Many have hailed “green” hydrogen as a versatile, carbon-free alternative to fossil fuels. However, environmental justice advocates, academics, and others have raised concerns about its equity and justice implications, including its water footprint in drought-prone California.

Producing green hydrogen requires substantial amounts of highly purified water, a scarce and costly resource in the state. Despite growing investments in hydrogen infrastructure, there is limited public data on project locations, water sourcing, and purification costs, making it difficult to fully assess the local and regional impacts. This lack of transparency raises concerns about potential risks to water security, affordability, and environmental justice.

This study examines hydrogen’s water footprint in California, with a focus on hydrogen combustion for power generation. We analyzed publicly available data, reviewed scientific literature, and estimated hydrogen’s potential water demands under different production and energy scenarios.

Key findings include:

• • High Treatment and Infrastructure Costs: Purifying water to the ultrapure standard required for electrolysis introduces significant costs and could strain local water utilities.
  • Lack of Transparency in Hydrogen Planning: Limited publicly available information makes it difficult to assess water sourcing, environmental risks, and potential impacts on drinking water supplies.
  • Large-Scale Water Demand: Our back-of-the-envelope calculations suggest that California’s projected hydrogen production will require between 230,000 and 390,000 acre-feet of high-quality water annually by 2045. While this represents a modest impact statewide, the local effects could be significant, particularly in water-stressed regions.

Despite increasing federal and state investments in hydrogen, many unanswered questions remain. To fully understand the on-the-ground impacts, further transparency is needed regarding project locations, water sources, source quality, and purification methods. Without this information, there is no guarantee that hydrogen can be implemented without mismanaging public resources or exacerbating environmental injustices.

Broader Equity Implications and Principles for Hydrogen’s Water Impact in California

To ensure hydrogen development does not compromise the state’s water security and equity goals, our research leads us to highlight the following tasks for energy decision-makers in the state, echoing many of the considerations voiced by advocates in written comments:

• Protect community water access by ensuring hydrogen production does not divert resources from communities already struggling with safe, affordable drinking water.
• Increase transparency and accountability by requiring hydrogen proponents to disclose project details, including water sourcing, purification costs, and environmental impacts.
• Prioritize electrification over hydrogen whenever feasible, reserving green hydrogen for applications where electrification is not a viable alternative.
• Ensure hydrogen production only uses surplus renewable energy and water supplies, preventing competition with essential community water needs.
• Implement stringent safety and environmental standards for hydrogen storage, transportation, and combustion to prevent leaks, explosions, and air quality hazards.

Hydrogen decision-makers bear the burden of proof to demonstrate that green hydrogen can be implemented responsibly, without deepening environmental injustices. Local and state leaders must proceed with caution, ensuring that hydrogen policies protect public resources, water security, and community well-being.

See LCI’s website to learn more about our research initiatives on local water supply and renewable energy.