Fig. 4: Optimization results for varying grid electricity prices.
a–d, The evaluation indices for the Renewable scenario (blue dash-dotted line) and the Mix scenario (blue solid line). For reasons of comparability, additional lines are included: the levelized cost of grey hydrogen produced by steam reforming as a function of the natural gas price (a) and the EI of grey hydrogen (b). EU, European Union unweighted average; GRC, Greece; GER, Germany; ESP, Spain; FRA, France. e,f, The added nominal power of the RESs (e) and the nominal electrolyser power and the annual full load hours (FLHa) of the electrolyser (f) in both scenarios. The chosen ___location for this analysis has a medium availability of renewables, which is represented by the potential yield for utility-scale PVs and onshore wind turbines in potential FLHa: 1,980 potential FLHa for onshore wind turbines and 1,036 potential FLHa for utility-scale PVs. The EIs of grid electricity for Greece, Germany, Spain and France can be found in the delegated act II (ref. 3). The covered hydrogen demand is 10,000 kg per day on average. An alternative visualization of the results as functions of the on-site hydrogen supply cost advantage of the Mix scenario over the Renewable scenario and a breakdown of the total cost in both scenarios can be found in Supplementary Figs. 3 and 4. All further technical and economical assumptions are summarized in Supplementary Tables 2–5. The calculation method for the levelized cost of grey hydrogen can be found in Methods.
