SACRAMENTO, Calif. — Robert A. Karmann, 53, of Clayton, pleaded guilty today to his participation in a massive fraud scheme involving a solar energy company in Benicia that defrauded investors of approximately $1 billion, U.S. Attorney McGregor W. Scott announced.

Those losses resulted from investment transactions in solar energy hardware valued at approximately $2.5 billion. Karmann is the third person to plead guilty to federal criminal charges relating to the fraud scheme since October.

According to court documents, between 2011 and 2018, the solar energy company manufactured mobile solar generator units (MSG), solar generators that were mounted on trailers. The company touted the versatility and environmental sustainability of the MSGs and claimed that they were used by cellphone companies to provide emergency power to cell towers in the case of a power failure. They were also claimed to be used to power lights at sporting and other events.

The company solicited investors by claiming that there were very favorable federal tax benefits associated with investments in alternative energy. The company structured the transactions in order to maximize the tax benefits to the investors. Investors would buy the MSGs without ever taking possession of them. They would pay a percentage of the sales price and finance the balance with the company. Then the investors would lease the MSGs back to the company, which in turn leased them to third parties. A portion of the lease revenue would be used to pay the investors’ debts to the company and to the investors. The third‑party leases, however, generated little income and the company paid early investors with funds contributed by later investors.

According to court documents, Karmann, a certified public accountant, joined the company in 2014 and became its Chief Financial Officer (CFO). Karmann and his co-conspirators used fraudulent financial statements and other false information to hide from investors the company’s use of later investor payments to pay financial obligations the company made to earlier investors—in a classic Ponzi scheme. In his role as CFO, Karmann managed and directed the periodic transfers of new investor money to pay the company’s obligations to existing investors. Karmann also disseminated false financial and other information to investors to mislead them about material aspects of the MSG investments. Karmann’s criminal conduct was intended to create the false impression for investors that the MSG investments were operating as promised, which helped lull existing investors, lured prospective investors, and caused investors to seek more than $1 billion in tax benefits from the Internal Revenue Service to which they were not entitled. Karmann also pleaded guilty to securities violations associated with the same investment fraud scheme.

On Oct. 22, Joseph W. Bayliss, 44, of Martinez, and Ronald J. Roach, of Walnut Creek, each pleaded guilty to related charges. The investigation into the fraud is ongoing.

This case is the product of an investigation by the Federal Bureau of Investigation, IRS‑Criminal Investigation, and the Federal Deposit Insurance Corporation Office of Inspector General. Assistant U.S. Attorneys André M. Espinosa and Kevin C. Khasigian are prosecuting the case.

Karmann is scheduled to be sentenced by U.S. District Judge John A. Mendez on March 31, 2020. Karmann faces a maximum statutory penalty of 15 years in prison. The actual sentence, however, will be determined at the discretion of the court after consideration of any applicable statutory factors and the Federal Sentencing Guidelines, which take into account a number of variables.