[ green DRI ]
Fig. 2. Annual production rate( solid line) of green hydrogen as a function of RES installations and electrolyzer output in Spain. Red line: annual hydrogen required for continuous operation of a 1 Mt DRI plant. 2, 3, 4 Dashed lines: maximum hydrogen production assuming 8,760 operating hours per year at full capacity. Bold lines and areas: green hydrogen production based on weather conditions. The grey area represents hydrogen produced from non-intermittent sources, such as thermally generated power or natural gas used to produce reducing agents.
installation, and BESS ratings of 200 MW, 400 MW, 600 MW, and 800 MW – with capacities of 2 h, 4 h, 6 h, or 8 h. Costs were normalized to publicly available data from NREL for wind, solar, and BESS 6, and extrapolated to 2030 according to the moderate scenario. Hydrogen electrolyzer costs were based on data from the European Hydrogen Observatory, 7 valid for utility-scale installations, with adjustments for local price corrections and taxes.
As BESS costs decrease significantly with increasing capacity, these variations were considered. Other long-duration storage systems – such as compressed air energy storage or redox flow batteries – should also be evaluated based on project location. The prices used in this study are defined in Table 2. Given calculation accuracies and the current currency exchange rate, the conversion from USD to EUR is assumed to be unity.
Results and discussion
The RES power generation profile was evaluated hourly, with an average hydrogen production calculated at 18 ± 1 kg H / MWh, assuming 360
2
MW of electrolyzer capacity. The sensitivity
study results for Spain are shown in Figure 2. The hydrogen demand of 53,404 t H 2 is indicated by the red line. 2, 3, 4 Bold lines represent green hydrogen production and hydrogen from other power sources. The diagrams on the right show annual RES generation curves for 500 MW, 1,000 MW, and 1,500 MW, with green lines for RES, purple for electrolysis based on green power, and grey for hydrogen from other sources. Hydrogen production is based on hourly RES generation for the three cases during the week of 25 – 31 January 2019.
With 500 MW of RES, the green hydrogen share is 37.6 %( 17 kg H / MWh) or 42. 1 %( 18 kg H /
2 2
MWh). For 1,000 MW, it is 63.5 % or 71.0 %, and
for 1,500MW, it is 73.2 % or 81.8 %. The remaining hydrogen must be produced from non-RES power or within the steel plant using natural gas.
The full decarbonization of the DRI process requires green power. During periods of low
Table 2. Specific solution costs for the installations within the energy system. 6, 7 Values are extrapolated to 2030 according to the moderate scenario.
PV [$/ kW ]
Onshore Wind [$/ kW ]
BESS [$/ MWh ]( 2 h / 4 h / 6 h / 8 h)
Electrolyzer [$/ kW ]
1,160 1,408 269 / 198 / 183 / 177 2,400
Hydrogen Tech World | Issue 21 | April 2025 27