Duke to invest 100 million in solar

That will include a $100 million investment in rooftop solar energy, a program that will involve working with commercial and even residential customers.

Duke has been considering its options on owning alternative energy capacity or buying it. Chief Executive Jim Rogers says the corporation has decided its utilities will do both.

"As a utility company, we build, operate and dispatch solar power," he says.

Rogers provided no timetable on when Duke would start building its own renewable-energy plants. North Carolina will require some renewable energy from utilities starting in 2012. The state's utilities are to provide 12.5% of the energy they sell in North Carolina from renewables or conservation by 2021.

But Duke will ask the N.C. Utilities Commission this summer for permission to invest the money in rooftop solar. Rogers has talked generally about this plan before. It will involve dipatching excess power generated by customer's solar panels as if it were power from another Duke plant.

Rogers says some of Duke's utilities will also own their own wind capacity. But he says wind energy is a less likely alternative in the Carolinas.

Duke may negotiate the purchase of wind energy here. But the only place wind farms would work in Duke's footprint is along the ridge lines in the western mountains and along the coast. "I'm not sure many environmentalists would salute that proposal," Rogers says.

A privately developed wind farm began selling electricity produced by wind turbines to Duke Energy Indiana in April. Duke also bought Tierra Energy last year, which is developing up to 1,000 megawatts of capacity. That company will build energy for Duke's commercial operation, not its utilities.

Rogers is also talking about Duke owning solar generation outright. "Solar is something that has the potential for its costs to come down over time," he says. "And clearly as it does, we want to blend solar in with our low-cost nuclear and coal here."