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Citation: Silalahi, D.F.; Blakers, A.
Global Atlas of Marine Floating Solar
PV Potential. Solar 2023,3, 416–433.
https://doi.org/10.3390/
solar3030023
Academic Editors: Wei-Hsin Chen,
Aristotle T. Ubando, Chih-Che Chueh
and Liwen Jin
Received: 20 June 2023
Revised: 21 July 2023
Accepted: 25 July 2023
Published: 27 July 2023
Copyright: © 2023 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Article
Global Atlas of Marine Floating Solar PV Potential
David Firnando Silalahi * and Andrew Blakers
School of Engineering, The Australian National University, Canberra, ACT 2600, Australia;
andrew.blakers@anu.edu.au
*Correspondence: david.silalahi@anu.edu.au
Abstract:
In this paper, we analyse 40 years of maximum wind speed and wave height data to identify
potential sites for solar photovoltaic (PV) systems floating on seas and oceans. Maximum hourly wave
height and wind speed data were segregated into 5 distinct categories. These categorisations were
then combined at the nearest wind speed and wave height grid point for each sea location, generating
a comprehensive wind–wave map via a geographic information system (GIS) visualisation. We find
that regions around the equator are generally calm, i.e., free from strong winds and large waves. The
most favourable locations are around the Indonesian archipelago, and the Gulf of Guinea on the west
coast of tropical Africa. Our analysis indicates the huge potential of floating solar PV systems in calm
tropical maritime regions, capable of generating about one million terawatt-hours per year in regions
that rarely experience waves larger than 6 m or winds stronger than 15 m/s. This study furthers
our understanding of alternative renewable energy options, emphasising the promising potential of
offshore floating solar PV systems in the global energy transition.
Keywords:
solar PV potential; floating solar PV; marine solar PV; wave and wind analysis; solar
energy resource assessment
1. Introduction
Demand for energy is likely to rise greatly by mid-century due to a growing global
population, increased per capita energy consumption (correlated with affluence), and
electrification of transport, heating, and industry. There is an urgent need to reduce carbon
emissions to address the intensifying climate crisis. This challenge requires solutions that
can not only fulfill increasing energy needs but also contribute to zero-carbon targets. The
leading solution is solar PV technology, with support from wind energy. In 2022, more new
solar PV [1] generation capacity was installed than everything else combined.
The International Energy Agency (IEA) projects that the world’s electricity demand
will grow to around 60,000 terawatt-hours (TWh) by 2050 compared to current levels [
2
],
even after considering increased energy efficiency measures. The International Renewable
Energy Agency (IRENA) projects that world electricity generation will nearly double to
about 50,000 TWh in 2050 [
3
]. Typical per capita electricity consumption in developed
economies is 6–12 megawatt-hours (MWh) per person [
4
]. This may double to around
20 MWh per capita [
5
] to accommodate electrification of most energy functions. According
to the United Nations, the world population is expected to approach ten billion people
by 2050 [
6
]. Thus, global electricity demand may eventually approach 200,000 TWh per
annum.
The power and area of solar panels required to supply 20 MWh of electricity per capita
per annum are 14 kilowatts (kW) and 70 m
2
, respectively, assuming an average capacity
factor of 16% [
7
] and an array solar conversion efficiency of 20%. For ten billion people,
this amounts to 140 TW and 0.7 million km
2
, respectively. This can be compared with
the global land surface area of 150 million km
2
and the area devoted to agriculture of
50 million km2[8].
Solar 2023,3, 416–433. https://doi.org/10.3390/solar3030023 https://www.mdpi.com/journal/solar
Solar 2023,3417
The simple calculation above shows that the world has sufficient land area to provide
energy from solar PV for ten billion affluent people. However, in some regions, there are
constraints on provision of sufficient solar energy. These include small countries, regions at
high latitudes, regions with high population density, and regions with large fractions of
protected land that are unavailable for energy infrastructure. In many such regions, wind
energy can provide large fractions of required energy. For example, offshore wind [
9
] in
the Sea of Japan, the North Sea, and the Northwest Atlantic Ocean has immense potential.
Strong interregional transmission helps to cover shortfalls in solar or wind availability by
smoothing out local energy demand and renewable energy supply over large areas.
Floating solar panels have the potential to provide very large-scale energy in some
regions. Floating solar, also known as floatovoltaics, involves installing solar panels on
floating structures on bodies of water (Figure 1). The panels can be floated on inland
lakes, artificial reservoirs, quarry lakes, or irrigation canals. Additionally, they can be
located in maritime areas that are not subject to excessive wind speeds or wave heights.
Floating solar PV (FPV) can have advantages over land-based systems, such as reduced
land requirements, higher energy yield due to the cooling effect of water [
10
], and potential
synergies with existing water infrastructure [11].
Solar 2023, 3, FOR PEER REVIEW 2
with the global land surface area of 150 million km
2
and the area devoted to agriculture
of 50 million km
2
[8].
The simple calculation above shows that the world has sufficient land area to provide
energy from solar PV for ten billion affluent people. However, in some regions, there are
constraints on provision of sufficient solar energy. These include small countries, regions
at high latitudes, regions with high population density, and regions with large fractions
of protected land that are unavailable for energy infrastructure. In many such regions,
wind energy can provide large fractions of required energy. For example, offshore wind
[9] in the Sea of Japan, the North Sea, and the Northwest Atlantic Ocean has immense
potential. Strong interregional transmission helps to cover shortfalls in solar or wind
availability by smoothing out local energy demand and renewable energy supply over
large areas.
Floating solar panels have the potential to provide very large-scale energy in some
regions. Floating solar, also known as floatovoltaics, involves installing solar panels on
floating structures on bodies of water (Figure 1). The panels can be floated on inland lakes,
artificial reservoirs, quarry lakes, or irrigation canals. Additionally, they can be located in
maritime areas that are not subject to excessive wind speeds or wave heights. Floating
solar PV (FPV) can have advantages over land-based systems, such as reduced land re-
quirements, higher energy yield due to the cooling effect of water [10], and potential syn-
ergies with existing water infrastructure [11].
Figure 1. Floating solar PV system with its components. Image from Solar Energy Research Institute
of Singapore [12].
Applications of FPV systems in freshwater environments have been discussed
widely. Limitations on freshwater floating solar PV systems include availability of water
bodies, conflict with alternative water uses, and potential environmental impacts.
