Over the past few years, energy giants like Shell, BP and Chevron have all announced similar dairy industry partnerships. In California, the country’s top dairy-producing state, officials estimated that over a hundred publicly supported manure digesters were slated to go online by the end of last year. Less than a decade earlier, in comparison, just six such projects were in the works. Nationally, the number of planned and operational RNG production facilities at livestock and agricultural operations jumped by over 36% in 2021 compared to the year prior.
But some watchers of the biogas boom worry that monetizing avoided emissions could backfire. Environmental justice and animal welfare groups are campaigning against subsidies for the industry and raising questions about the challenges posed by digester technology. For one, digesters can and do leak. They also only mitigate about half of the methane problem posed by the dairy industry. While digesters capture emissions from manure, they do nothing to resolve the issue of emissions from cow burps, which, in California, produce roughly the same amount of methane emissions as manure.