The case is being heard without a jury by Judge Lacy Thornburg.
Myers said TVA's coal-fired plants produced about 30 percent more electricity last year than plants in North Carolina while emitting about the same amount of sulfur dioxide. But under cross-examination, Myers acknowledged that Duke Energy and Progress Energy are poised to significantly reduce emissions as required by the Clean Smokestacks Act approved by state lawmakers in 2002.
Myers said the TVA pioneered the use of scrubbers to control pollution at one of its plants in 1977. The agency has since spent $4.8 billion on pollution controls. But he acknowledged that improvements in emission levels have largely been driven by federal and state regulations.
The TVA has scrubbers installed on eight of its 59 power generating units at 11 plants, said Ron Nash, who oversees the construction of pollution controls. The installation of scrubbers should be completed on units at three more plants in eastern Tennessee by 2013, he said. But Nash said it would be difficult to comply with all of North Carolina's demands because it takes about five years to design and construct scrubbers.
TVA estimates its witnesses will be on the stand for five to six days.
The lawsuit filed by N.C. Attorney General Roy Cooper seeks to force the TVA to reduce the amount of pollution that drifts into the state from plants in Tennessee, Alabama and Kentucky. North Carolina has already rested its case.