Energy, exergy, economic and environmental (4E) analyses of a conceptual solar aided coal fired 500 MWe thermal power plant with thermal energy storage option

Abstract

In this paper, a conceptual cycle has been developed by integrating a solar field consisting of parabolic trough collectors with an operating 500MWe coal fired thermal power plant for preheating the condensate/feed water. The effect of solar aided feed water heating (SAFWH) has been studied separately for each feed water heater (except LP Heater-1 and deaerator) by placing a feed water heat exchanger (FWHE) parallel to the heater under study. Energy, exergy, economic and environmental (4E) analyses have performed on this conceptual cycle in fuel saving mode by complete substitution of bleed steam with solar energy. Performance parameters (Energy and exergy efficiency, net unit heat rate, fuel savings and solar contribution) and economic parameters (Levelised cost of electricity generation (LCoE), simple payback period) and environmental parameters (annual reductions in coal consumption, CO2 and ash generation) have been calculated. The results have shown that levelised cost (cents/kWh) and simple payback period (years) for solar aided feed water heating in HPH-7 without and with thermal storage are 5.045/5.196 and 5.13/6.21 respectively. Sensitivity analysis has been carried out to find out the sensitivity of LCoE with respect to discount rate, plant capacity factor and fuel cost.