“This is an unprecedented time in history for hydrogen with interest being amplified worldwide due to its potential to address the climate crisis as well as energy security and resiliency. Though there are significant challenges, zero and low-carbon hydrogen can be a key part of a comprehensive portfolio of solutions to achieve a sustainable and equitable clean energy future. And the United States is stepping up to accelerate progress through unprecedented investments in clean energy.” ~U.S. Department of Energy, DOE National Clean Hydrogen Strategy and Roadmap
Solving the current climate crisis will take thoughtful planning, sustained dedication, and some good old-fashioned luck. Some potential climate solutions are huge game changers, while many are smaller in scale. Some ideas will come to us fully developed and ready to implement. Others will start small and evolve to become more influential as we make progress against our emission reduction goals.
One large area that is ripe for development over the upcoming decade is the production of emissions-free hydrogen to either power fuel cells or for use in energy storage systems. Until this point, hydrogen has not been a central focus of work here in Sonoma County, and we have focused much more on the purchase of electric vehicles and the installation of EV charging equipment. Compelling use cases for hydrogen can be found in aviation, shipping vessels, freight and passenger rail, facility operations, industrial processes, and light-duty and heavy-duty vehicles.
State and Federal Guidance
To start with a slightly larger context, the State of California considers itself technology-neutral and actively supports all viable options to reach zero emissions. These options include, but are not limited to, battery-electric and hydrogen fuel-cell electric across all vehicle sizes and classes. To help meet statewide zero-emission goals, California has pledged to work with the private sector and all appropriate levels of government to spur the construction and installation of 200 hydrogen fueling stations by 2025. As of November 2022, just over 60 stations across the state offer retail service for light-duty vehicles, with approximately 22 stations in the nine-county San Francisco Bay Area and only one in the North Bay. Thirty-four more are in the planning stages, with proposed stations in Novato (Marin County) and Santa Rosa currently in the permitting process. Additionally, Rohnert Park has been approached about adding hydrogen fueling at existing gas stations. There are also seven existing stations for heavy-duty vehicles (HDV) in the state, with at least four more planned for the future.
The Federal government has also made developing hydrogen fueling sources a top priority. The U.S. Department of Energy has recently allocated up to $8 billion from the Bipartisan Infrastructure Law for hydrogen-related projects. A large amount of this funding is designated for developing Regional Clean Hydrogen Hubs to create networks of hydrogen producers, consumers, and local connective infrastructure to accelerate the use of hydrogen as a clean energy source. There are multiple efforts working to secure funding for at least one Clean Hydrogen Hub in California. If a Bay Area location is chosen, Sonoma County would have access to this fuel source and be able to expand clean hydrogen fueling to the north.
To be truly emission-free battery-electric and hydrogen fuel cell electric vehicles (FCEVs) require zero-emission electricity. Battery-electric vehicles use electricity to charge their batteries, while the zero-emission production of hydrogen at scale for later use in FCEVs also requires large amounts of electricity to power the process. Access to this renewable electricity will be one of the major limiting factors for the operation of large-scale zero-emission fleets, whether these be hydrogen fuel cell electric vehicles or battery-electric vehicles.
When compared with battery-electric vehicles, hydrogen fuel cell vehicles do have several key benefits:
- Hydrogen fuel cell vehicles can carry more passengers/freight per volume due to the lack of heavy batteries. This weight reduction allows manufacturers to increase passenger space and vehicle range when EVs cannot.
- The time needed to refuel hydrogen is dramatically quicker than recharging batteries and is much closer to the time that an average customer expects for vehicle refueling. For battery-electric vehicles, DC Fast Chargers are the fastest way to charge currently. However, these chargers still take longer than hydrogen fueling and require a large amount of high-demand electricity that must be ready and available for use at a moment’s notice.
- Heavy metals are used in hydrogen fuel cells and lithium-ion batteries. The metals used for converting hydrogen to electricity are in the cathode but are not needed for fuel storage. This allows hydrogen-based systems to scale without a continuing need for large inputs of heavy metals. In contrast, electric vehicles require large inputs of heavy metals for both usage and storage mechanisms.
- Long-duration hydrogen storage also offers the potential to offset energy production and use the resultant electricity at different times of the year. If stored securely, hydrogen does not degrade or lose power density over time. In contrast, lithium-ion batteries used in electric vehicles are better suited for short-term storage under 10 hours before discharge losses begin to reduce efficiency.
Hydrogen Production and Distribution
When zero-emission electricity is used to produce hydrogen from water, the resultant product is referred to as “green hydrogen.” Unfortunately, most currently available hydrogen is produced from non-renewable methane gas feedstock and cannot be considered zero-emission. This product is commonly known as “grey hydrogen.” More details about various production methods can be found below:
Electrolysis (Water Splitting)
- Electrolysis uses electricity to split water into hydrogen and oxygen. Hydrogen produced in this fashion can result in zero greenhouse gas emissions, depending on the source of the electricity used.
