UC San Diego Hydrogen Blending Project

This demonstration project will assess the feasibility of blending renewable, carbon-free hydrogen into the natural gas distribution system to help achieve regional and state decarbonization and climate goals. ​ In Decision 22-12-057 December 15, 2022, the CPUC directed the Joint Utilities to propose system testing through demonstration projects on the effects of hydrogen blended into natural gas systems at concentrations up to 20% by volume. The collective work of the Joint Utilities through these demonstration projects will be intended to help inform a future hydrogen blending standard for California’s common carrier natural gas pipelines that prioritizes safety, system integrity, and reliability.

Replacing fossil fuels with carbon-free fuels is a crucial step towards reaching the goal of carbon neutrality. UC San Diego and SDG&E are collaborating on this project to demonstrate that hydrogen can be safely and effectively blended into the natural gas distribution system resulting in reduced consumption of fossil fuels and greenhouse gas emissions.

The project will assess the amount of hydrogen (up to a maximum of 20% by volume) that can be blended into the natural gas stream without any impact on typical equipment and materials found in California’s gas infrastructure. Detailed data will be collected by SDG&E regarding operational performance and impact on materials.

Hydrogen (H2) is a carbon-free, gaseous energy carrier. Through the process of electrolysis (splitting water into hydrogen and oxygen) resulting hydrogen can be injected into the existing natural gas pipeline infrastructure, and the resulting gas blend can be used to generate heat and power with lower emissions than using natural gas alone.

SDG&E recognizes the critical importance of stakeholder and community engagement around novel hydrogen projects such as blending. To date, SDG&E has engaged and coordinated with many stakeholders connected to the proposed Project, including the California Public Utilities Commission’s (Commission) Energy Division; UCSD staff, faculty, and students; and environmental advocates.  will be coordinated in conjunction with UC San Diego throughout all phases of the project to ensure communications are timely, meaningful, and address concerns.

The SDG&E Project Team will coordinate with relevant community-based organizations for further project engagement. There is the potential for community-based organizations to be compensated for their participation in this work. If you are a community-based organization that is interested in partnering on engagement or if you have any questions related to our engagement plan, please reach out to [email protected].

An amended joint application will be filed by March 1, 2024. Project development will begin upon CPUC approval.

SDG&E will temporarily site hydrogen equipment on campus, including an electrolyzer to produce clean hydrogen from water and renewable energy, a gas blending skid, and a hydrogen buffer tank.

The specifications for the planned equipment have undergone rigorous audits by SDG&E, ensuring they meet required national and international hydrogen safety and operational standards.*

Further, a safety assessment for all hydrogen equipment will be conducted by an external hydrogen safety consultant during the planning and design phase of the initiative.

After the project is completed, this equipment will be removed, and the site will be restored to its original condition.

* International standard for hydrogen generators using water electrolysis; National Fire Protection Association standard for hydrogen safeguards for the generation, installation, storage, piping, use, and handling of hydrogen in compressed gas form.

Project safety is the top priority. We do not anticipate any changes to current UC San Diego safety and emergency practices. Pre-, during and post-project safety protocols include:

• A hydrogen system safety assessment, as well as hydrogen safety training for SDG&E personnel, campus fire marshal, and other relevant UC San Diego campus personnel conducted by independent third parties specializing in hydrogen safety.
• Testing of existing and new leak survey equipment and recurrent leak surveys by SDG&E.
• Equipment inspections by SDG&E.
• Gas system operational and equipment tests, meter replacements, and other operational activities that SDG&E performs in a natural gas distribution system.

Any additional project-specific protocols and emergency response plans will be developed and disseminated in advance of the project.

Earthquake and wildfire hazards have been considered, and the equipment will meet appropriate standards related to these risks.*

* Seismic codes of the International Building Codes and California Building Codes; American Society of Mechanical Engineers codes and standards for hydrogen service; National Fire Protection Association standard for the storage, use, and handling of compressed gases and cryogenic fluids in portable and stationary containers.

No, but it will be the first in San Diego.

The blending of up to 20% hydrogen into natural gas has been previously demonstrated by SoCalGas in end-use appliances at the H2 Innovation Experience and laboratory testing. Blending within a university’s gas distribution system has previously been demonstrated with great success in the UK with a trial at Keele University.

This UC San Diego-SDG&E real-world demonstration project has been modeled after these other successful evaluations and pilot projects. Further, the data and information gathered from the project will fill important knowledge gaps toward long-range decarbonization efforts. Hydrogen blending into California’s natural gas pipeline infrastructure can potentially help accelerate the transition toward the use of clean hydrogen as a fuel and energy storage medium, and help the state meet climate and air quality goals. 

This project builds on the latest research: The Hydrogen Blending Impacts Study commissioned by the California Public Utilities Commission and performed by UC Riverside. The study recommends utilities conduct “real world” demonstrations utilizing the actual natural gas infrastructure with 5-20% hydrogen gas blends over extended periods to assess the effect of hydrogen on materials, components, facilities, and equipment through California’s infrastructure. Additionally, hydrogen and natural gas blends are safely used in Hawaii, Singapore, Germany, France, Belgium, the United Kingdom, Italy, and others. Hawaii Gas has been operating a steel transmission line containing a 10-12% blend of hydrogen since the early 1970s. 

Hydrogen used in this study will be produced on site via a dedicated, grid-connected electrolyzer (splitting water to produce hydrogen and oxygen)