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Historic and recent progress in solar chimney power plant enhancing technologies
... The use of a porous medium is one of the many strategies that researchers have developed to increase efficiency and store energy. In solar systems, porous materials are typically used as the method (Al-Kayiem and Aja, 2016). Numerous studies have used porous absorbers because of their larger interface area and higher heat transfer coefficients. ...
... Rashidi et al. (2017) produced an outstanding performance review on porous media used in solar energy systems. These materials absorb more solar energy and promote natural ventilation (Al-Kayiem and Aja, 2016;Zheng et al., 2010). Porous media applications in solar energy systems have drawn a lot of interest. ...
... One of the numerous methods that scientists have created to boost productivity and store energy is the application of porous media. Porous materials are commonly employed as the approach in solar systems (Al-Kayiem and Aja, 2016). Because of their higher heat transfer coefficients and bigger interface area, porous absorbers have been used in many investigations. ...
... Most of th studies mainly describe the basic principles, advantages, and disadvantages of SCPP [14][15][16][17]. Some studies explore geometric modifications to enhance the performance o SCPPs [18][19][20], while others propose innovative designs [15,21]. Optimization throug energy and exergy analyses has been investigated by [22], while cost analysis has bee explored by Al-Kayiem and Aja [21] and Pradhan et al. [19]. ...
... Some studies explore geometric modifications to enhance the performance o SCPPs [18][19][20], while others propose innovative designs [15,21]. Optimization throug energy and exergy analyses has been investigated by [22], while cost analysis has bee explored by Al-Kayiem and Aja [21] and Pradhan et al. [19]. Hybridization of SCPPs ha also been reviewed in the current study [23,24] to achieve improved performance. ...
... Most of the studies mainly describe the basic principles, advantages, and disadvantages of SCPPs [14][15][16][17]. Some studies explore geometric modifications to enhance the performance of SCPPs [18][19][20], while others propose innovative designs [15,21]. Optimization through energy and exergy analyses has been investigated by [22], while cost analysis has been explored by Al-Kayiem and Aja [21] and Pradhan et al. [19]. ...
Solar chimney power plants (SCPPs) are encouraging sustainable energy sources due to their low cost, abundance, low maintenance, and eco-friendliness. However, despite significant efforts to optimize SCPP design, their efficiency and power generation capabilities remain limited. Researchers have explored modifications in plant geometry and hybridization to improve efficiency. Despite extensive work in this area, commercialization of SCPPs has not yet been achieved. Most of the research is numerical and may differ from real-world practical use. The number of experimental studies is also relatively small. To facilitate commercialization, further investigation with practical and feasible dimensions is required. This comprehensive review paper aims to provide an in-depth analysis of experimental approaches and advancements in the field of SCPPs. The paper begins with an introduction, highlighting the background, significance, and objectives of the review. It provides an overview of the plants, discussing their principles and operation as innovative renewable energy systems. The historical development and evolution of solar chimneys are explored, shedding light on their progression over time. Case studies of operational hybrid SCPPs are examined to showcase real-world applications and performance. The paper also addresses environmental impacts and sustainability considerations associated with SCPPs. Furthermore, recommendations for future research and development in this field are provided to guide researchers and industry professionals. This study focuses on the possibility of commercialization of both standalone and hybrid SCPPs.
... Several solar thermal technologies such as dish-Stirling [3], parabolic trough collector [4], linear Fresnel system [5], solar tower [6] have already been considered for various microgrid studies and have proved to be efficient because of their flexible design and maximum record for solar to electric energy alteration. In the proposed work, a novel solar chimney [7,8] along with a combined solar gas turbine [9] has been used. A realistic microgrid with wind solar and biogas plant has been built by considering a group of villages that meets their energy requirement and supplies the excess energy to the neighboring microgrid [10]. ...
... A solar chimney (SC) uses solar energy which upsurges the internal energy of air flowing through the system [7]. It comprises three parts: (i) solar collector, (ii) chimney, (iii) a power conversion unit [26]. ...
... The working condition of the SC power plant involves absorbing the energy from the sun using an exposed solar air accumulator to warm up the air [7]. It is an amalgamation of an open solar air collector and a chimney to produce the flow of air which instigates the wind turbine to produce electrical energy. ...
The article assesses the frequency control of a dual area hybrid microgrid (DHM) that comprises solar thermal systems alongside biodiesel-powered generators, energy storage components, and DC link. The chaotic butterfly optimization (CBOA) technique is used to attain the tuned gain constraints of the cascaded PI-TID controller. The novelty of the system lies in the integration of a combined solar gas turbine and solar chimney for load frequency control studies. Also, the application of CBOA to tune the controllers of cascaded PI-TID controllers is a novel approach. The superiority of CBOA tuned PI-TID controller is obtained after performing a comparative analysis of PID, TID, and PI-TID for controller selection and PSO, SCA, BOA, and CBOA for selecting the superior algorithm. The outcome of each component of the system is analyzed and subjected to the consideration of different real-time scenarios. Sensitivity evaluation is carried out by altering the source and load settings to establish the domination of the CBOA optimized PI-TID controller.
... Adrar city of Algeria having a monthly power potential of 140 to 200 kW over the year. The progress and advancement in the area of SUT technologies were reviewed by Al-Kayiem et al. [14]. In this study, authors presented the outlook and global energy scenario and also disclosed the potential of solar energy for power generation application. ...
... A detailed discussion on hybrid models and innovations was included to improve the system performance. Though various reviews try to discuss the scientific contributions in the field [14][15][16], this specific topic needs to be reviewed more by considering the aspect of commercialization. If it is commercialized, it can produce a surplus amount of electrical energy without much maintenance cost as the moving parts involved in the plant are less. ...
... First prototype of SUT plant at Manzanares, Spain[14], (with permission from Elsevier). ...
In the 21st century, utilization of solar energy takes a new peak due to the increase in global energy demand, environmental concerns and scarcity of fossil fuel. Among various technologies, the solar updraft tower plant generates intensive interest among researchers in recent years. Remarkably advancements in the plant were achieved over the decades through various numerical, analytical and experimental studies. In this review work, the thermodynamic principle behind the plant and energy balance equations needed for different components were reviewed as these are useful for design calculations. Also, exergy analysis and cost estimation were discussed. The worldwide status of the plant in the last two decades was reviewed and observed that the power potential of the system was in the range of 0.053–27 MW. The summary of each mathematical analysis and research gaps were reported as these are useful for future studies. The factors affecting the performance of the plant such as surface transfer coefficients, pressure profile and turbine pressure drop were also reported. Lower thermal efficiency, land requirements for commercial plant and building tall chimney were the major challenges on the plant which are also discussed. Lastly, the recommendations and future perspective of the plant is outlooked.
... Moreover, the review articles give a collection of past research works published in the area of solar chimneys. Some of the review articles also discussed the systematic [20]. A few articles also discussed flow physics, numerical methods, exergy and energy analysis, and also challenges and opportunities in conventional SUT plant technology [21][22][23][24]. ...
... It can be further reduced by including the revenue generated from carbon credits over its service life. At present, the LEC of different solar powered technologies including SUT is far Al-Kayiem and Aja [20] • The appraisal of the global energy and demand • Review on SUT plant investors, discussion on SUT plant, its components, performance, and cost modeling ...
... The core premise of solar energy harvesting systems is similar. They function on the basis of absorbing solar radiation passing through a darkened absorber surface when the absorbent system surface and the working fluid are in direct or indirect contact [4] [5]. The aim of this article is to evaluate the performance of a novel system within an IPV/solar chimney under Iraqi weather conditions. ...
... The kinetic power of the system was calculated using eq (8). Figure 1 shows the kinetic Power variation (5). The kinetic power rates increased in August due to an increase in solar radiation [22], with the highest kinetic energy of 56 W reported at 1 p.m. in August. ...
the aim of paper includes evaluating the performance of a proposed design of a Photovoltaic Solar chimney. in this design the solar cells are fixed in the mid-distance between the chimney base and the glass cover. therfore, the air can move over and below the solar cells to accelerate the Photovoltaic cells cooling and obtain the air s' high velocity. the result showed that the Photovoltaic cells location determines its temperature, where high temperature s characterstic the solar panels in the middle. the solar panels on the ends, on the other Hand, were at a lower temperature. in addition, the temperature of the solar panels is affected by the weather due to the low temperatures of the solar cells troughout the monthly test, optimum efficiency values were observed in the early morning. May-electrical efficiency value was 13.9% for APril. In contrast, main-electrical efficiency was 11.5% in August at 1 p. m. the highest recorder thermal efficiency values were 58.9% for August at 1 p. m
... Other hybrid systems include combining SC with agriculture, food drying and building ventilation [23e25], which broaden the applications of SC greatly. Due to the high cost and the difficulty of large-scale commercial system construction, hybrid SC systems are not common, and the comprehensive development needs to be further explored [26,27]. ...
... The daily heat exchange in nighttime hours Q n can be calculated based on the heat released by the ground at night: Q n ¼ r g A c d g c pg Dt ag (27) according to Table 1, Q n is 5.13 Â 10 12 J. Taking the power generation efficiency of SC in nighttime hours as 0.15%, the power generation E n is about 2138 kWh. ...
Due to fossil fuel shortage and high carbon emissions, more and more inefficient coal-fired power plants are being decommissioned. Many redundant resources like chimneys and electric equipment are thus left behind, which can be combined with renewable energy for transformation. Therefore, a hybrid photovoltaic/solar chimney (PV/SC) power plant combined with agriculture is proposed to transform a decommissioned thermal power plant in Ningxia, China. The collector canopy is partially covered with PV modules and simultaneously serves as an agricultural greenhouse for planting activities. Meanwhile, the hot air flow under the canopy can be integrated with air source heat pumps (ASHPs) for domestic heating. Detailed mathematical models are developed to investigate power generation and heat collection performance. The economic and environmental benefits are quantitatively evaluated. The results show that the average daily power generation capacity of PV and SC can reach 334.2 MWh and 9.3 MWh, respectively. The total power generation capacity increases by 5.98% compared with an equivalent single PV power plant. The annual CO2 emission reduction can be up to 1.27 × 10⁶ tons, and the total annual revenue is more than $ 5.47 million. The transformed plant has an impressive comprehensive solar energy conversion efficiency of 14.2% considering power generation, agricultural production and heating, which is 36.9% higher than that of an equivalent conventional PV power plant. The proposed plant has a power generation capacity of 343.5 MWh/d and can bring about notable economic and environmental benefits, which are of great significance to the transition of renewable energy and achieving lower carbon emissions. This work can provide a feasible reference for the upgrading of industries with high pollution and low efficiency.
