Development of a concentrator photovoltaic-electrochemical system for water splitting with waste heat integration

Abstract

As the world shifts towards reducing fossil fuel usage and achieving global climate goals, green hydrogen is emerging as a key factor to the energy transition, serving not only as a versatile chemical for various industrial processes but also as a CO2-neutral fuel and energy vector. A promising approach to producing hydrogen from solar energy involves harnessing electricity from photovoltaic (PV) cells to power electrolyser cells (ECs), which yield hydrogen via water splitting. Industrial photovoltaic-electrochemical (PV-EC) setups usually combine solar fields with large centralised EC stacks. However, research trends show that PV-EC systems can achieve higher efficiencies when adapted to operate under concentrated sunlight. These concentrator photovoltaic-electrochemical (CPV-EC) systems require active cooling due to the high irradiance the PV is exposed to and the fact that most commercial water electrolysers are designed to operate above their thermoneutral voltage, where they also generate excess heat. The present work focuses on the development of a CPV-EC solar-to-hydrogen system, which will be designed for use in conjunction with solar concentrators. In addition to CPV modules and a water electrolyser, this particular system will include a thermally coupled process (TCP) intended to increase the overall efficiency by integrating the waste heat in the cooling streams back into the process. The objective of this study is to develop and evaluate concepts of potential CPV-EC-TCP systems with the aim of identifying, modelling and then experimentally characterising a promising system choice.