via.wnep.com
Saving Energy to Keep Us Cool While Temperatures Get Hot
AUDUBON, MONTGOMERY COUNTY -- It may not look like much from the outside, but PJM Interconnection outside Philadelphia helps keep your lights on and keep you cool. PJM Interconnection serves 65 million homes and businesses and is the nation's largest electric grid. The place monitors power usage in Washington D.C. and 13 states, including Pennsylvania.