Offshore floating solar PV is an attractive option for large-scale solar energy produc-
tion in some regions. Constraints include salt rather than fresh water, strong winds and
large waves in many regions, and conflict with fisheries and environmental values. How-
ever, there is vast potential for maritime FPV because seas and oceans are very large. In
many of the world’s densely populated areas, electricity demand centres are located close
to coastal regions. Approximately 40% of the world’s population lives within 100 km of
coastal regions [13].
To date, limited research has been conducted on assessing the suitability of ocean
surfaces for floating solar PV sites. This study addresses this research gap by assessing the
potential of ocean surfaces for floating solar PV sites. Preferable places for maritime solar
panels are those where maximum wave heights and wind speeds are low because this
reduces the cost of the engineering defences required to protect the panels.
Figure 1.
Floating solar PV system with its components. Image from Solar Energy Research Institute
of Singapore [12].
Applications of FPV systems in freshwater environments have been discussed widely.
Limitations on freshwater floating solar PV systems include availability of water bodies,
conflict with alternative water uses, and potential environmental impacts.
Offshore floating solar PV is an attractive option for large-scale solar energy production
in some regions. Constraints include salt rather than fresh water, strong winds and large
waves in many regions, and conflict with fisheries and environmental values. However,
there is vast potential for maritime FPV because seas and oceans are very large. In many of
the world’s densely populated areas, electricity demand centres are located close to coastal
regions. Approximately 40% of the world’s population lives within 100 km of coastal
regions [13].
To date, limited research has been conducted on assessing the suitability of ocean
surfaces for floating solar PV sites. This study addresses this research gap by assessing
the potential of ocean surfaces for floating solar PV sites. Preferable places for maritime
Solar 2023,3418
solar panels are those where maximum wave heights and wind speeds are low because
this reduces the cost of the engineering defences required to protect the panels.
In this study, a set of 40 years of maximum hourly wind speed and wave height data
was analysed to map the preferable sites for floating solar PV. The largest wave heights
and wind speeds experienced during the years 1980 to 2020 were selected to characterise
suitability, since it is maximum values that drive the cost of engineering defences. The
ocean’s surface covers 363 million km
2
, which is about 72% of the earth’s surface [
14
]. The
scope of this research encompasses sea and ocean surfaces within 300 km of land. The
analysis is conducted at a spatial resolution of 11 km to provide an assessment of the
potential for maritime floating solar PV sites. This study is the first comprehensive survey
of the scope required for maritime floating solar PV that considers factors such as hourly
maximum wave height and hourly maximum wind speed. This study is not concerned
with developing new floating solar PV technology.
2. Materials and Methods
2.1. Floating PV Technology
Being in open ocean environments, offshore floating solar PV systems can benefit
from more consistent and stronger solar irradiance due to the reduced effects of shading
and cloud cover [
15
]. This can lead to higher energy yields and increased overall system
efficiency compared to their freshwater counterparts.
Floating solar PV systems can be deployed in areas where there is limited land avail-
ability for ground-mounted solar panels. Floating solar PV systems can be combined with
wind turbines to create hybrid systems that have higher combined capacity factors than
either alone and that share transmission and grid connection points [16].
While the potential for floating solar PV systems in freshwater bodies has been widely
studied, the exploration of ocean-based floating solar PV systems remains limited. A
recent study by Oliveira-Pinto [
17
] provides a good literature review of the potential of
offshore floating solar PV, available technologies, technical challenges, and risks of offshore
floating solar PV. Ocean environments offer abundant surface area, potentially allowing
for large-scale deployment of floating solar PV systems [
18
]. Floating PV performs slightly
better, on average, on an annual basis than neighbouring land-based systems [19].
However, offshore floating solar PV systems also face several challenges and limita-
tions, including corrosion risk from salt water, fouling by marine organisms, the need for
robust and reliable floating structures, mooring, and anchoring systems that can withstand
harsh marine environments, as well as potential ecological and environmental impacts on
marine ecosystems. Strong winds and large waves can cause major damage [
20
]. Ensuring
safety and reliability under varying wave and wind conditions is crucial for the successful
deployment of floating solar panels. Despite the increasing interest in floating solar PV
technology, a comprehensive global atlas of floating solar PV potential remains lacking,
which hinders effective energy policy and planning.
The amount of floating solar PV installed globally in 2021 was around 3.8 GW [
21
]. A
large floating solar PV plant with a capacity of 320 MW has been constructed in China [
22
].
The future expansion of floating solar PV is expected to be driven by Asian countries such
as China, Indonesia, India, South Korea, Thailand, and Vietnam [
21
]. South Korea has a
target of 2.1 GW of solar floating PV. The land-scarce country has permitted a 1.2 GW solar
floating PV power project in North Jeolla. The project is expected to operate commercially
in 2025 [23]. The worldwide capacity of floating PV is projected to rise to about 30 GW by
2030 [
22
]. Figure 2shows real and projected cumulative global installed capacity of floating
PV from 2011 to 2030.
Ocean Sun, a Norway-based floating solar company, constructed a two-floater 0.5
MWp system in the Yellow Sea, outside Shandong, China, in October 2022. It is an
integrated FPV with offshore wind [
13
]. The pilot project is part of Shandong Province’s
plan to install a total of 42 GW of offshore floating solar [25].
Solar 2023,3419
Solar 2023, 3, FOR PEER REVIEW 4
Figure 2. Cumulative global installed capacity of floating PV. Data source from [12,22,24].
Ocean Sun, a Norway-based floating solar company, constructed a two-floater 0.5
MWp system in the Yellow Sea, outside Shandong, China, in October 2022. It is an inte-
grated FPV with offshore wind [13]. The pilot project is part of Shandong Province’s plan
to install a total of 42 GW of offshore floating solar [25].
2.2. Wind and Wave from ERA5 Reanalysis
Long-term wind and wave data are required to assess the engineering defences re-
quired to minimise the risk of damage to floating PV. The ERA5 reanalysis is used in this
study. The ERA5 is a global climate and weather reanalysis tool from the European Centre
for Medium-Range Weather Forecasts (ECMWF) [26]. The ERA5 reanalysis dataset, pro-
vided by the European Centre for Medium-Range Weather Forecasts (ECMWF), offers
hourly weather, climate, and environmental data globally. It combines past weather data
with models to infer past values of weather variables such as wind speed and wave height.
