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With energy resources being fossil fuel-based, increasing energy production has already reached levels that threaten human health. In this situation, the use of alternative energy sources is seen as the only solution. Solar energy is seen as the most promising source among these alternative energies in terms of its potential. Hence, therefore, this study focuses entirely on one of the solar energy sources. This research aims to assess the impact of the design and underground additional heat source (AHS) on the system performance based on the Manzanares pilot plant (MPP), the first on-site practice of solar chimney power plants. Divergent chimney-SCPP with sloping collector (DISCPP) is analysed in the present work. For DISCPP, the influence of the underground AHS in the range of 50–250 °C on the system outputs is examined. The study demonstrates a remarkable enhancement in power output (PO), with the plant generating 51,545 kW under the reference case conditions. The findings signify that when utilising the DISCPP system, the output soars to 247,672 kW under identical climatic conditions. During sunless hours, a PO of 61,956 kW is achieved with the DISCPP at an underground AHS temperature of 50 °C. Moreover, when the source temperature reaches 250 °C during sunless hours, the DISCPP system continues to deliver a significant output of 450 kW. These outcomes underscore the exceptional performance and reliability of the DISCPP system, even under varying conditions.

The article deals with the effects of change in dimensions of solar chimney upon the thermodynamic characteristics of the air flowing inside it. The solar chimney at Manzanares (Spain) has been selected as the base model for this study. ANSYS-Discovery-Aim 2019 R1 has been used for the simulation of different geometric variations of solar chimney along with its validation with the work by Haaf et al. It is found that of all the geometric changes, the increase in roof height is undesirable. While for others like increase in chimney height, increase in chimney diameter and increase in collector radius gives desirable results in terms of increase in velocity of air. Also, for the case with an increase in chimney diameters; it is found to be suitable if the turbines are placed at the outlet of the collector and not within the chimney.

Solar chimneys are renewable energy systems designed to enhance natural ventilation, improving thermal comfort in buildings. As passive systems, solar chimneys contribute to energy efficiency in a sustainable and environmentally friendly way. The effectiveness of a solar chimney depends on its design and orientation relative to the cardinal directions, both of which are critical for optimal performance. This article presents a supervised learning approach using artificial neural networks to forecast the performance indicators of solar chimneys. The dataset includes information from 2784 solar chimney configurations, which encompasses various factors such as chimney height, channel thickness, glass thickness, paint, wall material, measurement date, and orientation. The case study examines the four cardinal orientations and weather data from Mexico City, covering the period from 01 January to 31 December 2024. The main results indicate that the proposed artificial neural network models achieved higher coefficient of determination values (0.905-0.990) than the baseline method across performance indicators of the solar chimney system, demonstrating greater accuracy and improved generalization. The proposed approach highlights the potential of using artificial neural networks as a decision-making tool in the design stage of solar chimneys in sustainable architecture.

Energy supply and ventilation for isolated offices in rural areas are strongly recommended to be powered by renewable or standalone energy systems under the concept of net-zero-energy building (netZEB). A rooftop solar chimney is one of the adopted methods for space ventilation to improve thermal comfort. This approach has not been investigated under forced convection to support the netZEB. The objective of the current work is to experimentally assess the effectiveness of natural and forced ventilation methods for a prototype net-zero-energy office with a rooftop solar chimney. The prototype is a low-cost office constructed in the solar research site at University Teknologi PETRONAS, Malaysia. The weather is typical of a tropical climate. Three cases have been investigated. Case-1 with closed-door natural ventilation, Case-2 with open-door natural ventilation, and Case-3 with forced ventilation. Many ventilation parameters have been evaluated to compare the three ventilation cases. The measurement results show that, whether natural or forced, the installed chimney created a stack effect that reduced the temperature inside the office, but not to the required comfortable ventilation temperature. The mean measured indoor temperatures are higher than the proposed ventilation comfort temperatures, with differences of 6, 5.2, and 3.35°C for Case-1, Case-2, and Case-3, respectively. In natural ventilation, Case-2 reduced the indoor-to-outdoor temperature ratio by 2.7% and improved thermal comfort by 32.4% compared to Case-1. With forced ventilation, Case-3 reduced the indoor-to-outdoor temperature ratio by 27.3% and improved thermal comfort by 65.2% compared to Case-1. The large, unshaded glass windows have a significant negative effect on ventilation, and it is recommended to avoid such a design for netZEB in the tropical climate.

The present work involves a new and novel upgrading design to the classical solar chimney power plant (SCPP) structure. The SCPP design was modified by adding a co-centric secondary external chimney to the SCPP structure to enhance energy production. In the new improved design, named the solar double-chimney power plant (SDCPP), the internal chimney, operates like a traditional SCPP to produce electricity during the daytime whereas the secondary external chimney operates as 10 cooling towers (CT) in a series. Each CT is equipped with a turbine and water sprinklers for further energy production. The new design offers the operation of the SCPP during the day and the continuous operation of the CT (day-and-night). A mathematical model that includes the energy and mass balance equations of the system was built using MATLAB. The SDCPP system produced up to 993 MWh of electrical energy, which is 2.6 times higher than the traditional SCPP (377 MWh). The new design configuration achieved a percentage of thermal efficiency (%ηth) of 1.6%, which is 200 times greater than the SCPP. The economic assessment of the new system revealed a 50% reduction in the localized cost of energy (LCOE) compared with traditional SCPP. The key advantage of the new design is related to the use of low-cost material in constructing the secondary chimney to reduce the fixed capital cost and prompt the economic feasibility of the system. Overall, the proposed SDCPP offers a feasible and economic solution to produce electricity and to potentially reduce greenhouse gas emissions.

