The global push towards net-zero emissions by 2050 necessitates a significant increase in electrolytic hydrogen production using renewable sources like wind and solar power. However, this transition faces substantial technical, economic, and environmental challenges, particularly concerning the sustainable management of freshwater and land resources. Current hydrogen production heavily relies on fossil fuels (98% in 2020), primarily steam methane reforming (75%), with only 2% from water electrolysis. While alternative low-carbon methods exist (blue hydrogen, renewable natural gas, methane pyrolysis), they have limitations including biomass availability, carbon capture infrastructure needs, methane leakage, and CO2 capture rates. Electrolytic hydrogen offers a cleaner alternative, but its large-scale deployment raises concerns about land and water resource consumption for solar panels, wind turbines, and electrolyzers. Previous analyses often lack country-specific detail. This study addresses this gap by providing a country-by-country assessment of 2050 hydrogen demand and resource availability, considering different renewable energy penetration levels. The analysis combines spatially explicit data on solar and wind energy production yields with country-specific land availability data. By identifying countries facing resource constraints and potential hydrogen importers/exporters, this research contributes to the discussion on the geopolitical implications of a large-scale hydrogen economy. The study aims to provide reference cases disaggregating hydrogen demand by sector and country for 2020 and 2050, serving as inputs for future techno-economic analyses. This work is built upon previous research but adds a crucial layer of granular country-level detail.

Existing literature highlights the potential of electrolytic hydrogen in achieving net-zero emissions goals. Studies such as those by the International Renewable Energy Agency (IRENA) and the International Energy Agency (IEA) project a substantial increase in hydrogen demand by 2050. However, these projections often overlook the critical interplay between hydrogen production and the availability of land and water resources at a national level. Some research explores global land and water availability for hydrogen production, but lacks the fine-grained country-specific analysis needed for informed policy decisions. The existing literature recognizes the competition for land use between energy production and food production, as well as the environmental impacts of renewable energy infrastructure. The uneven distribution of water resources and the increasing global water demand are also highlighted as significant challenges. This research builds on this foundation, focusing on country-specific limitations to provide a more comprehensive understanding of the geopolitical and environmental implications of a large-scale hydrogen economy.

The methodology employed in this study involves several key steps. First, a reference scenario for hydrogen demand in 2050 (400 Mt/y globally) was established, disaggregating demand by country and sector (chemicals, cement, refineries, steel, transport). This was achieved by scaling 2020 energy consumption data based on projected population growth and sector-specific hydrogen usage. The chemical sector’s demand was projected based on ammonia and methanol production, using historical data from the IEA. Cement industry demand was determined proportionally based on country-level carbon emissions from the GID Database. Refinery demand was considered based on existing production capacity while transport sector demand was projected based on various scenarios reported in the literature. Second, spatially explicit and high-resolution data were used to determine the power production yield of solar and wind energy technologies. The energy yield calculation considered factors such as solar irradiation, wind capacity factor, and conversion efficiency. Grid cell data (0.75° × 0.75°) were used, excluding areas with protected status or high water stress. Third, the land area required for hydrogen production was calculated for each country by dividing the total hydrogen demand by the energy yield per unit area of solar and wind technologies. Fourth, an ecological footprint analysis assessed water requirements for manufacturing and operation of solar panels, wind turbines, and electrolyzers using data from existing literature. Finally, land and water scarcity were assessed in each country by comparing the required resources with available resources, considering different fractions of eligible land coverage (from 1% to 100%) to account for socio-political factors. The eligible land area was calculated by subtracting the area used for forests, agriculture, and urban areas, with different eligibility coefficients for each land cover type based on literature. The water availability was calculated by subtracting environmental flow requirements from renewable water resources, with environmental flow requirements assumed to be 80% of renewable water resources. Water scarcity was then evaluated by comparing water withdrawal (including hydrogen production) with water availability. Data sources for the analysis included FAOSTAT for land cover data, AQUASTAT for water resources data, IEA for energy consumption data, and the GID Database for cement industry emissions data. The analysis was performed using Python, with Matplotlib and Geopandas for data visualization.

