Southern California Gas Co. (SoCalGas) says new research on power-to-gas technology shows the technique holds the ability to dramatically increase the use of intermittent renewable energy. The finding came out of ongoing research conducted at the University of California, Irvine (UCI) and funded by SoCalGas.
Preliminary research findings, recently announced at UCI’s International Colloquium on Environmentally Preferred Advanced Generation (ICEPAG), demonstrated that the campus microgrid could increase the portion of renewable energy it uses from 3.5% to 35% by implementing a power-to-gas strategy.
“This research clearly shows that power-to-gas technology can increase the use of renewable energy and should be an important component in meeting California’s clean energy and greenhouse-gas reduction goals,” says Jeff Reed, director of business strategy and advanced technology at SoCalGas.
“The ability to increase the mix of renewables on campus by tenfold is truly significant,” says Jack Brouwer, associate professor of mechanical and aerospace engineering and civil and environmental engineering at UCI and associate director of the Advanced Power & Energy Program (APEP). “With power-to-gas technology, you don’t need to stop renewable power generation when demand is low. Instead, the excess electricity can be used to make hydrogen that can be integrated into existing natural gas pipeline infrastructure and stored for later use. The Southern California Gas Co. system alone is made up of over 100,000 miles of pipeline. This study suggests that we could leverage that installed infrastructure for storage and significantly increase the amount of renewable power generation deployed in California.”
According to SoCalGas, power-to-gas technology takes excess renewable electricity that would otherwise go to waste and converts it to hydrogen, which can then be blended with natural gas and utilized in everything from home appliances to power plants. The utility says a 5% blend of hydrogen in SoCalGas’ natural gas system would provide storage capacity equivalent to $130 billion worth of battery systems if purchased at the U.S. Department of Energy future cost of $200/kWh. Renewable hydrogen can also be used in hydrogen fuel cell vehicles or converted to methane for use in a natural gas pipeline and storage system.
The conversion of renewable electricity to hydrogen enables long-term storage of large amounts of carbon-free power, and SoCalGas says scientists note this is a significant advantage over lithium-ion batteries, which store energy for shorter time periods and will require extensive construction of battery systems and infrastructure.
The new finding comes from a pilot project begun with funding from SoCalGas and the participation of Proton OnSite, which manufactured the electrolyzer that produces hydrogen from electricity and water. UCI engineers and graduate students have been working to determine how beneficial the technology might be and its feasibility for statewide or regional power grids. SoCalGas notes power-to-gas systems are currently in place in Germany and Canada.
The study used data from the UCI campus microgrid, which includes a 4 MW solar installation. Simulations showed that by storing excess solar power on sunny days and using an electrolyzer to produce renewable hydrogen, the microgrid could support an additional 30 MW of solar panels. The increased solar deployment raised the fraction of renewable power used on campus from 3.5% to 35%, according to SoCalGas.