Fig. 3: Electricity supply and demand at fixed export levels and increasing domestic CO₂ mitigation and vice versa with hourly temporal hydrogen regulation.

Panel a shows the electricity supply and demand at fixed export (1 TWh) and 0–100% domestic CO₂ mitigation. Increasing domestic CO₂ mitigation first phases out carbon-intensive coal generation in favour of combined-cycle gas turbines (CCGT), at medium to high domestic CO₂ mitigation the electricity system is fully renewable supported by flexibility through Vehicle-to-Grid (V2G) and sector coupling. Increasing electricity demands include Battery Electric Vehicles (BEV) and hydrogen (H₂) generation for other sectors. Panel b shows the electricity supply and demand at fixed domestic CO₂ mitigation (0%) and 1–120 TWh export. At increasing hydrogen exports the additional electricity required for hydrogen electrolysis is covered by onshore wind and solar photovoltaics (PV), as imposed by the temporal hydrogen regulation. See Supplementary Fig. 4 for electricity supply and demand if no hydrogen regulation is in place and Supplementary Fig. 9 for hydrogen exports up to 200 TWh. DAC direct air capture.