Duke Energy filed a report with the Indiana Utility Regulatory Commission updating the agency on the expected cost of completing a clean coal gasification power plant currently under construction in southwest Indiana. The company upped the cost estimate of the plant by $365 million to $2.35 billion. This translates into a 2% rate impact for customers between 2008 and 2013. Duke president James Turner said the increase was similar to increases for other types of buildings. The plant is located in Edwardsport, Ind. and is expected to be completed in 2012. The 630-megawatt plant will use integrated gasification combined cycle technology. That total cost will be offset by about $460 million in local, state, and federal tax incentives.