This allows users to study past climate conditions, track current weather patterns, and
make statistical predictions about the future climate. ERA5 has a higher temporal and
spatial resolution than previous global reanalyses, and it can provide more detailed infor-
mation about the state of the atmosphere at different times and places, which can lead to
more accurate predictions of weather patterns and climate change [27]. After the initial
release of ERA5, several independent studies evaluated its performance. The studies
found that ERA5 performs well in representing wind, temperature, and humidity in the
Arctic [28] and Antarctic [29]. ERA5 performs well in representing surface and low-level
winds over the ocean, relative to observations and other reanalyses [30–32]. ERA5 has
been shown to outperform MERRA2 in wind energy modelling [31]. When comparing
ERA5 data to in-situ observations from 103 buoys in the North American Atlantic and
Pacific collected by the National Data Buoy Center between 1979 and 2019, ERA5 SWH
shows generally good performance across most stations. The accuracy of ERA5 estima-
tions of significant wave height is satisfactory under the most typical sea states of between
0.5 m and 4 m [33].
However, while ERA5 is widely respected for its accuracy, it is not perfect. Its reso-
lution may not be high enough to capture all local weather phenomena, especially those
that occur at smaller scales than ERA5 grid-size data, such as severe wind gusts. Addi-
tionally, reanalysis data are based on both observations and model simulations, which
Figure 2. Cumulative global installed capacity of floating PV. Data source from [12,22,24].
2.2. Wind and Wave from ERA5 Reanalysis
Long-term wind and wave data are required to assess the engineering defences re-
quired to minimise the risk of damage to floating PV. The ERA5 reanalysis is used in
this study. The ERA5 is a global climate and weather reanalysis tool from the European
Centre for Medium-Range Weather Forecasts (ECMWF) [
26
]. The ERA5 reanalysis dataset,
provided by the European Centre for Medium-Range Weather Forecasts (ECMWF), offers
hourly weather, climate, and environmental data globally. It combines past weather data
with models to infer past values of weather variables such as wind speed and wave height.
This allows users to study past climate conditions, track current weather patterns, and make
statistical predictions about the future climate. ERA5 has a higher temporal and spatial
resolution than previous global reanalyses, and it can provide more detailed information
about the state of the atmosphere at different times and places, which can lead to more
accurate predictions of weather patterns and climate change [
27
]. After the initial release
of ERA5, several independent studies evaluated its performance. The studies found that
ERA5 performs well in representing wind, temperature, and humidity in the Arctic [
28
]
and Antarctic [
29
]. ERA5 performs well in representing surface and low-level winds over
the ocean, relative to observations and other reanalyses [
30
–
32
]. ERA5 has been shown
to outperform MERRA2 in wind energy modelling [
31
]. When comparing ERA5 data to
in-situ observations from 103 buoys in the North American Atlantic and Pacific collected
by the National Data Buoy Center between 1979 and 2019, ERA5 SWH shows generally
good performance across most stations. The accuracy of ERA5 estimations of significant
wave height is satisfactory under the most typical sea states of between 0.5 m and 4 m [
33
].
However, while ERA5 is widely respected for its accuracy, it is not perfect. Its resolu-
tion may not be high enough to capture all local weather phenomena, especially those that
occur at smaller scales than ERA5 grid-size data, such as severe wind gusts. Additionally,
reanalysis data are based on both observations and model simulations, which means they
can sometimes contain inaccuracies or biases. Experimental or direct measurements are
often more accurate at capturing localised and extreme weather events.
Solar 2023,3420
3. Methodology
Our aim is to provide a comprehensive resource assessment of maritime floating
PV systems, taking account of wind speeds, wave heights, protected waters, distance
from land, and territorial considerations. We evaluated global ocean surface wind and
wave characteristics from 60 degrees North to 60 degrees South using hundreds of
thousands of 0.1-degree latitude and longitude cells, which is about 11 km
×
11 km at
the equator.
Hourly wind speeds and individual maximum wave heights were derived from
40 years (1980–2020) of ECMWF-ERA5 reanalysis data. The wind speed data is arranged
in an 11 km
×
11 km grid format. The u-component and v-component of wind speeds
at 10 m above water level, representing the horizontal speed of air moving eastward and
northwards, respectively, were obtained. Wind speed was calculated hourly using the
formula in Figure 3, with the maximum value selected for each hour.
Solar 2023, 3, FOR PEER REVIEW 5
means they can sometimes contain inaccuracies or biases. Experimental or direct meas-
urements are often more accurate at capturing localised and extreme weather events.
3. Methodology
Our aim is to provide a comprehensive resource assessment of maritime floating PV
systems, taking account of wind speeds, wave heights, protected waters, distance from
land, and territorial considerations. We evaluated global ocean surface wind and wave
characteristics from 60 degrees North to 60 degrees South using hundreds of thousands
of 0.1-degree latitude and longitude cells, which is about 11 km × 11 km at the equator.
Hourly wind speeds and individual maximum wave heights were derived from 40
years (1980–2020) of ECMWF-ERA5 reanalysis data. The wind speed data is arranged in
an 11 km × 11 km grid format. The u-component and v-component of wind speeds at 10
m above water level, representing the horizontal speed of air moving eastward and north-
wards, respectively, were obtained. Wind speed was calculated hourly using the formula
in Figure 3, with the maximum value selected for each hour.
Figure 3. Formula of wind speed calculation redrawn from ECMWF’s image [34].
Maximum individual wave heights, estimates of the highest wave within a 20 min
time window, were derived from the ECMWF-ERA5 reanalysis data [35]. The maximum
hourly wave height data in metres was classified into five ranges: 0–4, 4–6, 6–8, 8–10, and
>10. The maximum wind speeds, in metres per second, were classified into five ranges: 0–
5, 5–10, 10–15, 15–20, and >20.
These data were then combined at the nearest wind speed and wave height grid point
for each sea location and visualised using QGIS to create a wind–wave map, focusing on
maximum rather than average wave heights and wind speeds.
