The NCUC approved certificates of public convenience and necessity for up to five combustion-turbine units at each site, a total of 10 units. The DENR issued air permits for up to seven units at Richmond County and up to five units at the Rowan County site.
Work is already under way at both sites.
Each of those units, as built, will be operated primarily for peaking generation used mostly on the hottest and coldest days of the year to provide electricity during periods of high customer demand. The combined-cycle technology entails the installation of equipment to recover the exhaust heat generated by normal combustion turbine operation. The exhaust heat is then turned into steam and used to power a steam turbine generator to more efficiently manufacture additional electricity. Combined-cycle plants are more efficient than peaking units. Given the efficiency improvement, a combined-cycle facility might be operated approximately 60 percent of the time, whereas a peaking unit is used about 10 percent of the time.