Hydrogen Blending
Demonstration Project

This demonstration project will assess the feasibility of blending renewable 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 aims to inform a future hydrogen blending standard for California’s common carrier natural gas pipelines, prioritizing safety, system integrity, and reliability.

Replacing fossil fuels with carbon-free alternatives is a crucial step towards reaching the goal of carbon neutrality. The goal of SDG&E‘s project is 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 affecting typical equipment and materials found in California’s gas infrastructure. SDG&E will collect detailed data 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; community members; and environmental advocates.  

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

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

SDG&E will temporarily site hydrogen equipment on SDG&E property in Kearny Mesa, including  a fuel cell, a gas blending skid, and hydrogen storage tanks.

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. Pre-, during and post-project safety protocols include:

• A hydrogen system safety assessment, as well as hydrogen safety training for SDG&E personnel.
• Testing of existing and new leak survey equipment, as well as recurrent leak surveys.
• Equipment inspections.
• 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.

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 SDG&E real-world demonstration project has been modeled after these other successful evaluations and pilot projects. Furthermore, the data and information gathered from the project will help fill critical knowledge gaps essential for long-range decarbonization efforts. Hydrogen blending into California’s natural gas pipeline infrastructure can potentially accelerate the transition to using clean hydrogen as a fuel and energy storage medium, helping 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 many places, including Hawaii, Singapore, Canada, and others. Hawaii Gas has been safely blending hydrogen into its gas system since the 1970s.

Hydrogen used in this study will be produced via an offsite electrolyzer with a dedicated photovoltaic (PV) system.