Tropical storms (cyclones, hurricanes, and typhoons) are likely to cause extensive
damage to maritime FPV systems that are not protected by expensive engineering de-
fences. We used 40 years of data (1980–2020) from the International Best Track Archive
for Climate Stewardship (IBTrACS) [36–39] to overlay the area of the sea impacted by
tropical storms. The main storm belts are illustrated in Figure 4. This comprehensive
global collection of tropical storms, provided by the National Center for Environmental
Information [40], helped identify areas that have experienced storms and are therefore
considered to be less suitable for FPV.
Figure 3. Formula of wind speed calculation redrawn from ECMWF’s image [34].
Maximum individual wave heights, estimates of the highest wave within a 20 min
time window, were derived from the ECMWF-ERA5 reanalysis data [
35
]. The maximum
hourly wave height data in metres was classified into five ranges: 0–4, 4–6, 6–8, 8–10, and
>10. The maximum wind speeds, in metres per second, were classified into five ranges: 0–5,
5–10, 10–15, 15–20, and >20.
These data were then combined at the nearest wind speed and wave height grid point
for each sea location and visualised using QGIS to create a wind–wave map, focusing on
maximum rather than average wave heights and wind speeds.
Tropical storms (cyclones, hurricanes, and typhoons) are likely to cause extensive
damage to maritime FPV systems that are not protected by expensive engineering defences.
We used 40 years of data (1980–2020) from the International Best Track Archive for Climate
Stewardship (IBTrACS) [
36
–
39
] to overlay the area of the sea impacted by tropical storms.
The main storm belts are illustrated in Figure 4. This comprehensive global collection
of tropical storms, provided by the National Center for Environmental Information [
40
],
helped identify areas that have experienced storms and are therefore considered to be less
suitable for FPV.
Maritime locations were attributed to countries based on the 200 nautical mile limit
from their coastlines using the EEZ shapefile provided by the Flanders Marine Institute [
42
],
in accordance with international maritime law. Protected marine and coastal areas were
removed from consideration using the May 2023 release of the World Database on Protected
Areas (WDPA) [
43
]. Figure 5shows an overview of the methodologies implemented in this
research.
Solar 2023,3421
Solar 2023, 3, FOR PEER REVIEW 6
Figure 4. Major tracks and frequency of hurricanes and typhoons. Image from Encylopedia Britan-
nica [41].
Maritime locations were attributed to countries based on the 200 nautical mile limit
from their coastlines using the EEZ shapefile provided by the Flanders Marine Institute
[42], in accordance with international maritime law. Protected marine and coastal areas
were removed from consideration using the May 2023 release of the World Database on
Protected Areas (WDPA) [43]. Figure 5 shows an overview of the methodologies imple-
mented in this research.
Figure 5. Flowchart of site assessments of offshore FPV sites.
4. Results and Discussion
Most of the world’s maritime areas have experienced waves larger than 10 m and
wind speeds larger than 20 m/s at sometime over the past 40 years. However, some re-
gions have not, and these became the focus of our study. Our study focused on five main
areas: the seas of Southeast Asia (I); the Red Sea and Persian Gulf (II); the Mediterranean
Figure 4.
Major tracks and frequency of hurricanes and typhoons. Image from Encylopedia Britan-
nica [41].
Solar 2023, 3, FOR PEER REVIEW 6
Figure 4. Major tracks and frequency of hurricanes and typhoons. Image from Encylopedia Britan-
nica [41].
Maritime locations were attributed to countries based on the 200 nautical mile limit
from their coastlines using the EEZ shapefile provided by the Flanders Marine Institute
[42], in accordance with international maritime law. Protected marine and coastal areas
were removed from consideration using the May 2023 release of the World Database on
Protected Areas (WDPA) [43]. Figure 5 shows an overview of the methodologies imple-
mented in this research.
Figure 5. Flowchart of site assessments of offshore FPV sites.
4. Results and Discussion
Most of the world’s maritime areas have experienced waves larger than 10 m and
wind speeds larger than 20 m/s at sometime over the past 40 years. However, some re-
gions have not, and these became the focus of our study. Our study focused on five main
areas: the seas of Southeast Asia (I); the Red Sea and Persian Gulf (II); the Mediterranean
Figure 5. Flowchart of site assessments of offshore FPV sites.
4. Results and Discussion
Most of the world’s maritime areas have experienced waves larger than 10 m and
wind speeds larger than 20 m/s at sometime over the past 40 years. However, some regions
have not, and these became the focus of our study. Our study focused on five main areas:
the seas of Southeast Asia (I); the Red Sea and Persian Gulf (II); the Mediterranean and
Black Seas (III); equatorial Africa (IV); and South America (V); as shown in Figure 6. Also
included in Figure 6are historical tropical storm tracks (represented by red lines).
Solar 2023,3422
Solar 2023, 3, FOR PEER REVIEW 7
and Black Seas (III); equatorial Africa (IV); and South America (V); as shown in Figure 6.
Also included in Figure 6 are historical tropical storm tracks (represented by red lines).
Figure 6. Five selected area of analysis avoiding historical storm paths: the seas of Southeast Asia
(I); the Red Sea and Persian Gulf (II); the Mediterranean and Black Seas (III); equatorial Africa (IV);
and South America (V)
Generally, the most suitable maritime regions for floating PV systems are located in
equatorial countries due to their relatively low winds and small waves. Such areas can be
found in the seas around Africa and Southeast Asia. Despite its equatorial location, north-
ern South America experiences larger waves than other equatorial regions.
The global mapping of wind and wave conditions in these areas is illustrated in Fig-
ure 7, while Table 1 summarizes the global maritime floating solar PV potential. Subse-
quent figures show individual regions in greater detail. In the figures, a heat map colour
key is used (Table 1). Red areas are best (calmer) followed by orange, yellow, and green,
while blue areas are the stormiest. Pale blue corresponds to maritime areas far from land
that were not considered in this analysis. Purple areas represent marine protected areas.
The dark gray line shows the history of tropical storms.
(a)
W
in
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
are a
Figure 6.
Five selected area of analysis avoiding historical storm paths: the seas of Southeast Asia (I);
the Red Sea and Persian Gulf (II); the Mediterranean and Black Seas (III); equatorial Africa (IV); and
South America (V).
Generally, the most suitable maritime regions for floating PV systems are located in
equatorial countries due to their relatively low winds and small waves. Such areas can
be found in the seas around Africa and Southeast Asia. Despite its equatorial location,
northern South America experiences larger waves than other equatorial regions.
