The cost to build a coal gasification power plant near Edwardsport, Indiana, is going up.
Duke Energy says it will have to add at least $150-million to the project's price tag, that represents about a six percent increase.
Duke officials also hint more increases may be coming.
The company says it was difficult to estimate the original cost because this is the first time such technology has been used on a project this large.
Duke originally estimated a 17 percent rate hike for customers to cover the cost of the new facility.