SACRAMENTO, Calif. (AP) — An attorney for a California solar power company has been sentenced to 11 years and five months in prison for helping orchestrate a $1 billion fraud scheme, federal prosecutors said.

Ari Lauer, 61, pleaded guilty in October to 23 felony counts including bank fraud and wire fraud, the U.S. Attorney’s Office said in a statement. He was sentenced on Monday.

Lauer was outside counsel for DC Solar, based in Benicia in the San Francisco Bay Area. Between 2011 and 2018, the company marketed mobile solar generator units. The firm touted the trailer-mounted units as being able to provide emergency power for cellphone companies or lighting at sporting and other events.

But executives started telling investors they could benefit from federal tax credits by buying the generators and leasing them back to DC Solar, which would then provide them to other companies for their use, prosecutors said.

In reality, DC Solar sold more generators than it made, used phony financial statements and lease contracts to conceal the fraud and in a classic Ponzi scheme repaid early investors with money from later ones, prosecutors said.

About 9,000 of the approximately 17,000 generators that DC Solar claimed to have made didn’t exist, according to prosecutors.

“Without the participation of Lauer, the DC Solar fraud scheme would never have been operational,” U.S. Attorney Eric Grant said in a statement Monday.

Among those suckered by the business were Warren Buffett’s Berkshire Hathaway Inc.

DC Solar founder Jeff Carpoff was sentenced in 2021 to 30 years in prison and ordered to pay $790.6 million in restitution for conspiracy to commit wire fraud and money laundering.

Since then, five other people, including Carpoff’s wife, Paulette Carpoff, were sentenced to prison in connection with the fraud.