The global mapping of wind and wave conditions in these areas is illustrated in Fig-
ure 7, while Table 1summarizes the global maritime floating solar PV potential. Subsequent
figures show individual regions in greater detail. In the figures, a heat map colour key is
used (Table 1). Red areas are best (calmer) followed by orange, yellow, and green, while
blue areas are the stormiest. Pale blue corresponds to maritime areas far from land that
were not considered in this analysis. Purple areas represent marine protected areas. The
dark gray line shows the history of tropical storms.
Solar 2023, 3, FOR PEER REVIEW 7
and Black Seas (III); equatorial Africa (IV); and South America (V); as shown in Figure 6.
Also included in Figure 6 are historical tropical storm tracks (represented by red lines).
Figure 6. Five selected area of analysis avoiding historical storm paths: the seas of Southeast Asia
(I); the Red Sea and Persian Gulf (II); the Mediterranean and Black Seas (III); equatorial Africa (IV);
and South America (V)
Generally, the most suitable maritime regions for floating PV systems are located in
equatorial countries due to their relatively low winds and small waves. Such areas can be
found in the seas around Africa and Southeast Asia. Despite its equatorial location, north-
ern South America experiences larger waves than other equatorial regions.
The global mapping of wind and wave conditions in these areas is illustrated in Fig-
ure 7, while Table 1 summarizes the global maritime floating solar PV potential. Subse-
quent figures show individual regions in greater detail. In the figures, a heat map colour
key is used (Table 1). Red areas are best (calmer) followed by orange, yellow, and green,
while blue areas are the stormiest. Pale blue corresponds to maritime areas far from land
that were not considered in this analysis. Purple areas represent marine protected areas.
The dark gray line shows the history of tropical storms.
(a)
W
in
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
are a
Figure 7. Cont.
Solar 2023,3423
Solar 2023, 3, FOR PEER REVIEW 8
(b)
(c)
Figure 7. World’s maritime: (a) maximum wind speed, (b) maximum wave height, (c) combined
maximum wind speed and wave height. Detailed map can be accessed at
http://re100.eng.anu.edu.au/ (accessed on 21 July 2023) (Supplementary Materials).
Table 1. Global maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5-10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m
0.1 171 669 8
- 0.02 34 134 2
0.03 45 176 2
4–6 m
139 2767 123
4 - 28 553 25
37 727 32
6–8 m
214 4050 1851 27
- 43 810 370
56 1092 513
8–10 m
0.4 493 2147 147
- 0.1 99 429
0.1 129 564
>10 m - 1 57 2216 7538
W
av e
h
e
i
g
h
t0 - 4
m
4 - 6
m
6 - 8m 8 - 10
m
> 10
m
P
ro tec te
d
are a
Figure 7.
World’s maritime: (
a
) maximum wind speed, (
b
) maximum wave height, (
c
) combined
maximum wind speed and wave height. Detailed map can be accessed at http://re100.eng.anu.edu.
au/ (accessed on 21 July 2023) (Supplementary Materials).
Table 1. Global maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m
0.1 171 669 8
-
0.02 34 134 2
0.03 45 176 2
4–6 m
139 2767 123
4
- 28 553 25
37 727 32
6–8 m
214 4050 1851 27
- 43 810 370
56 1092 513
8–10 m
0.4 493 2147 147
- 0.1 99 429
0.1 129 564
>10 m - 1 57 2216 7538
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar power (TW);
and (iii) potential annual solar generation (thousands of TWh per annum).
Solar 2023,3424
4.1. Southeast Asia (Region I)
The world’s most suitable region for maritime floating PV systems is in Southeast Asia.
Malaysia, Singapore, Brunei Darussalam, Papua New Guinea, and Indonesia possess large
potential for the deployment of floating PV technology. Notably, Indonesia possesses very
large areas of calm sea in and around the islands, as discussed in our previous work [
44
].
Indonesia is the world’s only large tropical archipelago.
Figure 8depicts the potential of the Southeast Asian maritime area for floating PV. The
figure shows that ideal locations for deploying floating panels are abundant throughout
Indonesian territory. Based on historical data on tropical storms over the past 40 years [
36
],
we found that the maritime region extending from the southern part of Indonesia to
northern Australia frequently experiences intense tropical storms. A similar situation is
observed in the northern part of Indonesia, the Philippines, Thailand, Vietnam, and regions
further north.
Table 2(and subsequent tables) provides a compilation of results for each of the
25 combinations of maximum wind speeds and wave heights. The areas analysed include
regions within 200 nautical miles (370 km) of the coast and exclude protected areas. The
three numbers within each cell are (from top to bottom): (i) the area (in thousands of km
2
);
(ii) the potential solar power (in TW); and (iii) the potential annual solar generation (in
thousands of TWh). For simplicity, we assume that solar panels have low (10 degree) tilt
and are densely packed to yield 0.2 GW of solar power per km
2
. We apply a capacity
factor according to an approximate average [
7
] for each region for low-tilt panels—in this
case 15%—to calculate potential annual energy yield. Dark blue cells (>10 m wave height,
>20 m/s wind speed) are not included in these calculations.
The numbers in each cell are necessarily approximate. The purpose is to provide
perspective. As noted in the introduction, an affluent society drawing all its energy from
solar PV may require around 20 MWh per person per year, which amounts to 1000 TWh
per 50 million people. Thus, the number 39 in the cell (<4 m, 5–10 m/s) is sufficient for
2 billion affluent people. The combined population of the relevant countries (Malaysia,
Singapore, Brunei Darussalam, Papua New Guinea, and Indonesia) is 0.33 billion people.
Indeed, Southeast Asia has 800,000 km
2
of seascape that, in 40 years, has not experi-
enced waves larger than 4 m or winds stronger than 15 m/s. This could generate about
210,000 TWh of electricity per year. This is sufficient for solar energy to provide the full
energy requirements of 10 billion affluent people, which is equivalent to the projected
global population in 2050. Any perception that these countries will have difficulty meeting
their future energy needs from solar energy without severe conflict with food production
and ecosystems is misplaced.
Solar 2023, 3, FOR PEER REVIEW 9
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar
power (TW); and (iii) potential annual solar generation (thousands of TWh per annum).
