RALEIGH - Duke Energy chief executive Jim Rogers urged state regulators Friday to move quickly and approve the state's biggest power plant project in two decades.

Rogers warned the state Utilities Commission that if the Charlotte utility does not lock in on the $3 billion estimated cost of the power plant, the price will continue to swell. The cost of the plant, slated to be built west of Charlotte, would be paid by customers through rate increases.

With momentum building statewide for alternative energy, the debate represents the biggest opportunity in a quarter-century for critics to force electric utilities in North Carolina to develop alternatives to building nuclear and coal-fired plants.

The state has received about 600 letters from the public, and heard from hundreds of citizens during public hearings, in opposition to the proposed coal-fired plant. Duke Energy has the backing of the Public Staff, the consumer protection arm of the utilities commission, but is opposed by a coalition of environmental groups and by the state attorney general.

"It's the most difficult case I've ever dealt with," said Robert Gruber, director of the Public Staff for nearly 24 years. "This is one time I have absolutely no sense of the outcome. The commissioners are struggling with this one."

The estimated cost of the Cliffside power plant has soared from $2 billion to $3 billion in recent months. The company conceded this week that financing costs will add several hundred million dollars to the project costs.

Rogers said that the future of America's electricity needs will be linked to coal. Not only does coal provide 50 percent of the country's electricity needs now, Rogers said on the third day of hearings in Raleigh, but the renaissance in nuclear power will likely stall amid public opposition and unrealistically low cost estimates.

Duke and Raleigh-based Progress Energy are among a dozen utilities seeking to license new nuclear reactors. But new nuclear plants are looking uncertain, Rogers said, and coal is a readily available domestic fuel source that assures this nation's energy independence.

Duke has $125 million in federal tax credits riding on the approval of the coal-powered units.

"We need [coal-fired power] to drive this economy," Rogers said. "We're not going to shut it down -- we're not going to shut off 50 percent of the lights of this country."

Duke Energy is asking for a ruling by Feb. 28. Timing is crucial if the company hopes to win an exemption from a tax on carbon emissions that is almost certain to be imposed on new coal-fired plants, Rogers said. Such a tax would be an attempt to pay for the environmental costs of carbon dioxide emissions that contribute to global warming.

Commissioner Jim Kerr said that the state faces a difficult choice fraught with unknown risks: natural gas availability, the reliability of renewables, environmental damage from coal, and the uncertainty of nuclear plant costs and storage of radioactive nuclear waste. "To some extent, we're being asked to choose our poison -- which risk we want to accept."

The commissioners repeatedly asked why the company, for all its talk of efficiency and conservation, had made so little headway in alternative energy programs that are being adopted in other states. The programs either require utilities to derive a portion of their electricity from renewables or offer low-interest loans or rebates to customers who buy energy-efficient appliances and take other conservation measures.

Duke officials acknowledged that the company spends virtually nothing on programs that cut energy use.

"This is a crossroads for this state," Rogers said. "We have huge demands in front of us."

Get $150+ in coupons in every Sunday N&O. Click here for convenient home delivery.