The Florida Public Service Commission today unanimously approved Progress Energy's proposal for two new nuclear reactors on an undeveloped site in Levy County.

The new complex is planned for Florida's west coast about seven miles inland from the Gulf of Mexico and eight miles north of the company's Crystal River plant, where Progress operates another nuclear reactor along with four coal-fired plants. The new reactors are projected to come online in 2016 and 2017 and generate enough energy to power about 1.3 million average residential homes.

But they come at a considerable cost to rate-payers.

The reactors' construction is expected to cost more than $17 billion and cause an almost immediate jump in consumer rates of about $7.53 per month. The burden on consumers will continue to grow through 2016, according to data drawn from a recent PSC staff memo and turned into this handy chart by the folks at the Southern Alliance for Clean Energy, who had tried to block the reactor's licensing:

So why will Progress Energy's customers be paying more before the reactors are up and running (assuming they eventually will be)? Because in 2006, the Florida legislature passed a measure allowing power providers to recoup expenses up front as an incentive to build new nuclear plants. Progress is the first company to take advantage of the deal.