Horizon attracted customers by offering a rate that was lower than Delmarva Power, but PSC officials say when contracts expired last year, customers were renewed at significantly higher rates - as much as 80 percent more.
The company, which at one time more than 7,000 customers in Delaware, will pay $100,000 into the settlement fund, and it principals will pay the rest.
Horizon must suspend operations in Delaware within 60 days. Its remaining customers will be switched over to Delaware Power, unless they opt to switch to a different provider.