Amid historically low natural gas prices and the warmest March ever recorded in much of the United States, coal's share of total net generation dropped to 34% -- the lowest level since at least January 1973 (the earliest date for which EIA has monthly statistics).

Despite seasonally low loads, natural gas-fired generation grew markedly and accounted for 30% of overall net generation by March 2012. Total electricity demand fell this winter as warmer weather reduced home heating requirements.