Minnesota Attorney General Keith Ellison announced a lawsuit Tuesday against four Utah-based companies, alleging they violated consumer protection laws and used deceitful business practices to push Minnesotans into expensive solar panel contracts without delivering on promised bonuses or tax incentives.

The lawsuit against Brio Energy and connected companies, their executives and some lenders they worked with follows complaints from dozens of homeowners who said the salespeople used high-pressure tactics to get them to sign contracts.

"These Minnesotans were trying to do the right thing for their families and our state and our environment, and instead they were scammed by unscrupulous companies using deceptive tactics to defraud," Ellison said at a news conference Tuesday.

His office estimates more than 400 Minnesotans were targeted by the companies, with contracts totaling millions of dollars. The individual contracts ranged from $20,000 to $55,000 for solar panels.

The lawsuit alleges the companies' sales force targeted people through Facebook ads or door-to-door pitches, suggesting they were connected to utility companies and often wearing utility vests to look official.

They told some homeowners they were signing documents to get a quote on panels costs and energy savings, but instead they were signing an installation contract.

By the time most homeowners realized what they signed, a three-day cancellation window on the contract had expired. The lawsuit alleges the companies threatened homeowners with legal action and thousands of dollars of termination fees when they tried to cancel their contracts.

The companies would then take weeks or months to actually install the panels and avoided promises to give customers a $1,000 sign-up bonus, according to the Attorney General's Office. The salespeople used misleading information about tax rebates, energy bill prices and savings estimates that never materialized, consumers said.

"I'll be spending thousands of dollars more than I expected to on the life of the loan and there will never be a bill with negative usage," said Matt Malinosky, who had panels installed on his home in Prior Lake and was promised the upfront costs would be rewarded with tax rebates and low electric bills.

Barbara Whiteis of Monticello said she struggled for months to get her panels installed and even longer for them to start operating and seeing the benefits in her electric bill.

"I'm paying double payments, still am, even though my system was hooked up," said Whiteis.

The lawsuit filed in Hennepin County District Court names companies Brio Energy LLC, Bello Solar Energy, Avolta Power Inc. and Sunny Solar Utah LLC as defendants, along with company executives and lenders who partnered with the solar companies to finance Minnesotans' purchases. Calls to the companies were not immediately returned.

The lawsuit is seeking civil penalties against the companies and restitution for consumers, and asks the court to order that current and future customers be able to cancel their installation contracts and loans in "a reasonable period of time."

Ellison said he hopes this doesn't dissuade Minnesotans from considering solar energy options for their home, but he warned consumers to watch out for salespeople who show up at their door unannounced using high-pressure tactics.

"I encourage Minnesotans who think it might be right for them to do their research and ask lots of questions," he said. "Holding bad actors like these accountable helps every legitimate solar-panel company and every homeowner that wants to save money, improve their home, and do right by the environment."