New sources of renewable natural gas (RNG) and gas-to-power storage concepts are getting a boost under a $1.3 million research effort supported by the U.S. Department of Energy (DOE), Southern California Gas Co. (SoCalGas) and national and university research organizations.
The ambitious research seeks to deploy microbes to convert carbon dioxide (CO2) directly to methane using renewable electricity under a process the scientists have dubbed microbial elecromethanogenesis, or ME. An end-goal is to produce more and less expensive volumes of renewable electricity and RNG, a market that is expanding beyond the transportation sector.
"ME could become a highly efficient, large-scale storage technology for excess wind and solar energy," said a SoCalGas spokesperson.
Research at California-based Lawrence Livermore National Laboratory (LLNL) and Stanford University’s School of Engineering's Spormann Laboratory are in line to split up to $800,000 in grants, with co-funding of up to $400,000 from Sempra Energy’s SoCalGas utility.
"Through this project we intend to devise scalable, efficient prototype reactors that enable both economical upgrading of biogas and storage of renewable electricity as methane," said LLNL chemist Sara Baker. She noted that plans are to fabricate reactors tailored to the requirements of microbes and the overall process.
Between 3,300 and 7,800 GWh of excess solar and wind energy could be curtailed in California by 2025, according to a recent study by the Lawrence Berkeley National Laboratory. "If that excess energy were converted to methane and stored as RNG, it would provide enough renewable energy to heat up to 370,000 homes," a SoCalGas spokesperson said.
"This technology has the potential to cut the cost of processing biogas while nearly doubling the amount of this easily stored renewable energy and reducing carbon dioxide emissions," said SoCalGas’ Yuri Freedman, senior director for business development. "It could make a big difference for small-scale biogas producers."
SoCalGas is funding the research to help develop power-to-gas, or P2G, technologies, to salvage and use excess volumes of renewable energy.
Meanwhile on the national level, alternative fuel advocates in the transportation sector are keeping an eye on Congress and the Trump administration for actions that could impact future developments. In July, the Light-Duty Natural Gas Vehicle (NGV) Parity Act of 2018 was introduced by Sen. Bill Johnson (R-OH) as a companion bill to one by Sen. James Inhofe (R-OK).
Johnson's bill seeks to require federal agencies to treat all alternative fuel transportation options the same, applying the same regulatory treatment to NGVs as to electric vehicles.
Johnson said federal policies "must encourage an all-of-the-above approach" to energy production and consumption. "As the world's largest producer of natural gas, we must take full advantage of this abundant, job-creating resource.”