SUNNYVALE -- Breaking silence in a controversy over its failure to meet federal wage requirements for 14 Mexican workers, clean-tech startup Bloom Energy on Thursday blamed the episode on "a breakdown in our internal processes" and called it "inconsistent with our culture and values."

Bloom, which has won national acclaim for its innovative fuel-cell technology, said it cooperated with a U.S. Department of Labor investigation that found the company brought the Mexican workers to its Sunnyvale plant and paid them the equivalent of $2.66 an hour in pesos, wired to accounts in Mexico, while they worked alongside U.S. employees.

Without offering a detailed explanation of what happened, the company said it's taking

steps "to ensure that this does not occur again." Federal officials said the men worked in Sunnyvale for different periods, up to several weeks at a time over the last two years, while being paid less than a third of the federally required minimum wage.

Bloom was required to pay $70,000 in back wages, damages and fines in the case, under a court order signed last week by U.S. District Judge Lucy Koh. The order also bars Bloom from violating federal wage and overtime rules in the future.

In a brief statement, the company said: "Bloom Energy cooperated and participated fully with the Department of Labor's investigation during which it was found that 14 workers in our Sunnyvale plant were not paid properly. This is inconsistent with

our culture and values. It was the result of a breakdown in our internal processes."

The statement added: "We take full responsibility for this and have paid back wages, damages and fines ... Furthermore, we are correcting and strengthening our internal processes to ensure that this does not occur again."

Bloom's statement didn't address the workers' immigration status, although a Labor Department spokesman said the 14 workers came to the United States on visitors' visas, which generally don't allow holders to work while they are here. The department has no jurisdiction on visa issues, and U.S. immigration officials said they couldn't comment on the case.

A spokeswoman for a Silicon Valley immigrant-rights group said she was pleased the government had interceded on the Mexican workers' behalf.

"It can be very difficult for workers to fight for their rights or for basic labor standards that are supposed to be provided regardless of their immigration status," said Jazmin Segura, a policy advocate with the Services, Immigrant Rights and Education Network, or SIREN. "A lot of times, immigrant workers are too afraid to confront their employers."

A former Bloom contractor said the Mexicans had worked for Bloom

in their own country and were brought here for training before being put to work at the Sunnyvale plant. Federal officials said the men, who have since returned home, were hired with the help of Intermex, a Mexican company that leases facilities, hires personnel and obtains permits for U.S. companies that want to operate in Mexico.

Bloom's CEO and principal founder, K.R. Sridhar, is an Indian immigrant who taught aerospace engineering at the University of Arizona and advised NASA on Mars exploration before moving into the green technology field.

Contact Brandon Bailey at 408-920-5022; follow him at Twitter.com/BrandonBailey