Coal fired MHD repowering is considered for the TVA Allen Steam Plant. The performance of the repowered plant is presented. Cost comparisons are made of the cost of repowering with MHD versus the cost of meeting similar standards by installing scrubbers and selective catalytic NOx reduction (SCNR). For repowering of a single 250 MWe unit, the costs favor scrubbing and SCNR. If one considers a single repowering of all three 250 MWe units by a single MHD topping cycle and boiler, MHD repowering is more economical. Environmental emissions from the repowered plant are estimated.