Floating Solar Chimney Power Plant (FSC) proposed by Papageorgiou is regarded as a novel type of Solar Aero-Electric Power Plants with fundamental characteristics of low cost and unaffected seismic chimney. The main disadvantage of the proposed system is the tilting of the floating chimney in windy conditions compared with a conventional reinforced concrete one. In the present research, the ambient crosswind (ACW) effect is studied on an FSC with experimental and numerical approaches. An experimental floating chimney integrated with an appropriate solar collector was designed, built, and tested under real-world conditions, and the experimental results were used for validations of the numerical analysis. Three-dimensional numerical analysis was performed to study the performance of the tilted floating solar chimney exposed to the ACW and then compared with a conventional type. Numerical results show that a tilting FSC with lower apparent height can operate more efficiently than a vertical concrete chimney in windy conditions due to eliminating adverse effects of tip vortices on updraft flow in the system. The results also show that an optimum tilting angle (OTA) exists for the specified plant and critical or prevailing wind speed, making ACW adverse effects minimum. Floating solar chimney design can be enhanced significantly based on achieving optimum tilting angle in windy conditions.

The depletion of fossil fuels and climate change are major worldwide problems. Unlike hydrocarbon resources, solar energy is a clean, inexhaustible, and sustainable power source to meet all of humankind’s energy demands. Solar chimney power plants (SCPPs) having a simple design are capable of generating large‐scale solar powered electricity. The systems have three primary components: a chimney, turbine, and collector. The optimization of the chimney geometry plays a key role in achieving the peak efficiency of SCPPs. In the current work, a three‐dimensional (3D) model on the basis of the Manzanares prototype with a chimney height ( H ) of 194.6 m and radius ( R ) of 5.08 m is developed to identify optimal height for the innovative constricted chimney section configurations via ANSYS FLUENT. The height of the narrowed chimney sections varies as 1/4, 1/8, 1/16, and 1/32 of H for a fixed radius as 1/3 of R . The findings indicate that the power output ( P o ) increases with decreasing the narrowed section height from H /4 to H /32 owing to enhanced mass flow rate and turbine pressure drop. The highest P o of 65.9 kW is gained with the configuration with the height of H /32 and P o enhances by 43.3% compared to the base case at 1000 W/m 2 . The novel equations are improved from the numerical data to estimate the performance features. Besides, the impact of the narrowed section radius on the performance is examined to optimize the dimensions of the constricted section. It is found that a decrease in the narrowed section radius from R /3 to R /5 for a constant height of H /32 leads to a reduction in P o by 1.2% because of a remarkable decrease in mass flow rate. H /32 and R /3 can be optimum height and radius value for the reduced chimney section to augment system efficiency.

Solar chimney power plant (SCPP) is an interesting project to produce clean and sustainable energy. An efficient SCPP system requires a very high chimney, and thus the optimization of the chimney shape presents an important way to enhance the SCPP performance. The aim of this paper is to analyze the effect of the divergent chimney shape on the airflow behavior inside SCPP. A comparison between four chimney shapes is carried out using CFD method: two cylindrical chimneys with different diameters and two divergent chimneys with different shapes. Indeed, both parameters were studied: the ratio of the inlet and outlet diameter of the chimney and the shape of the chimney which both hyperboloid and conical. The SCPP prototype was tested numerically and experimentally to validate the present computational outcomes. The obtained results confirm that the divergence shape affects directly the efficiency of the SCPP system. Moreover, the hyperboloid chimney presents the efficient solution which produces an important power output with keeping the chimney height constant.

Several geometric parameters have been investigated in solar chimney power with the aim of determining the optimal geometric parameters and enhancing power generation. The aim of this study is to determine the optimal dimensions of the sloped absorber surface and analyze its impact on the power output of the system at the Manzanares plant. The sloped absorber surface studied includes a singular triangular shape where the effect of the central high and absorber slope radius is studied. To conduct this study, A Computational Fluid Dynamics CFD model developed using COMSOL Multiphysics with the k – ε turbulence model was employed. The outcomes of this study demonstrate that the maximum air velocity in the reference Manzanares design, initially measured at 15 m s −1 , increases by 26% with the optimized sloped absorber configuration. Specifically, at a central height of 1.10 m and an absorber slope radius of 122 m, the maximum velocity reaches 18.9 m s −1 . Furthermore, the power output rises by 34%, reaching 67 kW compared to the reference case of 50 kW.

Abstract Solar chimney technology is a new generative technology that generates electricity from the direct incident solar radiation from the sun. It is a low-temperature operating solar thermal system that generates power on the basis of three technologies (chimney/draft technology, wind turbine technology, and greenhouse effect technology). It consists of three fundamental parts: turbine, vertical chimney of decent height and a collector made up of glass panes to absorb the radiations from the sun. Effective use of this technique can generate electricity in abundance and can operate twenty-four hours nonstop annually and can solve the electricity shortage issue in a country like India where the sunlight radiations are immense in intensity and stretch to the major parts of the country. Since its inception, solar chimney technology has seen prosperous advancement but has not witnessed full-scale utilization because of various techno-economic and environmental aspects. This study discusses the critical review of the solar updraft/chimney technology in various parts of the world and emphasizes its important aspects.