Hydrogen from offshore wind: Investor perspective on the profitability of a hybrid system including for curtailment

Accommodating renewables on the electricity grid may hinder development opportunities for offshore wind farms (OWFs) as they begin to experience significant curtailment or constraint. However, there is potential to combine investment in OWFs with Power-to-Gas (PtG), converting electricity to hydrogen via electrolysis for an alternative/complementary revenue. Using historic wind speed and simulated system marginal costs data this work models the electricity generated and potential revenues of a 504 MW OWF. Three configurations are analysed; (1) all electricity is sold to the grid, (2) all electricity is converted to hydrogen and sold, and (3) a hybrid system where power is converted to hydrogen when curtailment occurs and/or when the system marginal cost is low, with the effect of curtailment analysed in each scenario. These represent the status quo, a potential future configuration, and an innovative business model respectively. The willingness of an investor to build PtG are determined by changes to the net present value (NPV) of a project. Results suggest that configuration (1) is most profitable and that curtailment mitigation alone is not sufficient to secure investment in PtG. By acting as an artificial floor in the electricity price, a hybrid configuration (3) is promising and increases NPV for all hydrogen values greater than €4.2/kgH2. Hybrid system attractiveness increases with curtailment only if the hydrogen value is significantly above the levelised cost of €3.77/kgH2. In order for an investor to choose to pursue configuration (2), the offshore wind farm would have to anticipate 8.5% curtailment and be able to receive €4.5/kgH2, or 25% curtailment and receive €4/kgH2. The capital costs and discount rates are the most sensitive parameters and ambitious combinations of technology improvements could produce a levelised cost of €3/kgH2.