Hybrid photovoltaic/solar chimney power plant combined with agriculture: The transformation of a decommissioned coal-fired power plant

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.