... • Intensifying inventions in solar chimney technology: The growing number of patents and publications provides opportunities for innovation in SCPPs [157]. • Immense potential and growing awareness: In hot and humid climates, technology has enormous potential. ...
... Hybrid and different systems are interpreted. [157] Historic and recent progress in solar chimney power plant enhancing technologies ...
This research presents a comprehensive review of solar chimney power plants (SCPP) as a reliable source of renewable electricity generation. Solar chimney power plants differ from other renewable energy technologies because thermal and momentum effects result in 24-h electricity generation. However, they are influenced by a wide range of design, geometrical and operational parameters, and environmental conditions. This review evaluates the design aspects and the theoretical, numerical, experimental, and performance findings in previous works holistically and concisely. The study also extensively discusses the various optimization strategies, advantages, disadvantages, and limitations of solar chimney power plants. Energy storage aspects and hybrid system designs are also addressed in the present review in order to overcome the known handicaps and limitations of solar chimney power plants. The performance figures of the technology are clearly demonstrated as a function of the design and operational conditions, and future prospects are discussed in detail. It is hoped that designers and policymakers will gain valuable insight into the technological features and advancements of solar chimney power plants, assisting them in making a better-informed decision.
... Energy infrastructure is at the heart of this dilemma, serving as a point of convergence for a wide range of policy objectives ranging from economic growth and national security to climate change mitigation and social inequity [1]. As the energy demand increases in the world a surge in the demand for small and more efficient energy systems is seen, notably within the realm of wind energy [2]. Many researchers contributed to this pursuit and introduced systems that can help in achieving high efficiency. ...
With the escalating demand for energy, there is a growing focus on decentralized, small-scale energy infrastructure. The success of new turbines in this context is notable. However, many of these turbines do not follow many of the basic ideas established to evaluate their performance, leaving no precise technique or mathematical model. This research developed a Ducted Horizontal-axis Helical Wind Turbine (DHAHWT). The DHAHWT is a duct-mounted helical savonius turbine with a venturi and diffuser to improve flow. Unlike a vertical axis helical savonius turbine, DHAHWT revolves roughly parallel to the wind, making it a horizontal turbine. This complicates mathematical and theoretical analysis. This study created a DHAHWT mathematical model. COMSOL simulations utilizing Menter’s Shear Stress Transport model (SST) across an incoming velocity range of 1m/s to 4m/s were used to evaluate the turbine’s interaction with the wind. MATLAB was used to train an artificial neural network (ANN) utilizing COMSOL data to obtain greater velocity data. The Mean Average Percentage Error (MAPE) and Root Mean Square Error (RMSE) of ANN data were found to be 3%, indicating high accuracy. Further, using advanced statistical methods the Pearson’s correlation coefficient was calculated resulting in a better understanding of the relationship of between incoming velocity and velocity at different sections of the wind turbine. This study will shed light on the aerodynamics and working of DHAHWT.
... The first SCPP pilot plant, which was built in 1980s generated approximately 200 MW of electricity (Schlaich, 1981;Ghalamchi et al., 2017). Comprising a chimney tower, a turbine, and a solar collector (Al-Kayiem and Aja, 2016), the SCPP functions by utilizing solar energy to heat the air, altering its physical properties (pressure, enthalpy, and momentum), increasing kinetic and thermal energy of the air, leading it to ascend in the chimney and force the turbine blades, converting mechanical energy into electrical energy (Pasumarthi and Sherif, 1998). ...
Globally, countries are strategically devising and implementing plans for hydrogen production, recognizing its status as the future's primary energy fuel. This study, conducted in Irbid, Jordan, serves as a case study focusing on producing green hydrogen by integrating a Solar Chimney Power Plant (SCPP) with a nuclear power plant (NPP). The innovative design of the proposed SCPP involves the incorporation of a water pool and an electrolyzer station, facilitating the production of desalinated water, green hydrogen, and oxygen, and leveraging the excess waste heat generated by the NPP to enhance the overall system performance. The proposed integration directly routes the excess hot air from the NPP tower into the SCPP's collector to enhance the temperature profile under the collector and the air velocity, boosting electricity and water production. This integration demonstrated a significant improvement over the conventional SCPP. Specifically, the SCPP+ NPP system produced 716 MWh/year, surpassing the traditional SCPP's output of 362 MWh/year. Furthermore, the proposed design exhibited substantial gains in freshwater production, yielding approximately 260,000 tons/year compared to the conventional SCPP's 140,000 tons/year. Ratio analysis indicates a positive correlation between integrated electricity generation and water output, emphasizing the sustained improvement in water production (average ratio ~1.88) in the SCPP+NPP system. The proposed SCPP+NPP not only doubled its green hydrogen output, reaching 25 tons/ year compared to the conventional SCPP's 13 tons/year, but also contributed a substantial 200 tons/ year of oxygen, surpassing the traditional SCPP's 100 tons/ year. The results underscored the superior performance of the proposed SCPP+ NPP across various metrics—hydrogen production, electricity generation, freshwater yield, and oxygen output—exhibiting a twofold improvement over the conventional SCPP. Consequently, implementing the integration between SCPP and NPP, emerges as a promising and viable solution for green hydrogen production in Jordan.
... 6 simulations and modeling, although the hybrid solar chimney-desalination system has great potential and can maximize performance, it is still a research phase. Solar chimney plants have not had major demonstrations and have been produced intermittently with no improvement in performance, there are several projects internationally, for example, the 1500m high chimney system planned for South Africa, a 200 MW plant in China, three more 200 MW projects in the USA and a 200 MW solar chimney plant in China [49], these have only been planned and have not been built, although they promise to meet the necessary scales and better performance, taking into account that the stacks would have to have relatively low capital and investment delivery prices [50] 2.6. Combined system with renewable energy Renewable energies are intended to provide a solution to the problems mentioned above, by integrating desalination systems with renewable energy sources, which are divided into two types: ...
Increasing global demand for water and energy has given rise to renewable energies that offer an environmentally friendly alternative. Solar desalination systems have become a very attractive topic, due to the fact that areas lacking fresh water have a wealth of solar energy, allowing to present a convenient, promising and viable solution, also obtaining drinking water for consumption in remote areas from water with high salinity, where it is considered to be a process free of CO 2 emissions when powered by solar radiation, being sustainable and environmentally friendly. The main objective of this study is to provide an extensive review of the different solar desalination systems, evaluating the indicators, factors and technologies involved in the process, through scientific sources such as: articles, academic publications, international congresses, indexed journals, and others.
... Subsequent studies sought to address the inherent low efficiency and the challenges associated with the scale of the collector and chimney through a plethora of experimental, computational, and mathematical approaches. Comprehensive reviews have synthesized advancements in SCPP technology, as in Chikere et al. [1], Al-Kayiem and Chikere [2], Kasaeian et al. [3], and more recent analyses of hybrid systems by Ahmed et al. [4], and evaluations of SCPP concepts and performance by Cuce et al. [5]. ...
The present study examines a solar chimney power generation model under tropical conditions, with a focus on the impact of ground absorber dimensions on system efficacy. An experimental and numerical analysis was conducted using a 15-meter-high solar chimney, where the ground was transformed into a sensible thermal energy storage system through the application of black-painted pebbles. Three configurations were assessed to determine system performance: Case-1 and Case-2, featuring collector diameters of 4.9 m and 6.6 m, respectively, and Case-3, which introduces an innovative design extending the diameter of the sensible thermal energy storage (TES) by 2.0 m beyond the collector's canopy. Performance was gauged using a metric defined by the product of mass flow rate and temperature increase of the air. Numerical models were validated against experimental outcomes, with results showing a satisfactory correlation. It was found that the performance metric in Case-2 doubled, while in Case-3, it tripled relative to Case-1. The enhancement in performance in Case-3 was further evidenced by a 30.4% increase in air velocity at the chimney base over Case-2, and a 36.7% increase over Case-1, highlighting the efficacy of the extended sensible TES. These findings suggest that enlarging the TES area beyond the collector's canopy can significantly improve solar chimney performance, potentially enabling a reduction in construction scale and a concurrent decrease in electricity production costs. This approach represents a promising avenue for addressing the dual challenges of structural height and efficiency that currently hamper the feasibility of solar chimney power generation on an industrial scale.
... In order to optimize the consumption of solar energy and address the aforementioned constraints pertaining to standalone solar updraft tower power plants, the notion of hybridization has emerged as an efficient approach for solar chimney power plants [61]. Numerous efforts have been made by researchers to boost the performance of conventional standalone solar chimney power systems with the integration of various energy conversion technologies. ...
In a previous work, a solar chimney power plant integrated with a solid sorption cooling system for power and cold cogeneration was developed. This prior work showed that reusing the heat released from the adsorption bed enhances the system’s utilization of solar energy and increases the turbine’s output power. In the present paper, a subsequent modification to the arrangement and operation of the preceding system is introduced. The primary objective of the modification is to enhance performance and increase the plant’s capacity to effectively harness the available solar radiation. The method involves placing the condenser tubes at the solar collector entrance. Therefore, the airflow captures the condenser-released heat before it enters the collector. The modified configuration and operation of the system are discussed. A dynamic mathematical model is established to simulate the hybrid system’s operation and evaluate its parameters. The obtained results show that a 5.95% increase in output power can be achieved by recovering the heat of condensation. Furthermore, the modified system attains a 6% increase in solar-to-electricity conversion efficiency compared with the basic system. The findings suggest that the modified system, which recycles condenser heat, provides noticeable enhanced performance compared with the basic system.
... The experimental data of the Manzanares power plant, as the first medium-scale SCPP with research application, is the most cited experimental data in this technology field, which has been used in a wide range of studies [29,51,[60][61][62][63]. Design data, environmental conditions, and performance results have been collected and published by Haaf et al. [5,7]. ...