- Unfortunately, several major limitations must be overcome before 100% zero-emission hydrogen can be produced at scale. Research is underway to improve the electrical intensity of the process to make it comparable to using electricity directly in electric vehicles. Additionally, work is being undertaken to reduce the production cost significantly compared to more mature carbon-based methods such as natural gas reforming.
Natural Gas Reforming / Steam Methane Reformation (Fossil Resources)
- Approximately 95% of the hydrogen produced today in the United States is made via steam-methane reforming in which high-temperature steam (700°C–1,000°C) is used to produce hydrogen from a methane source, such as natural gas. A secondary water-gas shift reaction is then used to create additional hydrogen from the waste products.
- Even with the upstream process of producing hydrogen from natural gas and delivering and storing it for use in vehicles, the total greenhouse gas emissions from a fuel cell vehicle are cut in half and petroleum is reduced by over 90% compared to today’s gasoline vehicles.
Biomass Gasification (Biomass/Waste)
- Gasification is a process that converts organic biomass at high temperatures (>700°C) into carbon monoxide, hydrogen, and carbon dioxide. The feedstock used can include many different forms of renewable organic resources, such as agricultural crop residues, forest residues, fast-growing crops grown specifically for energy use, organic municipal solid waste, and animal wastes.
Hydrogen Distribution Options
- For use as a transportation fuel, hydrogen is usually compressed into a smaller volume, stored in tanks, and trucked to destinations. Compressing hydrogen into smaller volumes for later use is energetically expensive. Due to its small molecular size, hydrogen is also especially prone to leakage and can cause indirect warming when released into the atmosphere.
- Both hydrogen-only fuel providers and owners of existing fossil-fueling stations are investigating the addition of hydrogen fuel pumps throughout California. For municipal agencies considering hydrogen fuel for fleet use, co-locating services for publicly owned heavy-duty vehicles alongside consumer-facing services for light-duty vehicles can allow a single site to serve both purposes.
Both battery-electric and hydrogen fuel cell vehicles are viable pathways to reduce greenhouse gas emissions, and both require major investments in infrastructure to succeed. While the light-duty vehicle market is currently dominated by electric vehicles and much focus is being given to developing a statewide electric charging network, hydrogen fuel cells are well positioned for use in heavy-duty vehicles and several other hard-to-decarbonize industries. Specific focus will need to be given to improving the efficiency of the electrolysis process, ensuring a reliable source of zero-emission electricity, and balancing the investments in battery-electric and hydrogen fuel cell transportation networks. As opportunities arise and funding becomes available, Sonoma County has the potential to expand the clean hydrogen fueling system northward in alignment with state and federal climate goals to dramatically reduce greenhouse gas emissions.
This blog post is based on a research paper written by RCPA to educate our members and partners throughout Sonoma County on some of the issues surrounding using hydrogen in zero-emission vehicles. You can read the full research report on the RCPA website here: https://rcpa.ca.gov/rcpa-research-report-hydrogen-fueling-for-zero-emission-vehicles-final-2022-11-21/
Additional resources for further reading are included below:
Hydrogen Fueling – Tools and Resources
- Bay Area Air Quality Management District (BAAQMD)
- California Air Resources Board (CARB)
- AB 32 Climate Change Scoping Plan Home Page
- Draft 2022 Scoping Plan Update
- Low Carbon Fuel Standard Electricity and Hydrogen Provisions
- 2022 Annual Evaluation of Fuel Cell Electric Vehicle Deployment and Hydrogen Fuel Station Network Development
- Hydrogen Station Network Self-Sufficiency Analysis Report 2021
- Drive Clean – Hydrogen Fueling Overview
- Governor’s Office of Business and Economic Development (GO-Biz)
- U.S. Department of Energy (DOE)
- California Council on Science and Technology (CCST)
- Rocky Mountain Institute (RMI)
- Additional Resources
- TED Talks: Vaitea Cowan – How green hydrogen could end the fossil fuel era
- Conserve Energy Future: Advantages & Disadvantages of Hydrogen Energy
- Pirelli: Hydrogen as a fuel – the pros and cons
- CalStart: Best Practices in Hydrogen Fueling and Maintenance Facilities for Transit Agencies
- Utility Dive: Sempra Energy hydrogen pipeline, blending proposals face opposition at the California PUC
- International Consortium for Fire Safety, Health, and the Environment: Safety issues regarding fuel cell vehicles and hydrogen fueled vehicles