By Beth Gardiner, The New York Times.
LONDON — In villages across China, tens of millions of families use farm and household waste to make clean cooking fuel in backyard fermenters. Germany generates as much electricity as two nuclear power plants with the gas produced by decaying plant matter and animal slurry. Near San Francisco, a landfill extracts enough energy from its stewing garbage to power 300 trucks on their daily runs.
Around the world, both household-run operations and industrial-scale facilities are using centuries-old technology to extract a fuel known as biogas from crop waste, manure, kitchen scraps and even sewage.
Proponents cite the multiple benefits of harnessing biogas, such as reducing emissions of the powerful climate-warming gas methane, cutting waste streams and saving the lungs of those in poor countries who would otherwise burn wood or other smoky fuels indoors. After biogas is extracted from organic material, a rich fertilizer remains.
There is talk in the United States of creating a network of natural gas filling stations for trucks, infrastructure that could easily be used for biogas as well. “If the fracking boom can pay for that,” said Heather Youngs, a senior fellow at the Berkeley Energy and Climate Institute, “biogas can inherit that and green it.”