Solar Chimney Power Plants (SCPP) are among the promising solar thermal electricity generation technologies. Equipped with a Thermal Energy Storage (TES) system, such technologies can overcome variations in the main driving factors such as solar radiation and ambient air temperature. This article presents a comprehensive semi-analytical model of a TES to predict the time-dependent performance of an SCPP. By introducing a Quality Factor of power generation (QF) that includes energy conversion efficiency and capacity factor, the effects of 15 TES materials have been studied on the plant performance. Results indicate no significant difference between water TES and clay or soil type, and water-filled bags or tubes are relatively ineffective in improving performance compared to them. Among the various TES materials analyzed, a type of wet soil, i.e., the specific wet mixture of clay, sand, and silt in closed and dark-colored bags, shows excellent performance in both QF enhancement and having low Heat Penetration Depth (HPD) simultaneously. The QF and HPD are directly affected by thermal effusivity and thermal diffusivity, respectively. Implementing wet soil TES for the studied power plant (Man-zanares) enhances the QF from 7.46 % (for limestone soil) to 10.95 %. Water-filled bags demonstrate a heat penetration depth of 0.4 m, while wet soil exhibits a slightly greater depth of 0.5 m. Furthermore, water-filled bags experience a broader temperature range of 40 C, whereas wet soil undergoes a comparatively smaller temperature variation of 26 C. Furthermore, the capacity factor rises from 41.18 % to 61.07 % when utilizing wet soil TES compared to water-filled bags.
... T IJSER ISSN 2229-5518 IJSER © 2016 http://www.ijser.org Solar chimney is heat energy conversion system which cinsit of three technologies that is collector,Turbine and chimney.It works on the principle which involves absorption heat of sun rays using solar air collector to heat air inside.The heated air rises due to density differance from inlet to outlet of collector.Chimney is supported in collector by using quadrilateral connector whch provide air tight joint between collector and chimney.At the chimney base Turbine is located which sense this density variation and high pressure airdraft inside the collector.Turbine converts the kinetic energy of air into electricity when it is get coupled to the Generator [16].The working principle of solar chimney power plant is shown in fig.1. ...
A solar chimney power plant which can provide off-grid electricity in central region of India particularly in Vidarbha region is studied in this paper. The regions like Amravati and Nagpur have high temperature in the range of 40 to 50 0 c in summer but still there is a loads heading of 10 to12 hours because of lack of solar to electrical energy conversion sources in large extent. In this paper data of small scale solar chimney model which fabricated for experimental and analysis purpose is presented which has collector of 1.8 m diameter and maximum chimney height of 2 m.The parameters such as temperature,velocity,and density are considered for study. The maximum value of velocity recorded was 1.4 m/m.The variation of velocity is higher as compared to other process parameters.
... The wind turbine is usually installed at the bottom of the chimney. Suggestions have also been made to use multiple vertical axis turbines at the bottom of the chimney or multiple horizontal axis turbines under the solar collector canopy and surrounding the chimney [1]. ...
The solar vortex engine (SVE) aims to replace the tall and expensive chimney structure in solar updraft power plants by a shorter less expensive structure named the vortex generator. In this study, the entire SVE system is simulated by CFD to determine the appropriate location for the turbine unit as well as prove the capability of the vortex generator in replacing the chimney. Three different cases for the SVE are considered and compared to corresponding cases of the solar chimney power plant (SCPP). Results revealed that the optimum turbine location is at the outlet hole of the vortex generator. An updraft air velocity of 1.82 m/s was achieved at the outlet hole, compared to 1.56 m/s at the base of a solar chimney with the same diameter as the upper hole. The consideration of the turbine pressure drop did not affect the formation and preservation of the air vortex. So, the 1 m high vortex generator successfully replaced the 8.6 m chimney component in solar updraft power plants, greatly reducing the cost and construction complexity of the plant. The vortex generator accelerated the air delivered from the solar collector, increasing its velocity by 14 times. The SVE's power output is directly proportional to the static pressure drop across the turbine. The mean difference values along the air vortex field between the cases with and without a turbine are 0.67 Pa and 0.026 m/s for the static pressure drop and velocity magnitude, respectively.
... A solar chimney power plant can operate under widespread sun radiation, can be durable and requires little upkeep. The concept of the SCPP consists of heating the air between the tower chimney's transparent cover and its base [70]. The hot air trapped between the glass cover and the absorbent floor as a result of its high temperature and low efficiency will move upwards, and due to the airflow, the wind turbines installed in the lower part of the tower chimney will rotate. ...
... It was determined that cooling medium such as fins are required. The fins are a crucial aspect of the development of absorbent elements to accomplish the PV/T hybrid's high-power thermal and electrical efficiency [9][10][11][12] . Reda etal. ...
Photovoltaic Cells are devices made of semiconductor materials that is used to convert solar energy to electrical energy in the form of a constant current. The efficiency of the photovoltaic cell increases with the increase in solar radiation while its generation efficiency decreases with the increase in Photovoltaic Cell temperature above the standard temperature. Therefore, researchers implement methods to decrease overheating. One of these methods is using PV/T. This paper presents an experimental and numerical study on the performance of the Photovoltaic/Thermal (PV/T) system by using Nanofluids with a new design (novelty; sphere fins in open flow flat collector) of the water collector. Experiments were carried out in Iraq/Baghdad/University of Technology. Nanofluids Al2O3/water was used at different volume concentration ratio as 1%, 2%, and 3% for cooling of PV panel. The influence of new design of collector and Nano additives on the PV/T performance at various operational parameters have been simulated and evaluated using ANSYS Fluent software to solved the Navier-Stockes and energy equations. Numerical results noticed a decrease in the surface temperature of the collector by 5.1% when using a Nano liquid with a concentration 1% compared to its temperature when using water only, while it decreases by 6.2% and 7.8% when using concentrations 2% and 3%, respectively at flow rate 3.5 l/min. The evaluation result demonstrates that the performance of PV/T system increased, also the Nanoparticles helped to system enhances.
... Research within the context of using an SUTPP has considered tower modification, the collecting unit having thermal storage [23], the effect of wind [24], variations in glazing [25,26] and its slop [27] for extended operational hours, the modification of the PCU to increase power output [28,29], and cost modeling; other fields of research have focused on interaction with the atmosphere, ecology, agriculture, socio-economics, alterations to the basic concept, and technological development. Many studies in these areas have been conducted by various researchers and scholars [30][31][32][33]. ...
This study investigates the possibility of applying a large-scale solar updraft tower power plant in India with local ground conditions as an environmentally friendly and economically viable energy source. A reference model Solar Updraft Tower Power Plant (SUTPP) is constructed to examine the influence of the most prominent plant dimensional parameters, including collector radius (RCollector), tower height (HTower), and tower radius (RTower) with dimensional limits and intervals on the power output of the SUTPP. Udat, Rajasthan, India, is used as a reference location for meteorological conditions to evaluate SUTPP power output equations for a ranging power output, with position coordinates of 27°35′ and 72°43′. Multiple simulations for the objective function are carried out, and the outcomes are compared to the optimized dimensions of each set of plants. The model examines the effect of variation in ambient, plant geometry, and material conditions on power output and analyzes efficiency and power output for optimizing configuration. There exists no definitive approach to determining the proper correlation between the geometrical parameters of a SUTPP with optimized power output. For a fixed power output, the tower radius (RTower) serves as the most influencing dimensional parameter in SUTPP performance. A change in tower height (HTower) has a detrimental impact on SUTPP output and performance. An initial increase in collector radius (RCol-lector) has a positive influence on SUTPP performance; however, this effect reduces as collector radius (RCollector) increases.
... This treatment produces fresh sludge where decomposed by anaerobic bacteria and resulting in a condition of liquidity for a few days before turning into semi-solid slurry. Sludge generated every year due to the rapid growth of population and development due to urbanization life [1]. ...
Sewage industry have generated huge amount of sewage sludge. It is found that the amount of sewage sludge generated by Malaysia sewerage companies has reached 5.3 million m3 per year. Sewage sludge (SS) are usually disposed into a landfill or incineration but due to the huge amount of sludge produced and limited availability of lad, it has become an environmental hazard. Thus, this research was conducted to utilize sludge that resulted from the wastewater treatment plant into fired clay brick as well as contributed to other alternative disposal method for the sludge. This research focuses on the investigation of indoor air quality of fired clay brick incorporating with SS. The SS was collected from IWK located at Senggarang and Perwira whilst clay soil was collected at Yong Peng, Johor. The characteristics of SS and clay soil were analyzed using X-ray fluorescence (XRF). From the results, it showed that SS was high with silicon oxide (SiO2) and zinc (Zn) that makes it compatible to replace clay soil as raw materials. Next, two types of sewage sludge brick (SSB) which are Senggarang brick (SB) and Perwira brick (PB) were incorporated with 0%, 1%, 5%, 10% and 20% of SS respectively. Then, the compressive strength test was conducted in accordance with the British Standard BS 3921: 1985. Based on the result, it shows that 5% of SS replacements as clay soil into fired clay brick have achieved the optimum strength. As for the indoor air quality (IAQ) test were done in walk-in stability chamber (WiSC) and the gas emission was compared with the Industry Code of Practice on Indoor Air Quality (ICOP-IAQ) through Department of Occupational Safety and Health Malaysia (DOSH, 2010). From the result, IAQ brick for SB and PB showed that up to 5% in fired clay brick were complied with the standard which below the acceptable limit that has provided for wall, column and cube formed. Thus, as a conclusion this method provided an alternative disposal method for the SS whilst producing a new low-cost building material with no negative effect to human as well as benefit to the environment.
... Then, the hot air ascends through the chimney, where the solar energy stored in the hot draft air is converted into mechanical and electrical energy by an electricity-generating turbine. The operational principles and analysis of the solar chimney and development attempts are well presented and critiqued in many review papers, e.g., Kasaeian et al. [3] and Al-Kayiem and Chikere [4]. ...
A large percentage of solar energy is converted to accumulated thermal energy leading to temperature rise in the PV panel. The raised PV surface temperature could be utilized for fluid heating. The objective of the current work is to integrate the PV panels with an inclined solar chimney and carry out an experimental and numerical assessment of the developed hybrid system. An experimental model comprises a solar collector with a photovoltaic panel as an absorber, a chimney, and a convergent nozzle has been developed. A Series of measurements have been carried out at various weather conditions. A numerical simulation predicted the airflow and heat transfer characteristics utilizing ANSYS fluent software to extend the analysis and evaluation of the hybrid system. Results showed that the hybrid system produces power within a range of 9% to 11% efficiency, which is approximately two orders of magnitude higher than the typical solar chimney efficiency. In contrast, it increased by 18% compared to the stand-alone PV panel. A minor increase in output power with a negligible decrease in LCOE was expected to increase the size further.
