TVA said in a statement Wednesday the increase takes effect in billing periods that begin March 1.
The upward fuel cost adjustment is the first since October 2008.
The adjustment is the way TVA manages changing fuel costs and the cost of purchased power.
TVA began the fiscal year Oct. 1 with an 8 percent general rate increase.
TVA is the nation's largest public utility with nearly 9 million consumers in Tennessee, Alabama, Mississippi, Kentucky, Georgia, North Carolina and Virginia.