Concentrated photovoltaic electrochemical cell (CPEC): A route toward high-efficiency, cost-effective solar hydrogen production

Solar hydrogen production is one of the most re-quired technologies for the realization of sustainable energy sys-tems which is independent of fossil fuel. The solar-to-hydrogen (STH) energy conversion efficiency for photocatalysts, which have been studied quite intensively for decades, remains much lower than 10%. The combination of photovoltaic and electrochemical cells, on the other hand, can easily achieve the STH efficiency over 10%. We here present the field demonstration of a system combin-ing a concentrator photovoltaic (CPV) module and polymer elec-trolyzers, which led us to the STH efficiency of 17.1%. A method will be presented to optimize the series/parallel connection be-tween CPV and electrolyzers for maximizing the STH, which pre-dicts 28% STH when 35%-efficient CPV module is used.