A dairy making sure manure isn’t wasted
December 17, 2012 by Dan Stone National Geographic Magazine
December 17, 2012 – It takes a lot of energy to produce milk. Albert Straus would know. He owns and runs the Straus Family Dairy and a nearby creamery in Tomales Bay, just north of San Francisco, CA.
Every day, each of his 300 cows produce 120 pounds of manure. Considering that dung contains lots of methane, Straus decided several years ago that he’d tap the waste for its full potential. He built a methane digester on his farm. When he showed it to us, the digester looked simply like a bubbling pond enclosed by a large tarp. But the gas inside serves up 960 kilowatt hours of electricity each day, enough to power Straus’s entire dairy. And his electric car. READ MORE
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