4.1. Southeast Asia (Region I)
The world’s most suitable region for maritime floating PV systems is in Southeast
Asia. Malaysia, Singapore, Brunei Darussalam, Papua New Guinea, and Indonesia pos-
sess large potential for the deployment of floating PV technology. Notably, Indonesia pos-
sesses very large areas of calm sea in and around the islands, as discussed in our previous
work [44]. Indonesia is the world’s only large tropical archipelago.
Figure 8 depicts the potential of the Southeast Asian maritime area for floating PV.
The figure shows that ideal locations for deploying floating panels are abundant through-
out Indonesian territory. Based on historical data on tropical storms over the past 40 years
[36], we found that the maritime region extending from the southern part of Indonesia to
northern Australia frequently experiences intense tropical storms. A similar situation is
observed in the northern part of Indonesia, the Philippines, Thailand, Vietnam, and re-
gions further north.
Table 2 (and subsequent tables) provides a compilation of results for each of the 25
combinations of maximum wind speeds and wave heights. The areas analysed include
regions within 200 nautical miles (370 km) of the coast and exclude protected areas. The
three numbers within each cell are (from top to bottom): (i) the area (in thousands of km
2
);
(ii) the potential solar power (in TW); and (iii) the potential annual solar generation (in
thousands of TWh). For simplicity, we assume that solar panels have low (10 degree) tilt
and are densely packed to yield 0.2 GW of solar power per km
2
. We apply a capacity factor
according to an approximate average [7] for each region for low-tilt panels—in this case
15%—to calculate potential annual energy yield. Dark blue cells (>10 m wave height,
>20m/s wind speed) are not included in these calculations.
The numbers in each cell are necessarily approximate. The purpose is to provide per-
spective. As noted in the introduction, an affluent society drawing all its energy from solar
PV may require around 20 MWh per person per year, which amounts to 1000 TWh per 50
million people. Thus, the number 39 in the cell (<4 m, 5–10 m/s) is sufficient for 2 billion
affluent people. The combined population of the relevant countries (Malaysia, Singapore,
Brunei Darussalam, Papua New Guinea, and Indonesia) is 0.33 billion people.
Indeed, Southeast Asia has 800,000 km
2
of seascape that, in 40 years, has not experi-
enced waves larger than 4 m or winds stronger than 15 m/s. This could generate about
210,000 TWh of electricity per year. This is sufficient for solar energy to provide the full
energy requirements of 10 billion affluent people, which is equivalent to the projected
global population in 2050. Any perception that these countries will have difficulty meet-
ing their future energy needs from solar energy without severe conflict with food produc-
tion and ecosystems is misplaced.
(a)
Wi
n
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
area
Figure 8. Cont.
Solar 2023,3425
Solar 2023, 3, FOR PEER REVIEW 10
(b)
(c)
Figure 8. Southeast Asia’s maritime: (a) maximum wind speed, (b) maximum wave height, (c) com-
bined maximum wind speed and wave height.
W
av e
h
e
i
g
h
t0 - 4 m 4 - 6m 6 - 8m 8 - 10m > 10m
P
ro tec te
d
area
Figure 8.
Southeast Asia’s maritime: (
a
) maximum wind speed, (
b
) maximum wave height, (
c
) com-
bined maximum wind speed and wave height.
Table 2. Southeast Asia’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m
0.1 149 650 6
-
0.02 30 130 1
0.03 39 171 1
4–6 m -
29 1776 95
3
6 355 19
8 467 25
6–8 m -
3 2115 1145 19
1 423 229
1 556 301
8–10 m -
172 1211 11
- 34 242
45 318
>10 m - - - 482 624
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar power (TW);
and (iii) potential annual solar generation (thousands of TWh per annum).
4.2. The Middle East (Region II)
The Red Sea and Persian Gulf have not experienced tropical storms. The Persian Gulf,
enclosed by several Middle Eastern countries, covers an area of about 241,000 km
2
[
45
].
The Red Sea, situated between Africa and Asia, has a surface area of approximately
Solar 2023,3426
450,000 km
2
[
46
]. Most of the Red Sea experiences maximum wind speeds in the range of
10–15 m/s. In the Persian Gulf, about half of the area exhibits maximum wind speeds of
10–15 m/s, while the remaining half reaches wind speeds of 15–20 m/s. The entire surface
of the Red Sea has a maximum wave height of 6–8 m, like most of the Persian Gulf, except
for a minor portion that records a maximum wave height of 8–10 m. Overall, both regions
typically experience maximum individual wave heights below 8 m and maximum wind
speeds below 15 m/s, as represented by Figure 9and Table 3. The maritime regions of the
Gulf of Aden, situated between Yemen and Somalia, as well as the southern Arabian Sea
near Oman, regularly experience storms.
Solar 2023, 3, FOR PEER REVIEW 12
(a)
(b)
Wi
n
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
area
W
av e
h
e
i
g
h
t0 - 4 m 4 - 6m 6 - 8m 8 - 10m > 10m
P
ro tec te
d
area
Figure 9. Cont.
Solar 2023,3427
Solar 2023, 3, FOR PEER REVIEW 13
(c)
Figure 9. The Red Sea and Persian Gulf’s maritime: (a) maximum wind speed, (b) maximum wave
height, (c) combined maximum wind speed and wave height.
Table 3. Red Sea and Persian Gulf’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m -
2 318 329
- 0 64 66
1 112 115
8–10 m - -
0.1 25
- 0.02 5
0.03 9
>10 m - - - - -
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar
power (TW); and (iii) potential annual solar generation (thousands of TWh per annum).
4.3. The Mediterranean and Black Sea (Region III)
The Mediterranean Sea and the Black Sea are located at the southern edge of Europe,
which has a high population density and a northerly latitude. It would be advantageous
if substantial capacity for floating PV were available to supplement land-based PV and
the immense offshore wind resources in the North, Irish, and Baltic Seas.
Nearly all areas of the Mediterranean and Black Seas experience large waves of more
than 10 m, although tropical storms do not penetrate this far north. Protected regions such
as the northern Adriatic and the Greek Isles, as shown by Figure 10, offer scope for floating
PV systems that have engineering defences sufficient to withstand waves up to 10 m in
height. About 29,000 TWh per annum (Table 4) could be generated in such systems if they
could also survive wind speeds of up to 20 m/s (assuming a capacity factor of 14%). Such
systems would need to compete economically with land-based PV in southern Europe
and northern Africa.