... Solar chimneys were also used to ventilate and heat buildings and homes (Monghasemi and Vadiee, 2018;Zou et al., 2017). The solar chimney in Manzanares (Al-kayiem and Chikere, 2016;Kasaeian et al., 2017b), Spain, was one of the first solar chimneys built in the world (Fig. 2). The chimney's height is about 180 m, the diameter of the chimney is 5.08 m, and the radius of the collector was 122 m with a PVC roof cover. ...
The global interest in solar energy as an alternative to traditional fuels has led to a significant overall increase of attentiveness to solar energy systems, especially the solar chimney system. Because one potential drawback of solar chimney systems is the low efficiency of more traditional solar chimneys, researchers and scientists are trying to improve the efficiency of the solar chimney system by integrating them with other conventional or renewable energy systems called hybrid solar chimneys. The current review article examines solar chimney systems combined with other renewable or conventional energy systems. The emphasis of this article was placed on compact solar chimneys with solar panels, solar ponds, and geothermal energy, in addition to a presentation on some solar chimney systems integrated with power stations. These hybrid solar chimneys are described, quantifying the improvement in efficiency, identifying future challenges, and providing insights to researchers on designs that have been introduced in recent years. Suggestions have been submitted to develop the performance of hybrid solar chimneys.
... Many parameters influence the performance of the collector, including the materials of the collector's transparent cover, place of the power plant, collector slope, environmental conditions, and solar radiation access. Solar Air Collector (SAC) takes up almost 50% of the Solar Chimney Power Plant (SCPP) investment and accounts for 50% of system loss [2]. Enhancement of this section may make SCPP investment economical, attractive, and competitive. ...
In this study, a three-dimensional hybrid solar chimney with an integrated external thermal source is developed to complements the solar energy for uninterruptible power generation using flue gas channels as a supply source in the collector. The hybrid system is examined numerically using ANSYS Fluent software including a solar air collector with a diameter of 6 meters, a 6.65-meter-long chimney, and four thermal channels. The timetable is set for different hours, namely for two modes, i.e. without flue gas during daytime (1st Case), with flue gas during daytime (Case 2-A), and with flue gas during night (Case 2-B). Moreover, the turbine effect in different day hours and with different heat sources during night are applied. The numerical method is validated by comparing its results with previous works based on different chimney heights. The present results show that the hybrid approach increases system performance significantly. Simulation is done in thermal channel with 0.0015 kg/s in chimney temperature of 116 C. The results indicate that mass flow rate and power increased by 7.63% and 11.48%, respectively, compared to the mode with no flue gas. This study proved that the proposed method can eliminate the night defect and allow the operation of solar chimney power plants at night.
... The present equivalent cost C pe of AMC is given in (4), where i is the interest rate, f is the inflation rate, C om is the O&M cost at the end of first year and N is the expected project lifetime. The interest rate is assumed as 10%, inflation rate is taken as 6% [36,37] and project lifetime, N is considered as 25 years for each system ...
This chapter discusses the assessment of comprehensive technoeconomic performance by simulation and experimental values over a 1-year period for four distinct solar photovoltaic (PV) systems mounted at the Indian Institute of Technology Kharagpur in West Bengal, India. The chapter includes the field system description and their user interface followed by detailed modeling of PV, inverters, and the sun tracking (ST) systems in MATLAB/Simulink. It then explains the evaluation of the overall system performance for all four configurations using technical performance indices (energy yield, capacity factor, performance ratio) and economical performance indices (payback period, net present value, levelized cost of energy) defined by IEC Standard 61724. The impact of inverter technology and ST system is thoroughly discussed using the field data of one full seasonal variation. The technical dominance of Dual Axis Micro Inverter-based solar PV system and economical superiority of Dual Axis String Inverter-based solar PV system over other configurations is validated through simulation and experimental field results.
... Then, the hot air ascends through the chimney, where the solar energy stored in the hot draft air is converted into mechanical and electrical energy by an electricity-generating turbine. The operational principles and analysis of the solar chimney and development attempts are well presented and critiqued in many review papers, e.g., Kasaeian et al. [3] and Al-Kayiem and Chikere [4]. ...
... Abro et al. (2019) presented how modern technology has been researching on the mentioned methods for desalination and pure water extraction and desalination with high efficiency yet at a low cost. Using solar chimney prototypes for several research and businesses have suggested in (Al-Kayiem and Aja, 2015). While the proposed system displayed an efficiency of less than 2%, and designated a promising technology that converted and harnessed solar energy into electric power and saline water into freshwater. ...
Increasing water demand and the deteriorating environment has continuously stressed the requirement for new technology and methods to attain optimized use of resources and desalination management, converting seawater into pure drinking water. In this age, the Internet of Things use allows us to optimize a series of previously complicated processes to perform and required enormous resources. One of these is optimizing the management of water treatment. This research presents an implementable water treatment model and suggests smart environment that can control water treatment plants. The proposed system gathers data and analysing to provide the most efficient approach for water desalination operations. The desalination framework integrates smart enabling technologies such as Cloud Portal, Network communication, Internet of Things, Sensors powered by solar energy with ancient water purification as part of seawater's desalination project. The proposed framework incorporates the new-age technologies, which are essential for efficient and effective operations of desalination systems. The implemented desalination dual membrane framework uses solar energy for purifying saline water using ancient methods to produce clean water for drinking and irrigation. The desalination produced 0.47 m3/l of freshwater from a saline concentration of 10 g/l, consuming 8.31 KWh/m3 energy for production from the prototype implementation, which makes desalination process cost effective.
... Schematic view of SCPP[4]. ...
The solar updraft tower system is a renewable-energy technology which convert solar energy to electric power. The system consists of three main parts ; solar collector, updraft tower (chimney) , and wind turbine(s). The current study is aims to estimate the thermal performance of hybrid solar updraft tower by installing PV panel(s) in different positions within .The experimental model was built for this purpose in Al-Kut city-Iraq with geometrical dimensions consist of chimney (6 m in height and 0.3 m in diameter) made of PVC, collector (6 m in diameter and 0.1 m height at the outer edge with 20 o inclination). The experimental work was carried out on different days from August to October 2019. The results include that the PV panel(s) can be installed at a different location within the system without significantly effect on the thermal performance. While installing the PV panel on the glass at the collector outlet influences the thermal performance significantly due to the shading area occurred at the important zone within the SCPP system (collector-chimney convergence zone). Consequently, the air velocity difference (enhancement) between this case and the others is (11.46%). On the other hand, the power produced from PV panel(s) installed in a different location is identical for all locations except for the ground location, which is low capacity compared to the other (Power generation enhancement is 136.3% as compared with other location) due to heating the panel because of the high ground temperature and zero panel inclination. So that, the favorable location for installing the PV panel within the SCPP to reach the optimum overall performance will be the firstly at the chimney, surface of collector inlet, the surface of collector outlet and last location is at the ground. Finally, the hybrid technique (SCPP with PV panel(s) could be the optimum choice to get better overall performance without affecting the thermal performance of the conventional SCPP.
... However, materials such as receivers may be similar in shape but different in properties especially in terms of resistance to pressure, simplicity and cost [53]. This is because, whereas PTC has some level of control on the pressure which is generally lower due to indirect system employed, LFR work on high pressure due to DSG system employed, as such the receivers used must be able to withstand the high pressure that will be generated in the absorber tubes [54]. Similarly, PTC system requires two HTFs to be used as working fluids while LFR usually requires only 1fluid for operation. ...
Supply of energy in sufficient quantity and quality while sustaining the environment is one of the key strategies of human development adopted by most countries and the United Nations at large. This makes solar energy a strong candidate in achieving the aim of sustainable development goals and thus many countries launched several researches towards harnessing and utilisation of solar energy in different forms. Electricity generation using photovoltaic systems have over the years becomes the most successful applications of solar energy and solar thermal systems are also gaining grounds in many countries especially Spain and United States. With their variable designs with at least a design suiting any environment at variable cost, the potential for concentrated solar power development globally is high especially in areas with high solar insolation. Similarly, solar energy storage was reviewed visa-vis the challenges associated with it giving much emphasis on the thermal storage component. This paper also reviews the developments in the field of solar energy technology applications with reference to some case studies of some plants. Finally, the various policies employed through international bodies such as United Nations and some adopted by individual countries were highlighted. It was concluded that concentrated solar power is one of the promising renewable energy technologies that will meet the needs of man.
In this study, an experimental model of a photovoltaic (PV) solar chimney (SC) was built and study the extent to which the asphalt material, being a phase‐change material, affects its performance electrical and thermal. Results were taken for the two systems: The photovoltaic solar chimney which contains phase change material (SCPV‐PCM), and the photovoltaic solar chimney which does not contain phase change material (SCPV). The finding demonstrated that the PCM affects the SCPV electrical and thermal performance; the results were as follows: The electrical power for the SCPV‐PCM system increased during the day and its highest value at noon was 384.34 W, and then it began to decrease. The SCPV system had a higher power at the end of the test, 73.24 W, due to the lower temperature of the PV panel. The highest electrical efficiency was for the SCPV‐PCM system at the beginning of the test, reaching the highest value of 13.12%, then it decreased at the end of the test to be less than the SCPV system at 5:00 pm. The thermal efficiency of the SCPV‐PCM arrangement is lesser than the arrangement that does not contain PCM, reaching its highest value at noon, which was 57.1% for the SCPV system. The total efficiency of the SCPV‐PCM system is lesser than the SCPV system from the beginning of the test until 3:30 pm approximately, reaching its highest value of 68.05% at noon.
Solar thermal energy storage (TES) is a system that collects and stores thermal energy through heating or cooling in a storage medium. The stored energy can be used as the primary source later when there is no solar input. Solar TES is a promising approach to encourage the adoption of solar energy in a broader range, as it addresses the issue of interrupted solar processes for heating-cooling sources and power generation. Solar TES technologies are mainly used in buildings and commercial processes. This chapter discusses solar TES technologies, which assess solar energy and meet the energy demand of a building, particularly in hot regions. It explains the principle and calculation of the storage capacity of various solar thermal energy storage systems. Heat-sensitive storage technologies such as water tanks, underground storage, and packed-bed storage methods are briefly reviewed. Additionally, it explores a latent-heat storage system using phase-change materials for use in solar heating/cooling of buildings, solar water heating, heat-pump systems, and concentrating solar power plants, as well as thermochemical storage. Finally, it provides a brief review of cold thermal energy storage and includes new information on the efficiency and cost of solar TES systems.
