Hydrogen, as an emerging alternative fuel source, holds the potential to significantly contribute to California’s climate goals. Its carbon-free production using renewable electricity to split water into hydrogen and oxygen, known as ‘green’ hydrogen, offers a promising path towards reducing greenhouse gases.
However, hydrogen has never been implemented as a large-scale energy resource, and there is substantial uncertainty about the implications of expanding its role in the energy system. The lack of clarity on how much water will be required to meet hydrogen-driven demand is especially concerning to some, given the state’s dry, drought-prone climate and the need for water conservation and equitable drinking water access across the state.
A new report by the UCLA Luskin Center for Innovation, Exploring the Water Footprint of “Green” Hydrogen for Power Generation in California, examined the water footprint of green hydrogen production for power generation in California. The authors found that while green hydrogen has the potential to play a significant role in California’s renewable energy future, its water demands, costs, and local impacts are not well understood and raise substantial concerns, particularly for environmental justice communities. The report urges local and state leaders to proceed cautiously before fully committing to hydrogen as a climate solution.
California and the federal government have made substantial commitments to hydrogen, including a pending Biden Administration-era $7 billion “hydrogen hub” initiative — $1.2 billion of which is slated for California. The California hydrogen hub is led by the Alliance for Renewable Clean Hydrogen Energy Systems (ARCHES), a coalition of public and private stakeholders. While the future of federal energy policy is currently in flux with the Trump Administration, substantial investment in hydrogen as a fuel source is nonetheless expected. (The authors note that most of the report was written in 2024 and does not reflect the implications of the Trump administration’s 2025 actions.)
According to ARCHES resources, at least seven hydrogen production sites and 20 offtake sites will be located in Southern California. Modifications of the Scattergood Power Generation Station to utilize hydrogen are planned, as is the incorporation of hydrogen to reduce emissions of trucks and ships at the Los Angeles and Long Beach ports. Other known hydrogen projects in the Los Angeles region include Southern California Gas’ Angeles Link, the Lancaster Clean Energy Center, and the SGH2 Lancaster Project.
Large-scale hydrogen production poses significant challenges, particularly in California. Green hydrogen relies on water as a feedstock, and the amount necessary to produce a given amount of fuel varies, depending on the type of electrolyzer used, the source of the electricity, and the purity of the water source. Different energy sources require varying amounts of water for power generation, so the water cost of electricity generation used for electrolysis should be considered alongside the water quantity directly required for the electrolysis process. Water will also be needed for cooling; data on water use in methane turbines suggests that water withdrawals for hydrogen-fueled turbines will likely exceed current levels.
Once hydrogen is produced, it must be transported to where it will be used, which requires specialized pipelines and storage facilities. Most of this infrastructure does not exist today, so growing demand will necessitate both infrastructure expansion and investments in new storage facilities and retrofits to existing facilities.
SO HOW MUCH WATER?
Hydrogen technology is largely untested, and much of the information is considered proprietary and protected by nondisclosure agreements, so the authors note the analysis in the report is more conceptual than empirical, with many assumptions required.
The authors calculated scenario-based estimates using water requirements from the literature and public plans for hydrogen in California, which vary depending on type of electrolyzer and the source of electricity. The figure below shows the range of estimated annual water consumption for different annual hydrogen production levels.
The figure below compares the lowest water-use energy source to higher water-use energy sources and illustrates the critical role that the energy source for electrolysis will play in the water footprint.
ARCHES projects California’s hydrogen capacity will be approximately 17 million metric tons per year in 2045, which correlates to a range of 230,000 to 390,000 acre-feet of “very clean” water per year as a feedstock for electrolysis, depending on the electrolyzer used. For context, the statewide average annual water consumption between 1998 and 2015 was 39 million acre-feet, excluding environmental uses. Based on these numbers and the ARCHES projection of hydrogen demand, hydrogen production would account for 0.59% to 1% of water demand in 2045.
LOCAL IMPACTS IMPORTANT
While the estimated water use for hydrogen is relatively small, the impacts on communities where facilities are located might not be. Local water quantity considerations in hydrogen production and use may be considerable but have not yet been incorporated in local water system planning, so local water systems are primarily on their own for planning for hydrogen-related water demands. The treatment costs for the ultrapure water quality needed for hydrogen is achievable with existing treatment technologies, but the costs vary dramatically based on the treatment method used.
The costs of treating and securing safe water resources will likely be passed on to local water system customers, increasing affordability concerns. “From an equity perspective, the cost burden to provide clean water for hydrogen cannot fall onto the customers who are not responsible for the industrial practices that place new demands on their local water supplies,” the authors note.
Environmental justice advocates call for stringent standards, greater transparency, and community engagement to ensure hydrogen development does not exacerbate existing inequities.
CONCLUSION
The authors’ examination of existing information left many unanswered questions that must be addressed. Until more information and data become publicly available that demonstrate that green hydrogen can be implemented without mismanaging public resources and deepening environmental injustice, they urge state and local leaders to proceed with caution.
The report found that the overall impact on water quantity in the state will likely be minimal if hydrogen is produced outside of the state and some or all of the water use is offset by a reduction of the use of fossil fuels. In the long run, substituting green hydrogen for fossil fuel energy generation will likely decrease water use – if hydrogen is used to replace, rather than augment, existing energy supplies. The authors note that removing fossil fuels from the energy system is more than just adding renewable generation
However, the local effects, both within California and in other areas where hydrogen is being produced, could be substantial, especially if there is increased competition for local water resources. And hydrogen production’s reliance on ultrapure water also introduces high costs and significant quality demands that are considerable and should not be borne by local ratepayers. Environmental justice groups say hydrogen’s water needs cannot be prioritized over achieving the Human Right to Water in the state, which remains a challenge.
The report concludes, “Given the track record of ARCHES, there is reason to be concerned whether these considerations will be fully addressed. Therefore, the hydrogen industry bears the burden of proof to ensure transparency and accountability. Moving forward, meaningful changes in industry practices will be essential to address community concerns, uphold environmental justice principles, and ensure hydrogen is well understood before doubling down on it as a climate — much less a climate equity — solution.”
Q&A outlines concerns over Scattergood Modernization Project
The Scattergood Generating Station in El Segundo is currently a methane power plant owned by LADWP. LADWP has plans to convert Scattergood to burn a methane/hydrogen blend and hopes to eventually burn 100% hydrogen. The Scattergood Draft EIR evaluates the “Scattergood Modernization Project” which would retrofit the plant to be able to burn up to 30% hydrogen and 70% methane by 2029. This plan will soon go before the LADWP board for approval.
Below is a FAQ that outlines the community’s many concerns about this proposed project, which they say will continue to place significant pollution burdens on an already-overburdened community for decades to come. Groups including Sierra Club, the California Environmental Justice Alliance, Physicians for Social Responsibility – Los Angeles, Communities for a Better Environment, Los Angeles Waterkeeper, Food and Water Watch, and more all oppose LADWP’s proposed plan for Scattergood.
Scattergood Q+A April 2025
