As natural gas prices continue to rise, biomethane fuel is becoming cost-competitive with natural gas and diesel, and is much cheaper than hydrogen.
There are 8.5 million cows in the United States, producing enough manure to potentially power about a million cars. California has particularly good reasons for using biomethane.
The technologies for converting dairy manure to biomethane are already used at several landfills around the United States and elsewhere. Sweden has made significant investments in biomethane and is developing the capacity to meet 20% of its vehicle fuel demand with biofuels. Already, Sweden has 17 plants producing biomethane and runs 7,000 cars and buses on it.
Currently, methane digesters are used on some U.S. dairy farms to trap the methane released from cow manure and generate electricity. As a result of Sustainable Conservation's work with California dairy producers, 12 digests are now operating or under construction, which will generate about $1.6 million in electricity — enough to power 2,000 homes. This process will also help divert more than 400,000 tons of manure from 36,000 cows.
These methane digesters can be upgraded to convert dairy manure to biomethane, which can be used in place of natural gas to fuel buses and other vehicles. The future of biomethane depends larger on the willingness of the public and private sectors to invest in advancing the technology, infrastructure and public policy framework that can support large-scale biomethane production, distribution and use.
Sustainable Conservation's partners on the biomethane study, "Biomethane from Dairy Waste," included Western United Dairymen, Institute for Environmental Management, Great Valley Center, CalStart and RCM Digesters. The study was funded by a grant from U.S. Department of Agriculture.