The commission said that a motion filed by the North Carolina Waste Awareness and Reduction Network (WARN), a nonprofit group pressing for clean power generation, did not make sufficient arguments to revoke the certificate allowing Duke Energy to build the 800MW unit at its Cliffside Steam Station near Charlotte.

Work on the power plant began in January 2008 and it is expected to be completed in 2012. Duke Energy said that the plant is about half finished. It has spent about $1 billion on the plant so far. The plant is expected to cost approximately $1.8 billion.

The facility is said to generate more than double the electricity available for customers than the current units, with lower emissions. The new unit is being built to accommodate the installation and operation of future carbon control technologies.