  Green hydrogen is expected to be traded globally in future greenhouse gas
neutral energy systems. However, there is still a lack of temporally- and
spatially-explicit cost-potentials for green hydrogen considering the full
process chain, which are necessary for creating effective global strategies.
Therefore, this study provides such detailed cost-potential-curves for 28
selected countries worldwide until 2050, using an optimizing energy systems
approach based on open-field photovoltaics (PV) and onshore wind. The results
reveal huge hydrogen potentials (>1,500 PWhLHV/a) and 79 PWhLHV/a at costs
below 2.30 EUR/kg in 2050, dominated by solar-rich countries in Africa and the
Middle East. Decentralized PV-based hydrogen production, even in wind-rich
countries, is always preferred. Supplying sustainable water for hydrogen
production is needed while having minor impact on hydrogen cost. Additional
costs for imports from democratic regions are only total 7% higher. Hence, such
regions could boost the geostrategic security of supply for greenhouse gas
neutral energy systems.
