Reuters: The cost to finish building Southern Co's controversial coal-gasification power plant in Kemper County, Mississippi, may increase by at least $160 million to $4.5 billion or more, or more than double initial cost estimates, the company said in a filing with regulators. Separately, the utility last week filed a petition asking state regulators to hold a "prudency review" to approve all money spent on the Kemper project through the end of March. In April, Southern Co said it needed to spend an additional...