KNOXVILLE, Tenn. (AP) - The Tennessee Valley Authority has approved a huge electric rate increase for millions of consumers across the seven-state region.

TVA directors meeting in Knoxville Wednesday approved a total increase in rates of 20 percent effective Oct. 1.

The impact on the average TVA household will be an increase of $12 to $15 a month per 1,000 kilowatt hours used.

The average TVA household uses 1,320 kilowatt hours per month. The increase is broken down as 17 percent in a quarterly fuel adjustment charge to offset rising costs in coal and natural gas prices.

The other 3 percent is part of the base rate increase taking effect under the new $12.6 billion budget for fiscal 2009.

This would be the largest increase at TVA since a 20.2 percent increase in 1974.