The plan was a “win-win-win” for consumers, the environment and the economy, Duke executive president Lloyd Yates said.

“With the availability and near record low cost of natural gas, this comprehensive project will transform the energy system in the region to meet the growing needs of our customers and significantly reduce emissions and water use,” he said.

“We're eager to move ahead quickly on these projects and complete the key components of the plan by the end of 2019.”

The plan's major components include retiring the 376-megawatt Asheville coal power plant, investing about $US750 million to build a 650-megawatt natural gas-fired power plant, and installing solar generation at the site – one of the first combinations of its kind.

The plan includes investing about $320 million to build a transmission substation near Campobello, South Carolina, and connect it to the Asheville power plant with a new approximately 40-mile, 230-kiloVolt (kV) transmission line.

It also includes upgrading and rebuilding additional electrical infrastructure such as transmission lines and distribution substations.

Electricity demand in Duke Energy Progress’ Asheville service area has doubled over the last four decades. The region currently must import about 400 megawatts of power during peak demand periods to ensure system reliability. The region's power demand is also forecast to grow by about 15 percent over the next decade.

In addition, Duke Energy's Asheville coal plant is one of the company's few “must run” power plants, meaning it must operate to maintain reliability, even when it's not economical.