4-E (Energy-Exergy-Environment-Economic) Analysis of Stand-Alone Solar Thermal Power Plants and Solar-Coal Hybrid Power Plants

Abstract

This article deals with 4-E (energy-exergy- environment-economic) analysis of stand-alone solar thermal power plants (SASTPs) to establish their techno economic feasibility in comparison with coal-fired (CFPs) and solar-coal hybrid power (SCHPs) plants. The analysis is carried out out for various plant capacities ranging 1- 50 MWe considering a 50 MWe coal-fired power cycle as reference. The plant energy efficiency of SASTPs without thermal energy storage is compared to CFPs. The inclusion of thermal storage in SASTPs reduces plant energy and exergy efficiencies. The CO2 emission and ash production for a 50 MWe SCHP are less by 0.3 kg/kWh and 8400 tons/year, respectively, as compared to CFP. The levelized cost of electricity (LCoE) of a reference plant is Rs. 2.75/kWh whereas the LoE is higher by Rs. 10.59- 11.30/kWh and Rs. 2.10/kWh, respectively, for SASTPs and SCHPs. The plant energy and exergy efficiencies decrease by 3 to 4 percentage points for 1 MW power plants.