Researchers at Penn State have built a larger and more efficient microbial electrosynthesis reactor that converts carbon dioxide and renewable electricity into methane. The system uses methanogen microbes to combine hydrogen from electrolysis with CO2, producing methane that can be stored in existing natural gas pipelines. The team's zero-gap electrode design kept internal resistance low even after scaling the reactor tenfold, achieving 6.9 liters of methane per liter of reactor volume per day. This approach addresses a key gap in renewable energy: long-duration seasonal storage. While batteries handle hours or days of storage, converting excess wind and solar power into a storable fuel like methane could help balance grids across seasons. The process also recycles CO2 from industrial sources rather than pulling fossil methane from underground. The study, published in Water Research, shows that microbial electrosynthesis can scale without major efficiency losses. If commercialized, this technology could turn renewable electricity into a dispatchable fuel while reducing net emissions from natural gas systems.
