purchases make this development possible. Excess electricity in electricity systems with a high share of 80 to 100 per cent renewable energies (case A in Figure 2) ensures that electrolysers consume electricity that could otherwise not be marketed (see Energy Brainpool time series analyses). This reduces electricity procurement prices. Further conceivable scenarios would be a supplementary payment of fixed electricity price components for flexibly consumed excess electricity (case B in Figure 2) or the case of off-grid electrolysis gas farms (based on a current study commissioned by Agora Energiewende). This is shown in case C in Figure 2. The latter cases are less efficient or systemic than case A utilising the excess electricity and might significantly reduce the competitiveness of electrolysis gas.
From the mid-2030s, the production of electrolysis gas can be cheaper than the purchase of fossil natural gas (natural gas + CO2-certificates), as evaluations show . The prerequisites for this are cost degression for electrolysers through continuous investment in the technology, low electricity procurement costs for the otherwise curtailed excess electricity, the achievement of climate protection targets and the targeted share of renewable energies.