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.

Geometric parameters in solar chimney power plants are numerically optimised for the purpose of better power output figures. Several parameters have been investigated in the pilot plant such as chimney height and diameter, collector diameter and slope, and slenderness. However, ground slope has not been studied to date despite its perspicuous impact on turbulent flow. In this study, the impacts of the different slope angles of the ground, where the solar radiation is absorbed through the collector, on the main performance parameters of the system are numerically analysed through a reliable CFD software ANSYS FLUENT. By considering the actual geometric figures of the pilot plant, a 3D model is constructed through DO (discrete ordinates) solar ray tracing algorithm and RNG k-ε turbulence model. For the solar intensity of 1000W/m², the maximum velocity inside the system is found to be 14.2m/s, which is in good accordance with the experimental data of 15.0m/s. Starting from 5m inside the collector, the chimney inlet heights are reconfigured 0.209, 0.419, 0.625, 0.838, and 1.04m, respectively, and when the ground slope is 0.1, 0.2, 0.3, 0.4, and 0.5, the changes in the performance output of the system are investigated. For the reference case which refers to the horizontal ground, the maximum air velocity is determined to be 14.2m/s and the power output is 54.3kW. However, when the ground slope is made 0.5, it is observed that the maximum velocity increases by 37 to 19.51m/s, and the power output is enhanced to 63.95kW with a rise of 17.7. Sloping ground is found a key solution to improve the turbulent effects inside the plant, thus to enhance the electrical power output.

This research examines the effect of using Bayburt stone or basalt as an energy storage unit in SCPPs. The effect of using low-cost materials on the system performance is evaluated. Based on the Manzanares pilot plant (MPP), a 3D CFD model was created. Geometric parameters were kept constant in simulations performed with ANSYS FLUENT engineering commercial software. In addition to DO (discrete coordinates) for the radiation model, the solar ray-tracing algorithm (SRTA) and the RNG k-e turbulence model (RNGTM) were solved, coupled, and the outputs of the system were evaluated at outdoor temperatures of 290 and 300 K. The temperature and velocity distributions, as well as power outputs (PO) of the system by using Bayburt stone and basalt as ground material, are compared for different outdoor temperatures and solar radiation conditions. It is understood that the use of both materials contributes to the performance of the system at a similar rate and can be used economically. It is noticed that the plant gives a PO of approximately 41,636 kW with both storage materials at a radiation intensity of 800 W/m² and an outdoor temperature of 300 K. It is seen that the outdoor temperature affects the temperature rise in the plant, which is higher at 290 K.

In this study, based on the Manzanares prototype, a typical SCPP system is considered with a collector height of 1.85 m, a chimney with a height of 194.6 m and a diameter of 10.16 m, and a collector with a radius of 122 m. With the 3D CFD model designed in ANSYS, the impacts of the change in the collector radius and collector height on the system performance are analysed by considering the turbulence effects. The numerical results are compared with the experimental data on the power output capacity of the pilot plant at different radiant fluxes and a good agreement is obtained. Then, by taking the chimney height and diameter constant, the numerical solutions are repeated for different collector radii in the range of 52.5-175 m. The results indicate that increasing the collector area, which means increasing the energy entering the system, leads to a notable improvement in the power output of the pilot plant. With a collector radius of 175 m, a power output of 95 kW can be obtained whereas it is 55 kW in the reference case with a collector radius of 122 m. Similarly, the solutions are repeated by changing the collector height between 1.1 and 4 m while keeping the other dimensions constant. It is seen that the increase in collector height negatively affects the performance of the system. It is observed that reducing the collector height to 1.1 m for the pilot plant can increase the power output to 61.77 kW.

Solar chimneys are popular systems for their simple structures and clean energy generation. Thanks to its semi-permeable structure, the collector, one of the system’s basic elements, transfers solar radiation to the system. As a result of the heating of the system air under the collector by the solar radiation passing through the collector, it is directed to the high chimney in the collector centre. During the upward movement of the system air, it converts its energy into electricity via a turbine. Due to its large structure, estimating the amount of energy entering the collector system creates a great cost. The ideal size for the collector is therefore important. This study offers a recommendation for the ideal collector size for the pilot plant in Manzanares in terms of collector size and power output. While 59 kW power output is obtained with the system with a collector radius of 122 m in the reference case, it is observed that the power output increases by 78% when the collector radius is increased to 170 m and the collector area is doubled. The ratio of the ideal collector radius to the reference size for the pilot plant should be in the range of 1–1.5.