The study's key findings revolve around the significant land and water resource implications of large-scale electrolytic hydrogen production. **Country-Specific Hydrogen Demand:** The per capita hydrogen demand is projected to increase substantially by 2050 compared to 2020 across most countries, especially in the chemical, transport, and steel sectors. Notable exceptions include Malaysia, South Korea, and the Netherlands, where the increase is more modest. **Land Requirements:** Depending on the 2050 hydrogen demand scenario (92–646 Mt/y) and the chosen renewable energy technology (solar or wind), land requirements vary considerably. For the reference scenario (400 Mt/y), the land requirement ranges between 0.09–0.6 million km² for solar panels and 1.9–13.5 million km² for wind turbines. Several countries, including Canada, Australia, Russia, Algeria, and Argentina, possess sufficient land for solar-based hydrogen production, even with low land coverage (≤1%), while other countries (South Korea, Japan) face significant land scarcity issues, especially with wind energy. **Water Requirements:** The overall global water demand for hydrogen production (13.6–95.6 billion m³ for solar and 3.2–22.6 billion m³ for wind) is relatively low compared to the total water withdrawals for other sectors (<3%). However, country-level analysis reveals significant water scarcity issues in several regions. Several countries, including Saudi Arabia, Algeria, Trinidad and Tobago, China, India, Egypt, Turkey, and South Korea, already experience significant water stress. Hydrogen production can exacerbate this stress in these regions. Trinidad and Tobago shows particularly high water requirements for hydrogen production. **Land and Water Scarcity:** The analysis of land and water scarcity reveals the following: (i) With 100% eligible land coverage, only Trinidad and Tobago faces land scarcity with solar power. Other countries face scarcity with wind power. (ii) With 5% land coverage, the number of countries facing land scarcity drastically increases and includes several European countries. (iii) Water scarcity primarily affects countries in the MENA region and some countries in South Asia and China; hydrogen production will worsen this situation. The combination of land and water scarcity poses considerable challenges for certain countries, particularly in Western Europe, Japan, the Dominican Republic, and South Korea. **Geopolitical Implications:** The study highlights the potential for a significant shift in the geopolitical landscape of the hydrogen market. Countries with abundant land and water resources such as those in Southern and Central-East Africa, West Africa, South America, Canada, and Australia are well-positioned to become major hydrogen exporters. Conversely, countries with high hydrogen demand but limited resources will likely need to rely on hydrogen imports.

The findings of this study highlight the intricate relationship between the ambitious goal of a global net-zero emissions future, the need for substantial electrolytic hydrogen production, and the limitations imposed by existing land and water resources. The significant variation in resource availability and hydrogen demand across countries underscores the need for a regionally nuanced approach to policymaking. The results demonstrate that while the global water demand for hydrogen production is relatively small in comparison to total water usage, several countries already facing water stress will experience an exacerbation of this situation with increased hydrogen production. This emphasizes the necessity of site-specific assessments of water resources before the implementation of any hydrogen production project. While the potential for land use in some regions appears substantial, it remains constrained by socio-political factors. Countries may need to carefully consider alternative strategies, such as relocating energy-intensive industries to regions with greater resource availability or enhancing the use of already available land to offset resource limitations. The study's regional variations in land and water limitations should significantly inform the development of international cooperation strategies for hydrogen trade and technological collaboration, thereby mitigating potential conflicts over resource allocation. The choice of renewable energy technology (solar vs. wind) can significantly influence the degree of resource scarcity. These findings also suggest a potential shift in global industrial landscapes.

This study provides a comprehensive country-level assessment of land and water resource limitations for large-scale electrolytic hydrogen production using wind and solar energy. While global water demand for hydrogen production is relatively small, it can exacerbate existing water scarcity in several regions. Land scarcity is particularly prominent in regions with high population density and limited eligible land for renewable energy infrastructure. The findings suggest that some countries with limited resources might need to rely on imports. Regions with abundant resources have the potential to become major hydrogen exporters. This research emphasizes the need for regional cooperation and strategic planning to ensure the sustainability of a large-scale hydrogen economy. Future research could focus on refining the demand projections by incorporating economic factors and more sophisticated land-use models. Further investigation could explore alternative technologies for hydrogen production and strategies to reduce land and water footprint.

This study makes certain assumptions that might influence the results. The projections of hydrogen demand are based on scaling current consumption values according to population growth, which doesn’t capture all economic factors that might affect industrial relocation or changes in consumption patterns. The analysis assumes that solar panels and wind turbines are produced within the country of use, not fully accounting for global supply chains. The choice of 80% of renewable water resources for environmental flows is based on existing literature but may not represent every context accurately. Finally, the analysis focuses only on onshore wind and solar power generation, neglecting other technologies such as nuclear, hydropower, and offshore wind, which could affect the overall land and water resource assessments.