculated correctly. The MNRE
should look at the new solar tariff, calculate a weighted power average, and develop a standard
tariff.
(h) There are three sub-categories within this solar-wind hybrid project area (wind, solar, and
hybrid), each with policy challenges. Firstly, both solar and non-solar renewable purchase
obligations must be addressed. Second, there would be a requirement to address land
issues. Third, if a hybrid plant is being developed, with potential from wind and solar, the
question is what proportion should be pursued.
(i) All Indian states must develop a hybrid policy and laws for evacuation and metering to encour-
age hybrid at the state level; otherwise, this policy will stay national.
(j) Even if the developer can save money on transmission expenses, it usually only accounts for
around 5% to 8% of the entire capital cost, but it can raise the risk of curtailment.
(k) The policy should include information on locating and purchasing wind–solar resource-rich
sites to build WSH parks. A sequence of pre-identified sites would boost investor trust
while lowering development risks. Likewise, only wind or only solar power plants should
not be permitted to operate on such sites.
(l) A suitable definition of “capacity”should be defined by “transmitted power”and not “nominal
peak capacity”to identify the effective transmission for WSH.
(m) Metering for WSH systems should be enabled at multiple levels to use shared evacuation
(internal).
(n) Solar and wind energy resources can be combined on the same parcel of land, resulting in
higher final output and the use of shared auxiliary and transmission infrastructure.
(o) . To progress, a competitive private investment must be at each WSH energy harvesting
process level.
(p) To avoid oversizing, the government must consider structuring bids for WSH projects with
storage incorporating CUF.
(q) Discard the current practice of collecting transmission charges per unit and instead levy trans-
mission charges on the total capacity. This will incentivize developers to optimize their hybrid
projects so that transmission prices are as low as possible, unlike the current system, which has
transmission charges twice as high as conventional energy.
The secondary renewable energy source’s capacity should not be associated with the rated power
capacity of the primary renewable power source for the project to be classified as a wind–solar
hybrid. There should be no limit on the minimal storage capacity for a power storage project
that includes a source of energy.
42 Energy & Environment 0(0)
Outcome
In India, the development of large-scale WSH projects is still in its early stages, and more
research is required to explore technical, commercial, and policy elements that influence
project design. The policy suggestions for improvement of the WSH project are provided.
The WSH project developers, potential investors, stakeholders, innovators, policymakers, man-
ufacturers, designers, and researchers will benefit from the recommendations based on the
review’sfindings. The proposed policy will encourage the creation of solutions and scientific
progress in WSH power production.
Conclusion
Several difficulties for the WSH sector include reducing production expenditures, consumer
awareness, expanding R&D activities, higher standards, and increased financial assistance. It
is essential to overcome these obstacles for the WSH technology to keep growing and get wide-
spread acceptance. Gujarat, Andhra Pradesh, and Rajasthan are among the states that have
developed their WSH policies. More states should fall into line and develop consistent policies
with the national WSH policy of 2018. States can set aside a particular amount of their renew-
able power goals for WSH and boost the form of exemptions and subsidies to enable the market
to flourish. Developers should be able to choose whether or not to use the co-location criterion
to identify the best sites for their plants. SECI has regularly announced major tenders to
scale-up market expansion. Rather than traditional solar or wind bids, the government now
intends to arrange renewable power auctions for round-the-clock and WSH projects. The
goal is to eliminate erratic power supply and create sustainable energy that is more cost-
effective than traditional thermal facilities. Furthermore, the government must consider struc-
turing bids for WSH projects with storage incorporating CUF to avoid oversizing. Decreasing
battery costs and a growing percentage of renewables in the whole generation portfolio will
accelerate battery storage usage, evolving into a critical component of the overall energy gen-
eration mix. Incorporating battery storage is certainly not a viable solution because it dramat-
ically raises project expenses and, as a result, tariffs. On the other hand, the lowering trend in
battery pricing will make the WSH projects viable in a few years and deliver more consistent
electricity. Compared to a standalone wind or solar facility, a WSH plant requires less storage
capacity to stabilize the grid, lowering the cost of power. The following are some of the imme-
diate steps that can be taken to facilitate WSH growth: RECs can be implemented more quickly
and efficiently, using carbon trading as an income source; improving financial assistance,
encouraging private investment, and implementing the net metering concept and mixing pol-
icies; fast deployment of grid-powered energy; off-grid developments in various applications,
such as cellular towers, and fostering localized mini-grids in locations where there is currently
no connectivity. Research and development efforts must be bolstered in the private industry and
academic institutions. The necessity to create infrastructure for new enterprises emerging from
the development of substantial WSH projects will lead to the formation of millions of product-
ive employees. In addition to environmental and power accessibility reimbursement, publiciz-
ing employment generation would enhance the economic case for renewable energy policies
and increase support from the public for the WSH programs. The government, corporate
sector, and society working together will usher in a revolution in developing WSH power in
India. If these measures go as planned, India’s aim of becoming a world leader in the WSH
energy sector will soon become a reality.
Charles Rajesh Kumar et al. 43
Declaration of conflicting interests
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publica-
tion of this article.
Funding
The authors received no financial support for the research, authorship, and/or publication of this article.
ORCID iD
J Charles Rajesh Kumar https://orcid.org/0000-0003-2354-6463
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J Charles Rajesh Kumar received the Bachelor of Engineering degree in Electronics &
Instrumentation Engineering from the Madurai Kamaraj University, India, the Master of Engineering
degree in Electronics & Communication Engineering from Anna University, India, and Master of
Business Administration degree in Financial Management from the Indira Gandhi National University,
India. He was bestowed the Gold medal for excellence in Master of Engineering degree by Anna
University in 2008. He has been a faculty member of Engineering at various Universities of repute in
India and abroad. He serves as a reviewer and published many research articles in peer-reviewed journals
in the Web of Science, Science Citation Index, and Scopus databases. His current research involves VLSI
design, System on Chip (SoC), Network on Chip (NoC), Embedded Systems, Wireless sensor networks,
Artificial intelligence, Machine Learning, Robotics, Video coding, Image processing, IoT and Renewable
energy.
MA Majid received the MSc degree in Electrical Engineering from King Fahd University of
Petroleum and Minerals (KFUPM), Dhahran, Saudi Arabia, in 2002. In 2011, he was awarded
his PhD degree in Electronic and Electrical Engineering from the University of Sheffield in the
48 Energy & Environment 0(0)
UK. He was an EPSRC Prize Postdoctoral Fellow at The University of Sheffield for one year
(2011–2012). From 2012 to 2015, he continued as a postdoctoral fellow in the electrical engineer-
ing program at King Abdullah University of Science and Technology (KAUST), Saudi Arabia.
Currently, he is an Assistant Professor in the Electrical and Computer Engineering Department,
Effat University, where he is engaged in applying III/V semiconductor quantum dot/quantum
well devices to applications such as Renewable energy, Biomedical imaging, Optical communica-
tions, and solid-state lighting.
Charles Rajesh Kumar et al. 49
