Hydrogen production using curtailed electricity of firm photovoltaic plants: Conception, modeling, and optimization

A firm photovoltaic (PV) plant differs from a conventional unconstrained PV plant in terms of its ability to satisfy load demand on a 24/365 basis. Amongst various firm power enablers, overbuilding & proactive curtailment is the most counter-intuitive yet indispensable one. Although the cost-effectiveness of firm PV plants has been studied numerous times, few studies have evaluated the utilization of curtailed energy. To that end, this work advocates using the curtailed energy for hydrogen production, which is not impacted by the intermittency and variability of the curtailed power. A new mathematical optimization model that minimizes the firm kWh premium of the PV–battery–hydrogen hybrid system is put forth. Instead of using just generic modeling for the energy components (i.e., PV, battery, and electrolyzer), refined modeling, which could introduce bilinearity and nonlinearity, is herein considered. To address such optimization difficulty, a new algorithm, which hybridizes the particle swarm optimization and the branch-and-bound method, is proposed. The analysis reveals that the additional inclusion of a hydrogen production system within a firm PV plant is techno-economically attractive, and can lower the curtailment rate by 36%, and the overall firm kWh premium by almost 7%. What this implies is that, under the current market economics, the hydrogen production system becomes entirely free when used with firm PV plants.