Southern California Gas Co. (SoCalGas), along with San Diego Gas & Electric Company and Southwest Gas Corporation, on Tuesday submitted a petition to the California Public Utilities Commission (CPUC) to modify a 2022 decision ordering the California investor-owned gas utilities (IOUs) to develop a demonstration project blending up to 5% hydrogen into natural gas prior to recommending a systemwide clean renewable hydrogen injection standard for medium pressure distribution systems.

Because the safety case for low‑level blends has been advanced since the CPUC's order, the utilities are asking the agency to remove the requirement to develop the 5% demonstration projects before recommending a systemwide blending standard. The petition does not change the CPUC's requirement for utilities to develop demonstration projects studying blends in the 5%–20% range, which remain an important part of California's long‑term decarbonization planning.

Since 2022, a significant body of new research, operational data, and real‑world experience has emerged. Utilities in America – including in California – and around the world have already demonstrated that blending up to 5% hydrogen into existing natural gas systems can be done safely, reliably, and without modifying customer appliances.

"Building off what we've learned collectively over the past few years, the CPUC has an opportunity to save ratepayers both money and time as we work to help California scale hydrogen production and decrease carbon emissions," said SoCalGas Vice President of Gas Engineering and System Integrity Amy Kitson. "Hydrogen blending is already being used here in the U.S. and around the world every day to power people's homes and businesses, which has shown us that mixing up to 5% hydrogen can be done safely in medium pressure natural gas systems."

"Blending up to 5% hydrogen is a practical, forward-looking step toward decarbonizing our natural gas system," said Sen. Bob Archuleta (D-Pico Rivera). "It leverages existing infrastructure to reduce emissions today while planning for a cleaner energy future."

"We should not delay this important step toward making our entire energy system more sustainable and clean," said Jack Brouwer, UCI professor of mechanical and aerospace engineering and director of the UCI-based National Fuel Cell Research Center. "All objective analyses of the energy transition show that use of both the gas and electric systems are required to achieve sustainability, reliability, and lowest cost goals.  Beginning to evaluate the sustainable transformation of the gas system with clean hydrogen blending is important to meet sustainability and cost goals."

Hydrogen blending is the practice of mixing hydrogen with natural gas, which the State of California has said could help decarbonize its energy grid. In response to the CPUC's 2022 decision, the state's investor-owned utilities have proposed five hydrogen blending demonstration projects as the state considers a systemwide hydrogen blending standard. SoCalGas currently has proposed two of these hydrogen blending demonstration projects, one of which is designed to blend up to 5% hydrogen and thus would not be completed if the CPUC approves the pending petition for modification.

Research, real-world projects demonstrate hydrogen blending effectiveness. Advancements over the past four years, supported by research and real‑world demonstrations in the U.S. and other countries, show that low-level hydrogen blends do not harm pipelines and appliances, or impact system safety, enabling the use of existing infrastructure without modification. States like Utah, which have already completed similar demonstration projects, have shown that blending up to 5% hydrogen with natural gas can be done safely and doesn't require any changes to customers' appliances. In addition, Hawai'i Gas has safely been using up to 15% hydrogen in its fuel mix with regular, everyday appliances for more than a half-century, allowing a less carbon intensive fuel mix to power homes and businesses.

Several studies have also shown that blends of up to 20% hydrogen can safely power regular everyday household and business appliances, while reducing carbon emissions and potentially even reducing nitrous oxide (NOx) emissions.

SoCalGas has been successfully demonstrating the use of hydrogen blending for more than a decade, having completed the first-ever power-to-gas hydrogen blending project in the United States in 2016 at UC Irvine to help power the campus. Since then, the company has also completed a number of demonstration projects, including the development and operation of the [H2] Innovation Experience, North America's first-ever clean renewable hydrogen powered microgrid and home which uses hydrogen blends up to 20% to power its off-the-shelf appliances.