This study presents an experimental investigation of the effect of different solar collector geometrical parameters on the solar vortex engine's (SVE) performance. The first parametric study is concerned with a solar vortex power generation system's diameter, inlet height, and thermal energy storage (TES) extension. The experimental results revealed that extending the TES by 1 m outside the canopy significantly increases thermal efficiency by 62%. In addition, increasing the diameter of the solar collector from 8.8 m to 10.8 m, with an extra 1 m extended TES area, increased the air temperature rise by 57%, while the outlet air velocity increased by 32%. On the other hand, a reduction in the collector inlet height from 0.2 m to 0.15 increased the air temperature rise while decreasing the outlet air velocity and power output potential by mean values of 19% and 48%, respectively. The enhancement obtained from the extended area of TES is an important finding, as it increased the air temperature for a larger canopy size without extra cost. Therefore, increasing the absorption area or the TES outside the canopy is recommended. Also, further studies are essential to correlate the inlet height to the system's performance.
Population growth, increase in energy demand, and environmental problems of fossil fuels have led to the use of renewable energies. One of the applications of solar energy is the solar chimney thermal power plant. Building a solar chimney is not cost-effective due to its low thermal efficiency, so studies have been conducted to increase its efficiency. Among the studies conducted, few have studied the influence of absorber geometry on system performance. In this research, the solar chimney was designed in small dimensions and effect of changing the geometry of the absorbent surface was investigated. The numerical model has been validated with experimental data of Manzanares pilot plant. The geometry was numerically simulated in Ansys Fluent software. Realizable k-ε model for turbulence and DO irradiation model for radiation has been used. The solar radiation 1000 \({W \mathord{\left/ {\vphantom {W {m^{2} }}} \right. \kern-0pt} {m^{2} }}\) is selected. The coupled arithmetic was used as the pressure–velocity coupling scheme. Besides, the discretization method for the pressure term was PRESTO! Algorithm while other terms were second-order. The criterion of convergence in solving all equations is \(10^{ - 6}\). The results showed that the maximum velocity for height 0.1 and 0.2 m has increased by 6.945% and 8.048%, respectively, compared to the smooth absorber surface. By increasing the height in the center of the solar chimney, the maximum power is obtained at a height of 0.2 m with a value of 2.338 w. Therefore, changing the geometry of the absorber affects the performance of the chimney and can strengthen it.
Urban air pollution has become a pressing challenge in recent times, demanding innovative solutions. This review delves into the potential of Solar Chimney Power Plants (SCPPs) as a sustainable approach to mitigating air pollution. The idea of mitigation of pollution may be an added advantage to the use of SCPPs in practice. Recent advancements, such as the integration of photocatalytic reactors (PCRs) for the elimination of greenhouse gases (GHGs), emphasizing the importance of addressing non-CO2 GHGs like CH4 and N2O are analyzed. The novelty of this review is that it not only focuses on the shifting and removal of particulate matter but also on the removal of greenhouse gases. Numerous case studies, ranging from filter-equipped SCPPs to Solar-Assisted Large-Scale Cleaning Systems (SALSCSs), are reviewed, providing a comprehensive understanding of their design, performance, and potential benefits. This review serves as a guide for researchers and policymakers, emphasizing the need for multifaceted approaches to address the intricate nexus of air pollution, renewable energy generation, and climate change mitigation.
The collector's periphery height determines the entrance size to the solar chimney power plant. There is inconsistency in the published experimental and numerical results on the optimum collector inlet height for different collector diameters. This paper aims to analyze the available data to identify the best collector inlet height-to-diameter ratio and to introduce a design guide for an optimized performance of solar chimney power plants. The experimental data reported in previous works have been clustered and manipulated to produce a comparative argument on the collector inlet height-to-diameter. In addition, a numerical model is developed to support the literature conclusions and to produce further data to decide the optimum collector inlet height-to-diameter ratio. For a 6.6-m collector diameter, four different inlets have been investigated, namely, 0.05, 0.1, 0.15, and 0.2 m. The best performance in terms of air velocity and temperature rise is obtained with the 0.05-m inlet height, where it shows an improvement of up to 35.35% compared to the larger inlet heights. The lower collector inlet height allows a more effective heat transfer from the ground and the collector to the air. It is concluded that the optimum collector inlet height-to-diameter design ratio for solar chimneys with collector diameters larger than 3 m is 0.0075±0.0005. For small-scale solar chimney models with less than 3 m collector diameter, the best collector inlet height-to-diameter ratio ranges between 0.015 and 0.03.
Global radiation is a significant input in the design and simulation of solar PV as well as low temperature solar thermal systems. Moreover, meteorological conditions of any location also greatly influence the design, simulation, and output of the solar energy system. The considerable importance of global radiation leads to a dire need for global radiation models in the lack of measurement. Consequently, to enhance the predictability of solar resources over India, models for global radiation simulation through meteorological parameters (temperature, relative humidity, and wind speed) are proposed. Data of nine stations from NASA for 10 years (2008–2017) are used in the study to calibrate the models and performance of developed models is assessed through different statistical indicators (MPE, MBE, RMSE, R ² , RMSD, NSE, and TS). The investigation reveals that out of the three proposed models, the model correlating total solar radiation with relative humidity, temperature, and wind speed is found to provide the highest accuracy in global radiation simulation with least statistical errors and is selected as best fit model. Moreover, validation of the proposed models is approved through monthly average daily total solar radiation predication for the remaining four testing cities of India and also through comparison with previously available models in the literature.
Nowadays, it is necessary to develop sustainable energy suppliers according to the concerning environmental issues. Solar energy is one of the appropriate solutions. Solar Chimney Power Plant (SCPP) represents a viable form of solar thermal electricity generation technology. Temporal variations in the driving factors of the plant, especially solar radiation, cause significant fluctuations in output power. This study evaluates active and passive control strategies for achieving more stable power generation in SCPP using Fuzzy Logic Control (FLC) and Thermal Energy Storage (TES) systems. The governing equations for performance modeling have been solved by a developed MATLAB code and validated with experimental data from the Manzanares prototype. Using TES reduced output power fluctuations and showed daily electrical energy generation of 331.9, 314.3, and 308.7 kWh for sand, limestone soil, and water-filled bags, respectively. Implementing an active control strategy with the FLC system alone provided a 25 and 30-kW baseload generation in the mid-hours of the day. Finally, integrating the FLC and TES systems in a hybrid control strategy continued a base load power generation of 12 and 16 kW up to 4 h after sunset, utilizing limestone soil and water-filled bags, respectively.
The work represents a unique methodology for control of frequency in three area independent and interconnected hybrid microgrid systems. The proposed hybrid microgrids consist of solar chimney (SC), combined solar gas turbine (CSGT), bio‐diesel operated generator (BDOG), DC link, energy storage units such as battery energy storage unit (BESU), super‐magnetic energy storage unit (SMESU), and redox flow battery (RFB) based. Integration of generating units such as SC, CSGT, BDOG, SMESU, RFB, and DC link in three area hybrid microgrid is also a unique work. A newly developed chaotic butterfly optimization algorithm (CBOA) is applied so as to obtain the optimized standards of the cascaded PI‐TID controller employed with dispatchable generating units. Comparative analysis of different algorithms and controllers is achieved to establish the dominance of the anticipated control strategy. The impact of each component on the system is examined while taking into account various real‐time scenarios. Finally, the efficacy of cascaded PI‐TID controller tuned using CBOA is established by sensitivity analysis with significant changes in source and load circumstances.
According to WorldVision, Eritrea has the least access to clean water in Africa. Therefore, this work presents a unique dual-technology power plant (DTPP) model for electricity and distilled water production as a potential solution to the clean water problem in Eritrea. The novel design of the DTPP consists of a solar chimney power plant (SCPP), operating in the daytime, and a cooling tower (CT), operating at nighttime, showing excellent performance improvement over the conventional SCPP. Based on the results, the DTPP produced ∼509,715 kWh of electrical energy annually, which is almost double the amount of energy generated (238,273 kWh) by the traditional SCPP. Additionally, the DTPP produced 189,867 tons of distilled water annually, which is 37% more, when compared to the SCPP. Furthermore, the electrical power produced can also be used to produce additional clean water using other desalination techniques. It was concluded that the DTPP could be a viable solution for the clean water shortage in Eritrea. A valuable recommendation can be optimizing the DTPP design specifically for water production tailored to the needs of Eritrea.
The generation of energy from renewable sources is dependent mostly on weather conditions because of which instabilities in the hybrid microgrid system may arise. To tackle the same in such a system, coordinated frequency and voltage control with appropriate control strategy have been investigated in this work considering a single area independent hybrid system. A combined solar gas turbine, solar chimney, and biodiesel-operated generator along with hybrid electric vehicles and refrigerators as the thermostatic load are used to model the hybrid system. Constraints of the proposed cascaded PI-TID controller are finely tuned with the recently developed DBOA. Coordinated frequency and voltage control of a combined solar gas turbine-solar chimney with thermostatic loads in an isolated hybrid microgrid system have not been reported earlier. Furthermore, the application of DBOA to tune a cascaded PI-TID controller for coordinated control of voltage and frequency is a novel approach. Extensive simulation studies of the model is carried out to obtain the dynamic response by considering various uncertain conditions. Values of maximum overshoot (0.002194), undershoot (0.006042), and setting time (1.781sec) of frequency deviation and peak overshoot (0.002296), undershoot (0.004511), and setting time (1.709 sec) of voltage deviation proved the effectiveness of the proposed system.
A solar-assisted large-scale cleaning system (SALSCS) is a solar thermal system that utilizes the concept of a solar chimney power plant (SCPP) to improve outdoor air quality. In an SALSCS, air purification is facilitated by passing the buoyancy-induced airflow through an air filter installed in the system. In the current study, a new solar chimney system called a filter-equipped SCPP (FSCPP), which is a hybrid of SCPP and SALSCS, is proposed and investigated to identify the possibility of generating electrical power and purifying outdoor air simultaneously. A three-dimensional numerical model is developed to study the heat transfer and fluid flow inside the solar chimney. The simulation method is implemented and validated with experimental data from the literature. The simulation results reveal that the pressure drop is higher across the filter than at the turbine in the FSCPP, indicating a higher energy consumption at the filter. Numerical simulations are also carried out to compare the performance of the SCPP, SALSCS and FSCPP. The results show that the FSCPP has the lowest volume flow rate and the highest temperature rise. The electrical power generated by the FSCPP is only about 20∼40% of the SCPP’s power generation, but its air purification capabilities approximate those of the SALSCS, with only a 2 to 4 % reduction. The influence of the system’s dimensions on overall system performance is also analyzed. The FSCPP shows an enhancement in primary capabilities (i.e., power generation and air purification) with an increase in the width and height of the solar chimney system of up to 200 meters.
