HispanicBusiness

AT&T became Bloom Energy's largest corporate customer Tuesday when it announced plans to more than double its existing contract with the Sunnyvale-based fuel cell startup.

Last year, AT&T signed an initial contract with Bloom for 7.5 megawatts. On Tuesday, the telecommunications giant added an additional 9.6 megawatts.

Bloom Energy's fuel cells will power 28 AT&T facilities in California and Connecticut, including two facilities in San Jose. AT&T is not buying Bloom's technology outright; it is buying the electricity Bloom produces through long-term contracts known as power purchase agreements. The cost of the PPA's was not disclosed.

The total size of the agreement, for 17.1 megawatts, makes AT&T Bloom's largest nonutility fuel cell customer.

"We have high-tech centers that run around the clock, and the Bloom Boxes have worked perfectly," John Schinter, AT&T's director of energy, said in an interview. "We haven't had any outages, and this allows us to have on-site generation with high reliability."

Fuel cells use hydrogen, natural gas, methane or other fuels to generate electricity through an electrochemical process that produces fewer emissions than a typical coal-fired power plant. Unlike wind turbines or solar panels, fuel cells operate 24 hours a day, providing what's known as "baseload" power. That's made them increasingly attractive to companies with intense data center needs, like