title: Solar water splitting by photovoltaic-electrolysis with a solar-to-hydrogen efficiency over 30.
abstract: 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 of the photovoltaic is well matched to the operating capacity of the electrolysers to optimize the system efficiency. The system achieves a 48-h average STH efficiency of 30%. These results demonstrate the potential of photovoltaic-electrolysis systems for cost-effective solar energy storage.
authors: Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, California 94305, USA.
authors: Jieyang
authors: 0000-0002-4878-6386
authors: J
authors: Jia
authors: Department of Chemical Engineering, Stanford University, 443 Via Ortega, Shriram Center Room 305, Stanford, California 94305, USA.
authors: Linsey C
authors: LC
authors: Seitz
authors: Department of Chemical Engineering, Stanford University, 443 Via Ortega, Shriram Center Room 305, Stanford, California 94305, USA.
authors: Jesse D
authors: JD
authors: Benck
authors: Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, California 94305, USA.
authors: Yijie
authors: Y
authors: Huo
authors: Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, California 94305, USA.
authors: Yusi
authors: Y
authors: Chen
authors: Department of Chemical Engineering, Stanford University, 443 Via Ortega, Shriram Center Room 305, Stanford, California 94305, USA.|Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, Jurong Island 627833, Singapore.
authors: Jia Wei Desmond
authors: JW
authors: Ng
authors: Solar Junction, 401 Charcot Avenue, San Jose, California 95131, USA.
authors: Taner
authors: T
authors: Bilir
authors: Department of Electrical Engineering, Stanford University, 350 Serra Mall, Stanford, California 94305, USA.
authors: James S
authors: JS
authors: Harris
authors: Department of Chemical Engineering, Stanford University, 443 Via Ortega, Shriram Center Room 305, Stanford, California 94305, USA.
authors: Thomas F
authors: TF
authors: Jaramillo