Results of the approximately $18 million study were filed by the utility in mid-summer with the Indiana Utility Regulatory Commission. The utility, a subsidiary of Charlotte, North Carolina-based Duke Energy Corp., is seeking IURC approval for a second, $42 million study to gauge the estimated cost of storing the CO2 at a yet-undermined location.

Edwardsport’s critics greeted the CO2 capture study with disappointment, predicting the high capital costs would preclude the company from going forward with installing CCS technology on the baseload plant.

Duke Energy Indiana spokeswoman Angeline Protogere said a final decision has not been made on whether to add the CCS technology to Edwardsport, the largest IGCC plant ever built in the U.S. “We have always said this plant makes sense whether we pursue carbon capture or not,” she said. “The plant is well-positioned to comply with a host of new regulations that have been proposed. It will be one of the cleanest coal plants in the nation and a model for technology we believe will keep coal in the mix for years to come.”

Currently, the project’s recoverable cost is set at $2.35 billion by the IURC. Duke is requesting an increase to $2.88 billion while critics, including several environmental and industrial groups, want the allowable costs rolled back to $1.985 billion, the original amount approved by the commission in late 2007.

Edwardsport is scheduled to begin service in late 2012.