Your power bill may be lower than usual this month largely due to heavy rains in May.

The Tennessee Valley Authority recalculates its wholesale rates at the beginning of every month based on fuel and purchased power costs. This July's rate is about 10 percent lower than last year.

The Knoxville-based utility says the unusually wet weather caused hydroelectric power generation to stand at 138 percent of normal levels through the first half of the year. That means TVA didn't have to buy as much other fuel to meet increased demand during the summer months.

TVA is the nation's largest public utility. It provides power to about 9 million people in Alabama, Georgia, Kentucky, Mississippi, North Carolina, Tennessee and Virginia.

Tags: Tennessee Valley Authority, power rates, hydroelectric power, Heavy Rains