Attention Tri Cities Tennessee Valley Authority customers – your light bills will still be going up, but not as much as originally announced. TVA will be trimming electric rates by about 6 percent on Jan. 1 to account for lower fuel costs. The savings should be about $4 to $8 a month to the 8.8 million residential consumers receiving TVA electricity in Tennessee, Kentucky, Alabama, Mississippi, Georgia, North Carolina and Virginia. The change reflects a 25 percent reduction in the federal utility’s fuel cost charge, which is adjusted quarterly. The reduction will help offset a 20 percent rate hike TVA put into effect with the start of its fiscal year Oct. 1. It was the federal utility’s highest rate increase in three decades and blamed largely on rising fuel costs for its power plants and power purchased from others.