Making solar electricity dispatchable: A technical and economic assessment of the main conversion and storage technologies

The techno-economic performances of five different solar-electricity conversion technologies (photovoltaic, solar tower, parabolic trough as well as two hybrid PV/CSP systems) associated with three energy storage means (electrochemical, thermal, and thermophotovoltaic) are evaluated thanks to representative models applied to four representative sites around the world. The evaluation is based on the ability to dispatch the power production throughout the year, the ability to maximize energy injection in the electrical grid, and the levelized cost of electricity. It is found that increasing the dispatchability of solar power plants will necessarily lead to the emergence of additional energy losses and important LCOE increase, either because of low round-trip efficiency of the storage system, or because of its high cost of energy capacity. Despite lower energy production for a given collecting area, combination of PV power plants with electrochemical storage or thermal energy storage surprisingly seem to be the most promising paths.