Techno-environmental and economic analysis of a coal-based power plant integrated with solar field

Abstract

Limited availability of conventional energy sources and the problems of environmental degradation associated with them compels the need for a supply of new sustainable energy options. Among renewable energy sources, solar thermal energy is the most abundantly available and feasible option for electricity generation. Solar-thermal-only plants have a very high initial investment and, due to the sporadic nature of solar energy, can be operated only during the daytime. This limitation of only solar-thermal plants leads to an innovative idea of combining solar energy with coal-based power plants. This study investigates the hybridization of an existing 660 MW power plant with concentrated solar thermal energy on technical, environmental, and economic criteria under three different replacement options. The results obtained using MATLAB Simulink (R2017a) showed that the cycle efficiency increases from base case cycle efficiency, that is, 41.74% to 44.36%, 47.41%, and 48.72%, respectively, for all three replacement options. The economic analysis showed that the levelized electricity cost (cents/kWh) for all three replacement options is 4.56, 4.69, and 4.82, respectively. The payback period (years) is found as 3.3, 3.7, and 3.9, respectively. The environmental factors such as annual reductions in coal usage and CO2 emissions, and solar contribution are also calculated. The outcomes of this research will help to reduce global warming and climate mitigation.