Google’s search for carbon offsets to cancel out the company’s own impacts has found a Duke University and Duke Energy-backed methane-recovery project on a hog farm.

The pilot project captures greenhouse gases from hog waste and burns them to run a turbine. The system produces enough electricity to power 35 homes for a year, Duke University said in announcing the Google support. It is expected to be able to prevent the release of greenhouse gases equivalent to nearly 5,000 metric tons of CO2 per year, which is like taking 900 cars off the road.

“It is exciting to see the system up and running, and even more exciting that it’s getting recognized by Google,” said Tatjana Vujic, director of the university’s Duke Carbon Offsets Initiative. “Completing this full-scale system and getting it operational is a great testament to its design and the foresight of all of its various supporters.”

The prototype system cost $1.16 million to build at Loyd Ray Farms, a 9,000-head hog finishing operation northwest of Yadkinville, Vujic said. State and federal grants helped begin the project, she added.

How much Google will pay was not disclosed, but Vujic said the school and the Internet giant have a five-year arrangement and that Google’s carbon-offset purchases will go to offset Duke University’s construction and operation-and-management costs.

The university said that capturing the methane creates carbon offset credits for the school and Google, and using it to generate electricity creates renewable energy credits for Duke Energy. Loyd Ray Farms will use surplus electricity on-site.

Vujic said the methane emissions will be documented with a clearinghouse to establish how many tons of carbon Google can claim to have eliminated by buying the credits.

Duke University engineering professor Marc Deshusses and his students are  studying the system’s performance. “Now that the system is on the ground, we have an opportunity to evaluate and quantify all of its benefits and to work on making it more efficient and economical to build and operate,” Deshusses said. “Innovative systems that can reduce greenhouse gases plus take waste and turn it into energy are the kinds of things Duke University is anxious to evaluate and promote.”

It is rewarding to see three years of hard work come into operation and exciting to have Google as a new partner in this project,” said Owen Smith, managing director of Duke Energy’s regulated renewables business. “As North Carolina continues to explore new ways to generate renewable energy from hog waste, this site serves as a showcase for what others can do to capture the energy from hog waste and turn it into usable electricity for customers.”

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