Figure 9.
The Red Sea and Persian Gulf’s maritime: (
a
) maximum wind speed, (
b
) maximum wave
height, (c) combined maximum wind speed and wave height.
Table 3. Red Sea and Persian Gulf’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m -
2 318 329
-
0 64 66
1 112 115
8–10 m - -
0.1 25
-
0.02 5
0.03 9
>10 m - - ---
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar power (TW);
and (iii) potential annual solar generation (thousands of TWh per annum).
The Arabian Peninsula has excellent wind and solar resources, and so it is questionable
whether floating PV in the Red Sea or Persian Gulf will be required.
4.3. The Mediterranean and Black Sea (Region III)
The Mediterranean Sea and the Black Sea are located at the southern edge of Europe,
which has a high population density and a northerly latitude. It would be advantageous if
substantial capacity for floating PV were available to supplement land-based PV and the
immense offshore wind resources in the North, Irish, and Baltic Seas.
Nearly all areas of the Mediterranean and Black Seas experience large waves of more
than 10 m, although tropical storms do not penetrate this far north. Protected regions such
as the northern Adriatic and the Greek Isles, as shown by Figure 10, offer scope for floating
PV systems that have engineering defences sufficient to withstand waves up to 10 m in
height. About 29,000 TWh per annum (Table 4) could be generated in such systems if they
could also survive wind speeds of up to 20 m/s (assuming a capacity factor of 14%). Such
systems would need to compete economically with land-based PV in southern Europe and
northern Africa.
Solar 2023,3428
Solar 2023, 3, FOR PEER REVIEW 14
(a)
(b)
(c)
Figure 10. The Mediterranean and Black Sea’s maritime: (a) maximum wind speed, (b) maximum
wave height, (c) combined maximum wind speed and wave height.
Table 4. Mediterranean and Black Sea’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m - - - - -
8–10 m
0.4 11 106 69
- 0.07 2 21
0.1 3 26
>10 m - 0.4 16 500 2,079
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar
power (TW); and (iii) potential annual solar generation (thousands of TWh per annum).
4.4. Africa (Region IV)
Equatorial Africa has enormous scope for floating PV (Table 5). There is potential for
11,000 TWh of floating solar generation from regions that do not experience waves larger
than 4 m in height or winds stronger than 15 m/s (Figure 11). This is enough for 550 million
affluent people—about one third of Africa’s current population. If the tolerable maximum
wave height is 6m, then the available resource increases to 300,000 TWh per annum, which
Wi
n
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
area
W
ave
h
e
i
g
h
t0 - 4 m 4 - 6m 6 - 8m 8 - 10m > 10m
P
ro tec te
d
area
Figure 10.
The Mediterranean and Black Sea’s maritime: (
a
) maximum wind speed, (
b
) maximum
wave height, (c) combined maximum wind speed and wave height.
Table 4. Mediterranean and Black Sea’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m - - - - -
8–10 m
0.4 11 106 69
- 0.07 2 21
0.1 3 26
>10 m - 0.4 16 500 2079
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar power (TW);
and (iii) potential annual solar generation (thousands of TWh per annum).
4.4. Africa (Region IV)
Equatorial Africa has enormous scope for floating PV (Table 5). There is potential for
11,000 TWh of floating solar generation from regions that do not experience waves larger
than 4 m in height or winds stronger than 15 m/s (Figure 11). This is enough for 550 million
affluent people—about one third of Africa’s current population. If the tolerable maximum
wave height is 6 m, then the available resource increases to 300,000 TWh per annum, which
is enough for 15 billion affluent people. It is notable that the open sea in the Gulf of Guinea
does not experience large waves.
Solar 2023,3429
Floating PV has the potential to reduce land use conflicts. Countries bordering the
Gulf of Guinea are experiencing large population growth rates. Nigeria is projected to
reach 377 million people in 2050 [
47
] and become the world’s third most populous country.
It already has one of the highest population densities [
48
] in Africa, at 250 people per km
2
.
In 2050, 377 million affluent Nigerians could generate 7500 TWh per annum, sufficient for
all their energy needs, from 6 TW of floating PV covering 30,000 km
2
of Nigeria’s territorial
seas.
Solar 2023, 3, FOR PEER REVIEW 15
is enough for 15 billion affluent people. It is notable that the open sea in the Gulf of Guinea
does not experience large waves.
Floating PV has the potential to reduce land use conflicts. Countries bordering the
Gulf of Guinea are experiencing large population growth rates. Nigeria is projected to
reach 377 million people in 2050 [47] and become the world’s third most populous coun-
try. It already has one of the highest population densities [48] in Africa, at 250 people per
km
2
. In 2050, 377 million affluent Nigerians could generate 7500 TWh per annum, suffi-
cient for all their energy needs, from 6 TW of floating PV covering 30,000 km
2
of Nigeria’s
territorial seas.
(a) (b) (c)
Figure 11. Africa’s maritime: (a) maximum wind speed, (b) maximum wave height, (c) combined
maximum wind speed and wave height.
Table 5. Africa’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m
23 19 2
5 4 0
6 5 1
4–6 m
110 991 29
0
22 198 6
29 260 8
6–8 m
209 1617 271 7
42 323 54
55 425 71
8–10 m
310 804 67
62 161
81 211
>10 m - - 13 1224 4794
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar
power (TW); and (iii) potential annual solar generation (thousands of TWh per annum).
4.5. South America (Region V)
The northern half of South America experiences gentle winds; about 28 thousand km
2
of seascape does not experience winds stronger than 15 m/s (Table 6). However, Central
America is subject to frequent tropical storms, while almost the entire South American
coastline is subject to large waves (>10 m), as shown in Figure 12. Offshore floating PV in
Central and South America is unlikely to be an economical proposition because of the
need for extensive and expensive engineering defences.
W
ave
h
eig
h
t0 - 4 m 4 - 6m 6 - 8m 8 - 10m > 10m
Wi
n
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
area
Figure 11.
Africa’s maritime: (
a
) maximum wind speed, (
b
) maximum wave height, (
c
) combined
maximum wind speed and wave height.
