A start-up solar panel maker on the Iron Range has been given more time to repay a $1.5 million state loan.

Silicon Energy, whose Mountain Iron, Minn., plant opened last year, was supposed to begin $40,000 quarterly loan payments in April to the Iron Range Resources and Rehabilitation Board (IRRRB), a state economic development agency.

But the company missed the first two payments, citing slow sales. In response, IRRRB Commissioner Tony Sertich has approved a new payment schedule that gives Silicon Energy until next October to makes its first payment, agency and company officials said Tuesday.

As part of the deal, Silicon Energy will give a 5 percent discount on any municipal solar project in the Iron Range region. Other loan terms, including the 3 percent interest rate, are unchanged. The loan helped the company acquire equipment.

Silicon Energy, whose headquarters are in Marysville, Wash., blamed slower-than-expected first-year sales at the Minnesota plant for its troubles repaying the loan.

But Gary Shaver, president of Silicon Energy, said Tuesday the company's prospects are good. In 2013, the Minnesota plant will begin manufacturing a second-generation solar panel that is lighter, less expensive to install and has up to 8 percent more output, he said.

"There is no lack of interest in our product," he said.

As production expands, Shaver said, the company hopes to reduce panel manufacturing costs through the economies of scale.

David Shaffer • 612-683-7090 @ShafferStrib