Stable Electrolytic Hydrogen Production Using Renewable Energy

Abstract

Hydrogen electrolysis will be an integral technology to any future hydrogen economy. However, the inherent intermittency of upstream solar and wind power results in a fluctuating hydrogen output, which is incompatible with the feedstock requirements of many downstream storage and utilisation applications for hydrogen. Suitable backup power or hydrogen storage strategies are thus needed in system design. In this work, we conduct technoeconomic modelling to design electrolytic production systems featuring stable hydrogen output for various locations across Australia. The modelling simultaneously considers the levelised cost of hydrogen (LCOH), emissions intensities and annual capacity factors. Location specific temporal weather data is used to determine the solar and wind power profiles across a typical meteorological year and hence the electrolytic hydrogen generation profile. We demonstrate achievement of a stable hydrogen supply by imposing annual capacity factor requirements on the system. This forces the system modules (i.e. solar, wind, electrolyser and hydrogen storage) to be oversized in order to achieve the desired capacity factor. Maintaining a reliable hydrogen supply can be achieved by imposing a high-capacity factor threshold whilst using the grid for the remaining small fraction of generation. Such a design costs approximately 15% more on average than using a system which is optimised for cost alone.

Keywords: Hydrogen, Electrolyser, Renewable energy, technoeconomic, reliability