Photovoltaic–Electrolyzer System Operated at >50 mA cm−2 by Combining Large‐Area Shingled Silicon Photovoltaic Module with High Surface Area Nickel Electrodes for Low‐Cost Green H2 Generation

Abstract

Green hydrogen plays an important role in the energy transition as a renewable energy vector for long‐duration energy storage and as feedstock chemical for the industry. To reduce the price below 1.5 € kg−1 H2, competitive to production from fossil fuels, silicon photovoltaic (PV)‐powered efficient anion‐exchange membrane (AEM) water electrolysis is a promising combination. Practical implementation of such a photovoltaic–electrolyzer (PV–EC) technology requires standard area‐sized solar cells and electrolyzers operating at large current densities. Nonetheless, state‐of‐the‐art research often employs <10 cm2 PV devices and electrolyzers operated at <10 mA cm−2. Herein, a commercially relevant PV–EC system combining shingled standard silicon technology with efficient low‐cost AEM electrolysis using high‐surface‐area (26 m2 cm−3) nickel nanomesh electrodes is presented. The produced H2, operating current, and voltage are in situ monitored over >20 h yielding a stable solar‐to‐hydrogen efficiency (ηSTH) of 10% at electrolyzer current densities ≈60 mA cm−2 and dynamic load testing up to 300 mA cm−2 results in stable performance. Based on the measured PV–EC system data, best practices to accurately determine the ηSTH for PV‐powered water‐splitting devices and the validation of this benchmark against important component parameters for practical implementation of this technology are discussed.