Table 5. Africa’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m
23 19 2
540
651
4–6 m
110 991 29
0
22 198 6
29 260 8
6–8 m
209 1617 271 7
42 323 54
55 425 71
8–10 m
310 804 67
62 161
81 211
>10 m - - 13 1224 4794
Note: In each cell, the numbers are (top to bottom): (i) area (thousands of km
2
); (ii) potential solar power (TW);
and (iii) potential annual solar generation (thousands of TWh per annum).
4.5. South America (Region V)
The northern half of South America experiences gentle winds; about 28 thousand km
2
of seascape does not experience winds stronger than 15 m/s (Table 6). However, Central
America is subject to frequent tropical storms, while almost the entire South American
coastline is subject to large waves (>10 m), as shown in Figure 12. Offshore floating PV in
Central and South America is unlikely to be an economical proposition because of the need
for extensive and expensive engineering defences.
Solar 2023,3430
Solar 2023, 3, FOR PEER REVIEW 16
(a) (b) (c)
Figure 12. South America’s maritime: (a) maximum wind speed, (b) maximum wave height, (c)
combined maximum wind speed and wave height.
Table 6. South America’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m - - - - -
8–10 m - - - - -
>10 m - 0.5 27 10 42
Note: In each cell, the numbers are available area (thousands of km
2
).
5. Conclusions
A global assessment of suitable maritime areas for the installation of offshore floating
PV systems has been conducted, considering maximum wind speeds, maximum wave
heights, protected areas, and territorial considerations. Maximum wave height and wind
speeds over 40 years (1980–2020) were utilised.
Most of the global seascape experiences waves larger than 10m and winds stronger
than 20 m/s. The engineering defences required for floating PV under such conditions may
render them uneconomic compared with land-based solar and wind turbines (both on-
shore and offshore). However, in some areas, offshore floating PV is potentially an im-
portant component of a 100% renewable energy future.
The most prospective regions cluster within 5–12 degrees of latitude of the equator,
principally in and around the Indonesian archipelago and in the Gulf of Guinea in the
vicinity of Nigeria and neighbouring countries. These regions have low potential for wind
generation, high population density, rapid growth in both population and energy con-
sumption, and substantial intact ecosystems that should not be cleared for solar farms.
The economical scope for offshore floating PV in Central and South America is lim-
ited by tropical storms and large waves. The Middle East has large technical potential,
although there will be strong competition from land-based solar and wind farms. Europe
has some prospects in sheltered areas, such as the northern Adriatic Sea and around the
Greek Isles.
The combined offshore floating solar PV annual generation potential for regions that
do not experience waves larger than 4m or winds stronger than 15 m/s is 220,000 TWh.
This is sufficient for all the energy needs of an affluent global population of 11 billion
W
ave
h
eig
h
t0 - 4 m 4 - 6m 6 - 8m 8 - 10m > 10m
W
in
d
spee
d
0 - 5 m/s 5-10m/s 10 - 15m/s 15 - 20m/s > 20m/s
P
ro tec te
d
area
Figure 12.
South America’s maritime: (
a
) maximum wind speed, (
b
) maximum wave height, (
c
) com-
bined maximum wind speed and wave height.
Table 6. South America’s maritime floating solar PV potential.
Wave Height Wind Speed
0–5 m/s 5–10 m/s 10–15 m/s 15–20 m/s >20 m/s
0–4 m - - - - -
4–6 m - - - - -
6–8 m - - - - -
8–10 m - - - - -
>10 m - 0.5 27 10 42
Note: In each cell, the numbers are available area (thousands of km2).
5. Conclusions
A global assessment of suitable maritime areas for the installation of offshore floating
PV systems has been conducted, considering maximum wind speeds, maximum wave
heights, protected areas, and territorial considerations. Maximum wave height and wind
speeds over 40 years (1980–2020) were utilised.
Most of the global seascape experiences waves larger than 10 m and winds stronger
than 20 m/s. The engineering defences required for floating PV under such conditions may
render them uneconomic compared with land-based solar and wind turbines (both onshore
and offshore). However, in some areas, offshore floating PV is potentially an important
component of a 100% renewable energy future.
The most prospective regions cluster within 5–12 degrees of latitude of the equator,
principally in and around the Indonesian archipelago and in the Gulf of Guinea in the
vicinity of Nigeria and neighbouring countries. These regions have low potential for
wind generation, high population density, rapid growth in both population and energy
consumption, and substantial intact ecosystems that should not be cleared for solar farms.
The economical scope for offshore floating PV in Central and South America is limited
by tropical storms and large waves. The Middle East has large technical potential, although
there will be strong competition from land-based solar and wind farms. Europe has some
prospects in sheltered areas, such as the northern Adriatic Sea and around the Greek Isles.
The combined offshore floating solar PV annual generation potential for regions that
do not experience waves larger than 4 m or winds stronger than 15 m/s is 220,000 TWh. This
Solar 2023,3431
is sufficient for all the energy needs of an affluent global population of 11 billion people.
If maximum wave heights of 6 m can be tolerated, then the annual energy generation
potential rises to about one million TWh as an upper bound.
The analysis and conclusions presented in this paper depend on the accuracy of
meteorological reanalysis. Further work is required to ensure that the ERA5 data really
does capture the historically largest waves and strongest winds. Additionally, tsunamis
could be a significant risk in some areas. Finally, some maritime areas may be excluded
because of their impact on fishing, navigation, the expansion of protected areas, and other
factors.
Supplementary Materials:
Map details can be accessed at https://re100.eng.anu.edu.au/ (accessed
on 21 July 2023).
Author Contributions:
Conceptualisation, D.F.S. and A.B.; data curation, D.F.S.; formal analysis,
D.F.S.; methodology, D.F.S. and A.B.; supervision, A.B.; validation, A.B.; visualisation, D.F.S.; writing—
original draft, D.F.S.; writing—review and editing, A.B. All authors have read and agreed to the
published version of the manuscript.
Funding:
The APC was funded by the Australian National University. D.F.S.’s ongoing PhD study is
funded by the Indonesia Endowment Fund for Education (LPDP).
Institutional Review Board Statement: Not applicable.
Informed Consent Statement: Not applicable.
Data Availability Statement: Not applicable.
Acknowledgments:
D.F.S.’s ongoing PhD study is funded by the Indonesia Endowment Fund for
Education (LPDP).
Conflicts of Interest: The authors declare no conflict of interest.
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