(Photo by Phil Taylor)

Duke Energy’s coal-fired plant in southern North Carolina. The company is studying whether an addition will capture a maximum of mercury emissions. Construction is planned during the study.

Energy demand clashed with economics Tuesday morning at the North Carolina Public Utilities Commission hearing on the state’s long-term electricity demand, and the environment was caught somewhere in the middle of the debate.

I was able to catch the testimony of Duke Energy’s representative at the hearing, Richard Stevie, who manages the company’s market research and energy demand forecasts. Stevie explained to the commission how factors such as future employment, income, wages, industrial production weather and population changes all contribute to the company’s equation for determining future demand.

It gets pretty complicated, and to be honest I’m probably not qualified to evaluate every in and out of his work.

But the message was clear enough. At issue was Duke’s Integrative Resource Plan, which maps out the company’s 18-year energy forecast, and what it plans to do to meet demand.

Marilyn Lineberger, a spokeswoman for the Charlotte-based company, helped me sort it out in the afternoon, saying the company hopes to maintain a diverse energy portfolio of coal, natural gas, nuclear power and renewables. Further the company wants to roll out robust energy efficiency programs.

“North Carolina is the sixth fastest growing state in the nation,” Lineberger said, citing census data. “We’re adding 50,000 new customers each year, and in order to meet that growing customer population we are pursuing a diverse fuel mix for the future.”

Hence Duke’s work to expand its Cliffside coal facility in western North Carolina, as well as its planned nuclear facility in Cherokee County, in far northern South Carolina.. But Lineberger also pointed to a program the company just launched yesterday, which would allow customers to offset their carbon emissions through a partner group, NC GreenPower in Raleigh. The program gives customers the opportunity to neutralize 500 pounds of their own CO₂ emissions by purchasing $4 offsets each month. NC GreenPower would use that contribution to support programs such as reforestation and methane capture from landfills, both of which mitigate the effects of greenhouse gasses, according to a Duke press release issued Tuesday.

Good, but not good enough, said John Blackburn, a Duke University economics professor who specializes in energy efficiency. Blackburn testified at the morning hearing on behalf of Durham-based NC Waste Awareness and Reduction Network, a local environmental group, but he spoke with me before taking the stand.

“At the moment, nobody anywhere should be building a coal plant, given what we know about the threat of climate change and global warming,” Blackburn said, emphasizing also the danger of an investment that could plague the company down the road if carbon emissions are eventually capped as foreseen by both presidential candidates.

Duke’s CEO Jim Rogers has been a leading proponent among utility leaders for such a program to be implemented. “It affects the viability of the company to spend billions and billions of dollars on plants that are going to last 40 years when the future right now is so fluid that it’s financially very risky,” Blackburn said.

Onward to Gaffney, S.C., the site of what Duke hopes will be its fourth nuclear station. I’ve been turned away from the site grounds by a security guard once already last night, but I’m hopeful Gaffney’s mayor Henry Jolly will give me a tour today.

Stay tuned.