By Andrew Brown CHARLESTON, W.Va. - First Energy customers could soon be paying slightly higher electricity rates in order to save a struggling Marion County coal-fired power plant.On Friday, the Public Service Commission agreed to reopen a case that deals with First Energy's purchase of electricity from American Bituminous Power Partners, the owner of the Grant Town Power Plant.The decision to review the case is the result of a June 5 petition - jointly filed by the two companies - that asked the PSC to consider altering the current contract between the electric utility and power provider.The request to restructure the power purchase agreement, which requires First Energy to buy a set amount of electricity from the plant, comes at time when the Grant Town power station has struggled to pay its bills, including the $150 million of tax-exempt bonds that were funneled through the Marion County Commission to construct the plant in the early 1990s.The plant produces around 637,000 megawatt-hours annually for First Energy, but that electricity output makes up a relatively small portion of First Energy's sales, which includes roughly 15 million megawatt-hours sold to customers every year.However, if the PSC approves the proposed agreement, it could require the roughly 520,000 First Energy customers in West Virginia to help pay an additional $4.6 million annually starting in 2017 and another one-time $8.8 million increase in 2020.Currently, First Energy pays $34.25 per megawatt-hour.