Wind turbine power fluctuation test protocol for proton exchange membrane water electrolysis

Abstract

This study investigates the laboratory implementation of operating a catalyst coated proton exchange membrane water electrolyzer with a fluctuating wind turbine power supply. A detailed method to determine typical wind power conversion for electrochemical water splitting is provided and summarized as a repeatable and scalable electrical power fluctuation test protocol. It contains an annual wind speed distribution as a reference day of wind turbine power supply. To check the reproducibility of the reference day operation, this performance test protocol is carried out isothermally at 80 °C, isobarically at 1 atm, and galvanodynamically at intervals of 10 s. The specified power supply is compared with the actual measured power flow through the electrolyzer cell. Subsequent operation phenomena, like hydrogen impurities within the oxygen stream, are evaluated. To learn more about the reproducibility of the fluctuation effects on performance, the test protocol is run five times on comparable single cell setups and fluctuation intensities. To gain general knowledge about the impact of fluctuating power supply, one additional constant test protocol is run at the average current density of the wind turbine derived test protocol. Complementary condition monitoring by polarization curves returns indicators about the voltage efficiency of the cell components. The electrochemical condition is observed at the beginning, the middle, and the end of test. The current efficiency is monitored as well. The phenomenological description of the fluctuation-dependent performance change provides a summary of the reproducible effects of wind power supply on electrochemical cells during their initial four days of operation.