Solar chimney power plant (SCPP) is one of the promising technologies to convert solar energy into carbon-free power generation. It has cost competitiveness, environment friendly and longer service life. Although remarkable advancements were achieved, commercialization aspect of the SCPP has not been established so far. Feasibility assessment of the large-scale plants was carried out by researchers in different climatic conditions across the globe but none of the studies materialized to date. However, it is almost four decades from the development of the first prototype, and no studies have been discussed the barriers to commercialization of the SCPP yet. Therefore, in this present study, a-state-of-the-art review has been presented which discussed the overview of SCPP technologies, factors affecting the flow and performance characteristics of the plant and major barriers in the commercialization aspect of the plant. The overview of SCPP technology including its global status and recent advances are spotlighted. The power potential and carbon emission mitigation of the SCPP based on the climatic condition and geographical location was studied by taking India as an example. In addition to that, the major challenges and opportunities in the SCPP are also addressed. Based on the analysis, a few recommendations are given for commercialization the plant.
The solar chimney (SC) was effectuated as a prototype by several engineers and scientists to utilize updraft solar heating. A solar chimney power plant (SCPP) heats the surrounding air using solar radiation when drives a wind turbine-generator unit to produce electrical power. The SCPP has enormous size, produces a remarkable amount of electricity, and thus, reduces the adverse environmental impacts. The dimensions of the SCCP components, such as collector area, the diameter and height of the chimney, etc., should be optimized to achieve the best performance from the energy and exergy points of view. Since exergy is consumed in the SCPP due to irreversibilities, there is a direct relation between exergy and SCPP development. This review paper describes different components of an SCPP, provides general governing equations, and presents mathematical models for energy and exergy analyses. Besides, advances in exergy analysis of SCPP are discussed and future directions are provided.
Libya is facing an increasing deficit in electrical energy supply which needs great efforts to find new and renewable alternative sources of power. Solar thermal electricity is one of the most promising and emerging renewable energy technologies to substitute conventional fossil fuel systems. A review of the research literature of solar thermal electricity in Libya is presented in this article. The state of the art of these technologies including design, operation principles, and the global market is demonstrated. Detailed reviews of research activities that have been conducted by Libyan researchers or institutions are presented. It has been found that Libya as a country needs a strategic plan and more research efforts in order to adopt these new technologies and put them in production mode.
The aim of the study is to get the best and the most efficient design of Solar Chimney Power Plant (SCPP) considering different chimney and collector parameters. SCPP is one of the most promising applications of solar energy because of the high reliability of the system in addition to the low cost of long-term energy production and low maintenance needs. Because of the reasons above, it has been a focus for researchers to increase efficiency of such systems. Solar chimney power plant is a thermal system containing three basic components; the solar collector, the solar chimney and the wind turbine.
SCPP has basic working principles which are the effect of greenhouse, chimney drag and conversion to kinetic energy. The air below the semi-transparent collector (glass) is heated up by the solar radiation which is coming from the top of the collector surface.
The heated air moves by buoyancy force to the center of the collector where the turbine is located. The heated air leads to a flow through the turbine and drives the turbine which rotates a generator and electric energy is obtained from that rotation. In this study, a 2-D computational fluid dynamics (CFD) analysis for the entire system of solar chimney power plant is done by using commercial program ANSYS 18.2.
After verifying the CFD results of the numerical model with the results of the experimental work and obtaining almost identical results, the main parameters like the height of tower, the diameter of the tower, the tower configuration, the diameter of the collector, the height of collector and the inclination angle of the collector which can effect on performance of SCPP has been changed and the influence of varying these parameters on the effectiveness and performance of the solar chimney system is studied. It is found through this study that all of the chimney and the collector parameters which are mentioned above have a direct impact on the effectiveness and performance of SCPP. Depending on the numerical results, it is found that the height and the diameter of the tower is considered as the most effective parameters which can affect largely on the value of the output power of SCPP and the height and diameter of chimney equal to 3.5 m and 25 cm are the best values considering the performance of the chimney. Also results shows that the diverging chimney configuration is the best tower geometry that can be utilized and it can improve and increase the performance of SCPP largely. The numerical findings shows that the increase of solar collector diameter leads to increasing the output power and the best value for the diameter of the collector is 400 cm (the maximum value). Furthermore, it is concluded that the height and inclination angle of the solar collector has an important effect on the output power and the best design for solar collector parameters is 6 cm height of the solar collector with 0 degree for the inclination angle of the solar collector.
Nowadays, solar energy is one of the mostly preferred renewable energy sources with low cost and no harmful emissions and is considered as one of the most promising alternatives to fossil fuels. Since the 1980s, one of the most beneficial applications of solar energy is the utilization of solar chimney power plants (SCPP). An SCPP is a simple and a reliable system which consists of three main components such as; a solar collector, a chimney and a turbine. The solar collector, which is a large semi-transparent surface absorbs the solar radiation and heats the ambient air that enters the system. The chimney generates the buoyancy-driven flow, which provides the rotation of the turbine located at the center of the chimney to generate electricity. By the advancement in computer technology, the use of CFD methodology for studying SCPP has become an extensive, robust and powerful technique. In this study, numerical simulations of the solar chimney through two-dimensional axisymmetric modeling by using CFD software is performed. Numerical results are verified with an experimental study from the literature. After ensuring good agreement with the experiments, the effect of different chimney configurations on SCPP performance is investigated. It is found that higher power output can be achieved with diverging chimney configurations compared to the conventional chimneys. Also, in the second part of the study, the effect of divergence angle on produced power is examined. It is observed that there is a critical divergence angle and after reaching this critical value, efficiency and power values decrease, so performance is reversely affected.
Utilizing Solar Chimney Power Plants (SCPPs) for manufacturing clean and environment-friendly energy has drawn a lot of attention in recent years and has (over the passing decades) become one of the most promising solutions in the solar energy field. Low efficiency, construction difficulties and other required improvements have encouraged researchers to work on this system. Many researchers put their efforts into proposing an optimized configuration for the main components, whereas others have proposed innovative ideas and add-on accessories to improve solar chimney power plants from an efficiency or construction viewpoint. This paper provides a comprehensive review of the past few decades and includes analyses of the theoretical, experimental and numerical studies conducted focused on optimizing the main characters of the system, such as the chimney, collector and Power Conversion Unit (PCU) together with other recently suggested innovative ideas and alternative technologies to improve solar chimney power plants efficiency. Concurrently, other researchers focused on hybrid solar chimney power plants to produce the desired by-product such as distilled water and so make SCPPs more practical.
Solar chimney power plant (SCPP) uses solar energy to hit the ambient air which when allowed to pass through a chimney runs a wind turbine that in turn runs a generator to produce electricity. The SCPPs are very huge structures with the ability to generate a significant amount of electricity to serve global power demand without any adverse effect on the environment. Interest in SCPP has become a popular and promising option to utilize solar energy due to pollution and climate change as well as the demand for electrical power globally. Dimensions of plant sub-components like collector area, chimney height, and its radius are the main parameters that needs be well synchronized to attain the best performance. In addition to the dimensional parameters, the design of the wind turbine is another important criterion to achieve the best performance. This is judged in terms of output power and the overall efficiency of the unit. Using detailed mathematical modeling, the plant power output and efficiency are projected for an extensive range of design and functioning parameters concerning the fluid flow and heat transfer characteristics. Different relative values between collectors and chimney with the best dimensions are mentioned to obtain cost-effective SCPP. Although remarkable advancement is noticed for designing and understanding SCPP, commercial SCPP has not yet been developed yet so far. This comprehensive review may help the researchers for a deep understanding of flow physics and to identify the key parameters and their value for the best designing of SCPP. Many hybrid models with further modification that merit commercial production of large-size SCPPs is also included in this study.
Flue gases exhausted from thermal power plants contain more than 50% of the fuel thermal energy. In the present work, experimental investigation was carried out to study the utilization of thermal energy in flue gases to enhance the performance of modified solar chimney consisting of Savonius wind rotor. A modified solar chimney model was designed and fabricated to carry out experimental measurement. The model consists of thermal energy conversion unit; Savonius wind rotor and a chimney. The thermal energy in the flue gas transfers to the air particles in the air channel across the absorber plate and results in upward air stream due to the buoyancy effect. With an absorber area of 2.36 m² and flue gas mass flow rate of 0.18 kg/s, air velocity of 4.1 m/s was achieved at the top of the thermal unit. Increasing the mass flow rate of the flue gas to 0.24 kg/s enhances the air velocity to be 4.6 m/s. The results have demonstrated the possibility of utilizing the thermal energy in the waste flue gas to enhance the performance of a solar chimney and facilitate the continuous operation during the absence of the sun.
In solar chimney power plants the air under the glass-covered collector is heated by solar radiation, and then released via a central chimney into great atmospheric heights. This mass-stream of warm air drives turbo-generators in the chimney foot producing electricity. The article describes recent progresses in research and development of this technology applicable primarily in arid zones.
This paper investigates the effects of ambient wind,
temperature lapse rates and nocturnal temperature
inversions on the performance of a large-scale solar
chimney power plant. The effect of prevailing
ambient winds at a reference site on plant
performance is evaluated, while different ambient
wind profile models are also considered. During the
daytime, the atmosphere surrounding the plant is
modelled using a dry adiabatic lapse rate (DALR)
and the International Standard Atmosphere (ISA),
while night-time temperature inversion effects are
also accounted for. Results indicate that windy
conditions impair plant performance considerably,
while nocturnal temperature inversions cause
significant reductions in night-time output.
