Manure from pig farms, sludge from brewing beer and leftover food scraps from millions of homes and restaurants across the country could soon have more important purpose than ending up in landfill. According to advocates of renewable natural gas (RNG), the United States could produce enough energy from these waste products to power 3 million homes.
New large-scale projects funded by utilities and third parties are springing up across the country, extracting methane gas from waste produced by hog farms, dairy farms, sewage treatment plants and landfills. Using anaerobic digesters, which are much larger than similar technology that has been used on a smaller scale, investors like Vanguard Renewables hope to soon emerge as important energy providers.
Vanguard is currently constructing an RNG facility on a farm in Vermont, which will supply RNG through a pipeline to local businesses and schools. “Producing RNG for pipeline injection and vehicle fueling is the evolution of where everything is going in the biogas sector,” argues John Hanselman, CEO of Vanguard.
The estimate that biogas could power 3 million homes derives from a 2014 study produced jointly by the Environmental Protection Agency, Department of Agriculture, and Department of Energy. The researchers assume that the US could support 13,000 RNG sites, which would produce a total of 654,000 cubic feet of biogas per year. While these figures may seem a long way off, some state governments and third-party investors are taking steps to help the industry reach these goals.