May 13 - McClatchy-Tribune Regional News - Christopher D. Kirkpatrick The Charlotte Observer, N.C.

Inside the garage of Duke Energy's chief technology officer, a refrigerator-sized battery-and-computer station processes electricity from rooftop solar panels.

The electricity powers his home directly. But the battery also stores some of it to be tapped later, if needed.

The battery station, with help from the home's new smart meter, also tracks electricity use, appliance-by-appliance, so a homeowner knows how best to save.

David Mohler's Lake Wylie residence, with all its gizmos, is ground zero for an ambitious solar energy experiment the Charlotte utility believes holds the key to meeting power demand more efficiently and cleanly.

"This is a future world," Mohler said as he stood in his driveway looking up at the gleaming panels on his roof. "But we need to figure out how to improve (solar) technology and bring down the costs. Today, it's too expensive."

The company would like to install similar systems in selected homes throughout its Carolinas territory within a decade. With the equipment, the homes and businesses could become mini-power stations, working as an extended network feeding the regional power grid with electricity.

The utility plans to finish outfitting 5,000 south Charlotte homes with smart meters by this summer and already has installed data relay devices on some power lines. The meters are part of an existing program to track and analyze customer power use. Duke said its 4 million customers in five states will have smart meters in five years. They also are key to a future solar network.

Duke plans to ask Carolinas regulators this summer for permission to start building the network. The batteries could come later.

Duke spokesman Tom Williams said Duke hasn't decided yet if customers will be able to volunteer their rooftops.

With the array of new technology, Duke could burn less coal by drawing unused solar power from homes. For example, Duke could draw power while residents are on vacation. It also could grab power stored in the batteries.

Officials estimate the first phase, over the next decade, would cost about $100 million, expenses passed on to customers through higher rates. Duke has suggested it could install the panels and equipment, while retaining ownership. It could then siphon extra power in exchange for breaks on customers' bills or other concessions, Williams said.

Duke and other utilities say they will need solar networks to meet future energy demand more efficiently as they work to curb carbon dioxide emissions from coal-fired plants.

Rogers told shareholders Friday at the company's annual meeting that creating a network was integral.

The idea has been around for 10-15 years, said Steve Kalland, director of the N.C. Solar Center at N.C. State University. But advances in battery-storage technology has made it more practical, he said.

Solar energy's penetration in the Carolinas is almost zero, Kalland said. "I'm cautiously optimistic."

The technology's growing popularity has brought down costs, but price is still a major obstacle to widespread use, he said. The solar panels and installation at Mohler's house cost $24,000. And the battery, manufactured by GridPoint, was $10,000.

Obstacles also include aesthetics. Some homeowner associations have outlawed solar panels as unsightly, Mohler said. "There are some interesting social issues."

A look to the future

Duke has reasons to find new sources of power:

--Congress is mulling future regulation of carbon dioxide emissions, a byproduct of burning coal in power plants and blamed as a cause of global warming. New regulations could add billions in costs for the industry and its customers.

--Duke says it needs three new nuclear reactors to meet future demand. The plants don't emit carbon dioxide, but projected constructions costs for nuclear plants are escalating. The company has submitted an application with the Nuclear Regulatory Commission to build two reactors in Cherokee County, S.C.

--Duke has started to plan two new natural gas plants to meet demand. The plants are easier and cheaper to construct but more expensive to operate because of the higher price of the fuel.

--The price of coal, once reliably cheap, has doubled in the past year.