Cost and environmental benefits of coal-concentrated solar power (CSP) hybridization in India

The footprint of concentrated solar power (CSP) technology in the Indian energy mix is limited since the country mostly receives moderate direct normal irradiance (DNI) (3.5e4.5 kWh/m2/day) and the current capital costs are high. With simulations using an improved DNI database, we compare the costeffectiveness of clean energy dispatch from stand-alone CSP with thermal energy storage (TES) and coal-CSP hybrid systems. The capital costs must be significantly reduced for the economic feasibility of stand-alone CSP-TES plants in India. The levelized cost of electricity (LCOE) and environmental advantages of coal-CSP hybrid systems are presented by simulating the hybrid system in two modes at three locations in India with contrasting DNI profiles. A fraction of turbine bleed-steam is partly/fully replaced by solar-assisted feedwater heating (SAFWH) in the booster mode, while the yield from burning coal is partly replaced by solar heat in the fuel saver mode. Results show that the cost of additional  energy generated due to SAFWH in booster mode is up to 51.4% less as compared to a stand-alone CSP, even when operating at sites with moderate DNI. In the fuel saver mode, up to 40 thousand tons of coal can be annually saved with SAFWH, thus reducing CO2 emissions by 1.7% as compared to a stand-alone coalfired plant