Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30%

Hydrogen production via electrochemical water splitting is a promising approach for storing solar energy. For this technology to be economically competitive, it is critical to develop water splitting systems with high solar-to-hydrogen (STH) efficiencies. Here we report a photovoltaic-electrolysis system with the highest STH efficiency for any water splitting technology to date, to the best of our knowledge. Our system consists of two polymer electrolyte membrane electrolysers in series with one InGaP/GaAs/GaInNAsSb triple-junction solar cell, which produces a large-enough voltage to drive both electrolysers with no additional energy input. The solar concentration is adjusted such that the maximum power point…

• NS
  National Science Foundation

  Award: 1433442
• UD
  U.S. Department of Energy
• OO
  Office of Energy Efficiency and Renewable Energy
• DO
  Division of Graduate Education
• DO
  Division of Chemical, Bioengineering, Environmental, and Transport Systems

  Awards: 1433442, CBET-1433442
• OO
  Office of Energy Efficiency