A new solar to hydrogen conversion system with high efficiency and flexibility

Abstract

Solar-to-hydrogen energy conversion is a promising technology because it enables high-capacity, long-term storage of solar energy. We propose a new highly efficient solar-to-hydrogen conversion system consisting of multiple converter-electrolyzer sets connected in parallel to a photovoltaic (PV) array. This system is flexible to apply to various PV configurations. One-day simulations based on measured PV and electrolyzer characteristics demonstrate very high maximum power point tracking (MPPT) efficiency (higher than 99.9%) and average power conversion efficiency (94.0%) on a clear sunny day. Annual energy production is expected to increase by 8.5%-point compared with a single converter system using one of the best commercial converter. The key elements of the high efficiency are the new system topology, a specially designed phase-shift full-bridge converter and a control method “P&O with converter scoring” algorithm.