MEMPHIS, TN - The Tennessee Valley Authority's reliance on coal has dropped and the use of natural gas as fuel to generate electricity has increased.

According to The Commercial Appeal, TVA's use of gas climbed 70 percent in the fiscal year just ended. At the same time, coal-fired generation declined 30 percent from fiscal 2011. The fiscal years end Sept. 30.

TVA Vice President Bob Dalrymple said the federal utility is trying to achieve a good mix of generation sources, so it can adjust as the market shifts.

The greater use of gas by TVA mirrors a national trend as hydraulic fracturing in drilling releases abundant sources of the fuel.

Nuclear generation also is a major player, accounting for one-third of the power produced by TVA.