Improving the utilization factor of a PEM electrolyzer powered by a 15 MW PV park by combining wind power and battery storage – Feasibility study

Abstract So far, the biggest photovoltaic park in Belgium has been injecting all its energy into the electric distribution grid through a power purchase agreement with an electricity supplier. Due to decreasing and volatile wholesale electricity prices, the industrial partners/owners of the photovoltaic park are considering hydrogen storage in an attempt to increase the value proposition of their renewable energy installation. A major objective of the present work is to show how the utilization factor of the electrolyzer is affected by the design of the power supply system when the latter consists only of renewable energy sources instead of using the electric grid. Different hybrid designs were developed, by combining the existing photovoltaic source with wind power and state-of-the-art energy storage technologies (Vanadium Redox Flow or Lithium NMC). Finally, four scenarios were investigated, all considering a 1 MW PEM electrolyzer: A) 15 MW PV, B) 15 MW PV, 2MW Wind, C) 15 MW PV, 2 MW Wind, Battery, D) 15 MW PV, 15 MW Wind. The utilization factor was found as follows, for each scenario respectively: A) 41,5%, B) 65,5%, C) 66,0–86,0%, D) 82,0%. Furthermore, the analysis was extended to include economic evaluations (i.e. payback period, accumulated profit), specifically concerning scenario B and C. The results of this study lead to a number of conclusions such as: i) The utilization of the electrolyzer is limited when its power supply is intermittent. ii) Compared to PV, wind power makes larger contribution to the increase of the utilization factor, iii) 100% utilization can be achieved only if an energy storage system co-exists. iv) With a utilization factor at 65,5% scenario B can deliver a payback period in less than 8 years, if hydrogen is sold above 5€/kg. An analytic overview of all conclusions is presented in the last section of the paper.