Current energy production from coal and oil is damaging to the environment and non-renewable. Many developing countries cannot afford these energy sources, and nuclear power stations are an unacceptable risk in many locations. Inadequate energy supplies can lead to high energy costs as well as to poverty, which commonly results in population explosions. Sensible technology for the use of solar power must be simple and reliable, accessible to the technologically less developed countries that are sunny and often have limited raw materials resources, should not need cooling water or produce waste heat and should be based on environmentally sound production from renewable materials. The solar chimney meets these conditionsand makes it possible to take the crucial step towards a global solar energy economy. Large scale solar chimneys can be built now without any technical problems and at defined costs.
Cited By :3, Export Date: 4 January 2015
Rare techniques have been proposed for twenty four hour operation of a solar chimney power plant (SCPP). In this study, another technique is suggested by utilizing waste heat energy in the form of flue gases flow in conduits within the solar collector. The process of the heat and fluid flow within the collector were simulated using ANSYS software. The predicted performance and enhancement of the collector are presented and discussed. The results show a significant increase in the overall performance of the solar chimney power plant. At 1000 W/m2 solar radiation, the collector temperature rise is from 19 to 23 K, the updraft velocity is increased from 15.6 m/s to 17.1 m/s, the power output increased from 50.1 kW to 66.1 kW and the efficiency is improved from 0.116% to 0.144%. Although the technique contributes to the performance enhancement of the SCPP, it also contributes to the reduction of global warming by reduction of the exhausted flue gases temperature.
Floating Solar Chimney Power Stations (FSCPSs) is a new promising solar technology. The Floating Solar Chimneys are lighter than air constructions, that can be as high as 3÷4.5 Km giving to their respective power stations efficiencies from 4.5÷7%. The axial shrouded air turbines of the FSCPSs are geared to appropriate electric generators, In the present paper the Doubly Fed induction generatos (DFIGs), with small electronic control units (with power not more than 3.5 % of their generators rated power ), are examined as the best and most economical solution. Due to the FSCPSs characteristics, it can be proved that, at least 97% of the theoretically maximum production energy by the FSCPS can be supplied to the grid. The DFIGs can supply to the grid positive reactive power( on demand),and stabilize the grid when necessary. FSCPSs with Doubly Fed induction generators can be used for autonomous hydrogen production combined with appropriate electrolysis units.
A solar turbine power station (STPS) has three major components: A cyclical solar collector A solar chimney in the center of the solar collector A set of air turbo generators near the entrance of the solar chimney The power output of a STPS is roughly proportional to the height of the solar chimney and the surface area of its solar collector. In order to increase the power output and the efficiency of a STPS with a given solar collector, we must increase the height of its solar chimney. This can be achieved using floating solar chimneys. The floating solar chimney (FSC) invented by the author, is a lighter than air construction, made by successive balloon rings, that are filled with He or NH3. This permits to the FSCs to float in the air and thus to have heights up to several Km with any appropriate internal diameter. In the present paper an extensive presentation of the power output and the efficiency of the STPSs with FSCs is given. As it is shown the power output and the efficiency of the STPS depend on the dimensions of the FSC and the solar collector on the loss coefficients of its FSC and on the environmental characteristics (solar irradiance, temperature and pressure). The efficiency of a STPS with a rated power output of 100 MW is between the ranges of 4.5% to 7% if its FSC heights are in the range of 3000 m to 4500 m.
The heat losses within exhaust gases are an unavoidable part of operating any
fuel-fired system. The flue gases still hold considerable thermal energy, which is
exhausted to the atmosphere as waste heat and contributes to global warming.
This paper presents a developed technique to enhance the performance of low
temperature solar thermal systems by utilization of thermal energy recovery of
flue gases. A CFD model was established based on the energy, momentum and
mass conservation and the state equation in 2-D, steady assumption with kepsilon
for the turbulence modelling using FLUENT – version 6.2.16 software.
The model simulates the thermal and fluids flow processes in an inclined
modified solar chimney. The flue inlet temperature was varied as, Tf g= 603K,
843K, and 983K. The simulation results were validated by comparison with
experimental results obtained from a lab scale model, and acceptable agreement
was gained. When the flue temperature is increased from 605K to 843K, the
performance is enhanced by 75%. The interesting find is that the efficiency of
heat collection tends to increase as the absorber length increases up to a certain
length, and then starts to decrease. In this study, the suitable dimension for solarflue
gas collector is about 2.5 m.
Keywords: solar chimney, numerical analysis, CFD, energy conversion,
energy recovery, flue gases.
1 Introduction
The potential of solar chimney as an energy source to produce power has been
widely researched and successfully demonstrated by numerous previous
experimental studies. A solar chimney power plant is one of the proven
In this study, the performance optimization of a small-scale prototype solar chimney power plant (SCPP) under specified meteorological conditions is considered in Kerman, Iran. This power plant has been built based on the initial evaluations due to the high solar irradiation in this area and also the simple technology of SCPP. This solar chimney has a height and diameter of 60m and 3m, respectively, and the radius of its single-glazed solar collector is 20m, that is able to produce close to 400 Watts electric power in the maximum solar irradiation. To analyze the performance of the SCPP, a comprehensive SCPP analysis including analytical and numerical models is developed. This mathematical model is validated by comparing with the practical power output of the Manzanares prototype plant. Also the mathematical model is verified with the practical power output of the Kerman prototype plant and is used to predict the performance and operating range of this plant. For this purpose, at first the effect of the main dimensions of the plant on power output is investigated. Then to optimize the performance, the appropriate dimensions of SCPP are determined based on an approximate cost model.
So as to promote the power plant performance, some developments and progressive configurations were suggested for the components of the solar updraft tower power plants. A detailed literature survey of development of performance enhancement techniques were presented and discussed in the present paper. The survey gives a summarize overview of the developments in each of the components key area inspect to raise the performance of the currently solar power plants.
The concept of using flue gas waste heat as a backup in a solar chimney power plant is driven by the objective of solar chimney plant performance enhancement. This paper presents experimental results of thermal field of hybrid solar-flue-gas chimney power plant at different mode (solar mode, hybrid mode and flue gas mode). The experimental test rig consisted of two inclined absorber plate and diffuser surface with total area of 3.15 m2, flue gas channel (1m × 3m × 0.05m), greenhouse (air flow channel of 1m × 3m × 0.16m at inlet and 1m × 3m × 0.075m at exit), chimney of diameter 0.15m and height of 4m, flue gas inlet diffuser (1m × 0.3m × 0.05m) and flue-gas source (biomass burner coupled with centrifugal blower powered using a variable speed motor). The temperature distribution in the hybrid solar-flue gas chimney power plant test-rig was measured. Temperature difference between the chimney base (absorber plate exit air) and the ambient were studied which is the driving force in solar chimney power plant. On solar mode, the driving force (temperature difference between the absorber plate exit air and the ambient air) gave a maximum ΔT of 27.6 °C at irradiance of 797 W/m2. With flue gas as thermal backup during the day, maximum ΔT reached 38.1°C for inlet flue-gas temperature of 101.6 °C and irradiance of 672 W/m2, with flue gas as the only source of thermal energy (night mode), the temperature difference, ΔT, got up to 25.9 °C at a flue-gas inlet temperature of 107.6 °C. The solar mode experiment carried out after night mode experiment shows that the ΔT of the system the next day was enhanced as the temperature difference increased from sunrise contrary to the low temperature raise experienced on normal solar day.
The goal of this study is to analyze particularly the sensible heat storage physical process in a Solar Updraft Tower collector taking into account the transient heat transfer in ground through conduction, convection and solar radiation and the use of water bags. Simulations were carried out varying the thickness of some water bags sets with and without insulation regarding thermal stratification effect. Results disclosed that thicker water bags can reduce more efficiently the daily temperature spam and thermal stratification is an import thermal effect. Water bags alone are however not enough to break efficiently heat peaks.
The structure of Solar Updraft Towers is basically a circular cylinder, which may turn into a hyperboloid at lower levels in order apply benefits of shape strengthening. The height of the tower is up to 1.5 km and it is usually designed as a thin reinforced concrete shell. The wind action is the main natural hazard, which plays a decisive role for the feasibility of the technology. An extensive wind tunnel investigation has been recently performed at WiSt laboratory at Ruhr-University Bochum (Germany) and at Criaciv laboratory at University of Florence (Italy). The tests highlighted in no-efflux conditions (out-of-use of the power plant) a new phenomenon regarding cross-wind loads, induced by a bi-stable and asymmetric flow distribution. It is created by compartments between stiffening rings along the tower and enhanced by a strong interaction with free-end flow structures at the top of a finite length circular cylinder. A proper positioning of the rings should allow to avoid this phenomenon.
Solar updraft chimneys (SUCs) form as engines of solar updraft power plants tower-like shell structures of extreme height with rather thin shell walls, similar to high chimneys comprising multiple flue gas ducts. The height of presently pre-designed SUCs reaches up to 1000 m. Thus they are exposed chiefly to extreme natural wind-loads, and to thermal actions from the internal flow of warm air. As first design step, the structural analysis of solar chimneys generally is carried out by linear elastic models. For optimization, the typical shell-like wind stresses have to be constraint towards a more beam-like response behavior, approaching a linear stress distribution over the chimney diameter. This requires rather strong ring stiffeners, either as spoke-wheels in the designs of SBP (Schlaich Bergermann and Partners) or as external stiffeners in the designs of K&P (Kratzig and Partners). Both alternatives require considerable construction efforts for the rings leading to high costs. There exists an interesting alternative to this stiffening, namely applying only medium soft external rings to the SUC shell, and admitting large-widths cracking in the limit state of failure. This cracking equalizes the meridional strains over the chimney's cross-section, saving large amounts of reinforcement steel in the SUC, but requiring materially nonlinear analyses under crack-formations. The manuscript will sketch pros and cons of the classical ring-stiffening, derive this new nonlinear concept and demonstrate the crack analysis by example of a 750 m high solar chimney. [GRAPHICS] .
Solar chimney power plant (SCPP) with a long life span is a promising large-scale solar thermal utilization technology. This paper performs an economic analysis for the conventional solar chimney power plant (CSCPP) and the sloped solar chimney power plant (SSCPP) in Northwest China. Cash flows are influenced by many factors including the investment, the payback period, the inflation rate, and the sale price of solar electricity. The techno-economic analyses of the CSCPPs and SSCPPs are performed taking Lanzhou, China as a case study. The results show that the SCPP investment is influenced by both its configuration and the material price, and the SSCPP is more cost-effective than the CSCPP during the system life span. In addition, the SCPP with large power capacity holds good competitiveness with the conventional fossil fuel combustion plants. The economic evaluation of building SCPPs in Northwest China is of high significance considering the local abundant solar radiation, favorable government policy, and under-developing economics.
