A California utility company plans to test an innovative energy storage technology that converts green electricity into hydrogen gas, potentially solving the problem of storing excess renewable energy created on the grid. The hydrogen gas can be used as an energy source as is or combined with a gas utility’s existing methane. The Southern California Gas Company (SoCalGas), the largest natural gas utility in the United States, will be the first to demonstrate this energy storage system, known as power-to-gas.
Using electricity generated from renewable sources like solar, the technology is carbon free. Electrolyzers break water into its constituent oxygen and hydrogen. The hydrogen can be stored for much longer than energy can be stored in batteries, which are still limited to short-term storage. With power-to-gas, existing natural gas infrastructure can be used to carry the fuel, creating what the project’s participants are calling the world’s largest storage technology.
As we reach high levels of renewable energy on the grid, storing the electricity generated by solar power and other variable energy sources will help unlock greater use of these renewable resources in the US and throughout the world. This project will examine a unique way to reduce the capital cost of energy storage.
The demonstration project is being carried out by SoCalGas in partnership with the National Fuel Cell Research Centre (NFCRC) and the Department of Energy’s National Renewable Energy Laboratory (NREL). A scientist at NREL said that the system promises to be a “unique way to reduce the capital cost of energy storage.”
The company that will provide the electrolyzer technology, Proton OnSite, said that it has launched a new commercial-scale platform for the project, referred to as the M Series. Two electrolyzers, rated for 7kW and 60 kW of input power will generate the hydrogen using power from a local photovoltaic source. The hydrogen will be injected into a simulated natural gas pipeline at NFCRC. Proton said in a statement that its M Series provides thirteen times greater hydrogen production than other commercial electrolyses. The company’s M Series megawatt platform is shown above, producing 200m3 of hydrogen per hour.
The power-to-gas project with SoCalGas will be a feasibility test for the new technology, providing “validation” of the technical and economic feasibility of grid-scale hydrogen energy storage.
Commercial-scale power-to-gas systems are currently being used in Germany.