SOLAR ECLIPSE
Unraveling the big event's impact on power grids
Ninety minutes before the arrival of the solar eclipse on Aug. 21, a large, thick cloud drifted in to obscure the sun, curdling the hopes of Tom Petray, a retired Texas State University professor who had lugged a vacuum-cleaner-sized telescope to the Tennessee Valley Authority's Melton Hill on the Clinch River outside Knoxville to see the once-in-a-lifetime spectacle.