A feasible and also promising system for the utilization of solar energy is an upwind power plant. For some years, such a power plant has been in operation as an experimental plant at Manzanares (Spain) and in the meantime has provided sufficient data which allow well-founded estimates for greater and improved plants. The authors explain the mode of operation of the wind power plant, present the most important components and interpret the results from measurements and operational experience. A glance at the technical development potential of this solar energy utilization as well as at questions of cost effectiveness conclude the paper.
Aiming at the economical and technical problems in the desalination and the power generation of solar chimney, the integrated system has been put forward, from which fresh water and electricity can be obtained. Firstly, the performance of the integrated system has been initially estimated based on the climate conditions in Hangu area. Secondly, a small optimized experimental system has been set up, from which the data of the direct and indirect condensation were measured. By comparing the experimental results with theoretical estimation, the economic and theoretical feasibilities of the system were analyzed. The theory and the experiment results showed that the integrated system was doable if suitable heat exchanging way was chosen, at the technologies of the solar chimney and seawater desalination will be promoted at the same time.
The solar chimney is a natural draft device which uses solar radiation to provide upward momentum to a mass of air, thereby converting the thermal energy to kinetic energy. A set of equations is developed to describe the fluid dynamics of such a chimney. Effects of various configuration parameters, such as the envelope shape, height and entrance to exit area ratio, on the available power and chimney efficiency are considered. Among these, the last factor is found to have the most influence on the chimney performance. Directions are indicated for future work for making the solar chimney a viable proposition.
The integrated solar chimney system for power and freshwater from seawater has been put forward. 1.0 kWh wind electric power and 0.74 t freshwater per collector square meters per year could be obtained by the integrated system. The vapor condensation velocity model of indirect condensation of air-vapor was discussed to associate the air concentration and temperature with condensation process. In the small experimental system the wind velocity, output of freshwater and temperature were measured for the design of condensation system.
This article is available through this link:
https://www.saimeche.org.za/resource/collection/F86B1F29-85C6-45A5-ACBC-0B6827AD6C1F/Kr_ger_and_Blaine-1999_03__600_dpi_-_1999__15_3___85-94.pdf
In the current study, the performance analysis of a solar chimney power plant expected to provide off-grid electric power demand for villages located in Iranian central regions is presented. High annual average of solar radiation and available desert lands in the central parts of Iran are factors to encourage the full development of a solar chimney power plant for the thermal and electrical production of energy for various uses. The interested is in Kerman where solar radiation is much better than other areas of Iran. The obtained results clear that solar chimney power plants having 244 m diameter can produce from 25.3 to 43.2 MW h of electricity power on a site like Kerman during different months of a year, according to an estimation calculated from the monthly average of sunning. This power production is sufficient for the needs of the isolated areas and can even used to feed the main electrical grid. [DOI: 10.1115/1.4006966]
Cited By :12, Export Date: 4 January 2015
An experimental investigation of a solar chimney turbine design is undertaken. The aim of the program is to demonstrate and evaluate a proposed solar chimney turbine design. The measured results of an experimental model turbine are presented and the turbine efficiency calculated. The current turbine design has a total-to-total efficiency of 85–90% and total-to-static efficiency of 77–80% over the design range. Secondary objectives are to compare the measured and predicted results and through investigation of the experimental results suggest improvements to the turbine design.
The solar chimney is a simple renewable energy source consisting of three main components, a solar collector, chimney and turbine. Air under the collector is heated by the greenhouse effect. This less dense air rises up a chimney at the collector centre and drives an electricity-generating turbine. The operation of a solar chimney power plant is simple but high component efficiencies are needed for successful operation. A turbine design based on the design requirements for a full-scale solar chimney power plant is presented. The design integrates the turbine with the chimney. It is proposed that the chimney base legs be offset radially to act as inlet guide vanes and introduce pre-whirl before the rotor to reduce the exit kinetic energy. A three-step turbine design method is presented. A free vortex analysis method is used to determine the major turbine dimensions. A matrix throughflow method predicts the flow path through the inlet guide vanes and rotor. Finally the blade profiles are design using an optimization scheme coupled to a surface vortex method to achieve blades of minimum chord and low drag. The proposed turbine design can extract over 80% of the power available in the flow.
The objective of this paper was to present a comprehensive analysis including analytical and numerical models which were developed to predict the performance of a solar chimney power plant in Kerman, Iran. The numerical model results including air temperature, velocity and electrical power output were validated by comparing with experimental data of the Manzanares prototype power plant. Also the mathematical model was verified with the practical power output of the Kerman pilot plant. Also in this paper, a novel approach to evaluate the influence of the site altitude on the potential of solar chimney power plants was presented and thereby a coefficient called altitude effectiveness was defined using Manzanares prototype geometrical parameters in different site altitudes. The developed model was applied to improve the performance of a solar chimney pilot power plant built in Kerman, Iran. Based on an approximate cost model, the thermo-economic optimal configurations of the pilot power plant were illustrated; and also it was found that the chimney diameter was the most important structural dimension to improve the performance of this pilot power plant.
An unsteady-state mathematical model of the heat transfer and flow of the integrated system under no-load condition has been developed. The influence of heat collector structural parameters on the system has been researched. The results show that the negative pressure, draft force, velocity and airflow temperature rise of integrated system increase significantly with the increasing of collector diameter. The collector diameter has no influence to the seawater temperature, glass cover temperature and hourly freshwater yield per unit area basically. With the increasing of collector inlet height, the negative pressure, velocity and temperature rise decrease, the seawater temperature and the glass cover temperature also decrease. The amplitude value of the glass cover temperature drop is bigger than that of the water temperature drop. The hourly freshwater yield increases in certain time periods and decreases in other time periods. The influence of collector inlet height on the characteristics of integrated system has a tendency to weaken with the increasing of collector inlet height.
An unsteady-state mathematical model of the heat transfer and flow of the integrated system under no-load condition has been developed. The field distribution characteristics of the pressure, velocity and temperature of the integrated system have been researched. An optimization method based the temperature field distribution at the region where the wind turbine is placed has been proposed. The results show that the relative pressure within the system is negative value everywhere. The relative pressure and temperature are larger, the flowing is slowed down and the temperature distribution is non-uniform at the bottom of the center of the heat collector. The maximum negative pressure appears at the junction between the outlet of collector and the inlet of chimney, thus the place is the ideal region which the wind turbine will be installed. Optimizing the geometric dimensions of the local flow passage, the negative pressure and draft force can be significantly improved, and the speed can also be improved, and the energy loss can be obviously reduced. The flowing characteristics of the airflow in the collector changes little after the optimization of the geometric dimensions, the optimization does not basically affect on the freshwater production in the still.
Comparison experimental devices with the different chimney structural parameters for the solar chimney power generation system integrated with seawater desalination have been set up. The performances of these integrated devices have been tested and researched comparatively under the actual weather condition. Results show the seawater regeneration body in the system has certain load range to the flow rate of airflow. It is beneficial to strengthen the seawater evaporation, enhance the freshwater output that the diameter of the chimney is enlarged and the height is enhanced in this range. To the electricity power generation of the system, whether to increase the chimney diameter, or increase the chimney height, the volume of the chimney will be increased when other parameters are fixed, namely the flow rate of airflow will be increased, and the power generation will be significantly increased, thus the solar energy utilization efficiency will significantly improve. In the actual project, it is very important that the optimal combination of different height and diameter of the chimney can be selected according to the actual situation for development of large-scale integrated system.
A comprehensive basic analysis for various counter-rotating turbines is given with the blade element stage assumption. Similar to the classical analysis of common turbine stages, the appropriate independent variables and evaluation criteria of the counter-rotating turbine stages are first presented and then three typical kinds of rotating blade rows are defined and all possible typical schemes of counter-rotating turbine stages are enumerated. Their performances of specific work, load factor distribution between two counter-rotating shafts and efficiency are analysed and discussed for different shaft rotating speed ratios. This information is useful for the selection and preliminary design of a counter-rotating turbine. From the analysis results, it is concluded that the load capacity per unit engine length of counter-rotating turbines can be much higher than that of common turbines (approximately) twice) without efficiency penalty or even with higher efficiency. Some triple counter-rotating turbines suitable for three shaft gas turbine power plants are proposed and analysed briefly too.
The compressible transient model of solar chimney power plant system was proposed. It was added to the pressure equation and the ideal gas state equation basis on the heat balance equation for the solar collector model. The air flow station can be easily calculated with the improved model. The results of dynamic changes of the total pressure difference calculated in the model were in good agreement with the given actual measured values in references. The solar chimney model was considered the influence of fluid pressure on the density. The influence of the structural chimney on the chimney efficiency was analyzed with the established model. It was shown that the chimney efficiency changes significantly with the chimney height and its diameter. The chimney efficiency was decreased with a convergent chimney shape while increased with the divergent one. When the tilt angle of chimney reached a peak and then further increased, the chimney efficiency was the constant. These results will provide the important reference to improving the system efficiency.
Until today, the biggest solar updraft tower power plant ever built and tested was the 50 kW Spain plant in Manzanares. Since then no real plant has been built, whilst many grand plans have been drawn and given up. Solar Wind Power (SWP) is an energy form in search of its destiny: it is time to find a real market for SWP. This market is currently forming and we call it 'evening power'. SWP transforms sunlight into heat, heat into hot artificial wind, and this wind into electricity. The three steps of transformation allow SWP to delay the generation of electricity from the daily peak of solar radiation into the evening. In the evening, the greater power demand cannot be met with other renewable CO2-free energies like wind and photovoltaic. SWP has been tested once, thirty years ago - it is time for a second trial: the Intermediate Solar Wind Power Plant (ISWiPP). The goal is to develop, test and measure SWP's potential for heat-storage and evening power output. The technology for constructing a light steel-tower with a concrete base will be tested under real-life conditions and technologies for heat storage will be developed. The ISWiPP will enable investors to prepare for large SWiPP with hybrid (concrete and steel) towers of 1000 m height or more. This development growth path is realistic and adequate to overcome the current impasse. Like all CO2-free energy forms SWP depends very much on the location chosen. Locations with strong winds, or sand- and dust-storms, are inadequate for SWP. A good location for a SWiPP is a hot, flat and rocky desert, not too far from a city with a demand for evening power.