Lower electricity rates are on the way for customers of the state’s largest electric utility company. The Public Service Commission has voted five to nothing to approve an agreement between the state and AmerenUE over allegations the company overcharged its customers. Under the deal, customers will share in a one-time $40-Million credit and will benefit from rate decreases totaling about 5.4 percent over the next three-and-a-half years. P.S.C. Chairman Kelvin Simmons says the deal is a good one for all concerned, adding customers should see the credit and the first of the rate decreases by the next billing cycle.