Duke Energy last week said that testing was under way in preparation for commercial operation next year of its 630-MW integrated gasification combined cycle (IGCC) Edwardsport power plant in Knox County, Ind.

The plant has “successfully produced electricity using natural gas, and the next phase is testing the coal-gasification equipment,” the utility said in a statement. The first coal-gasification test may occur as early as this week, it said.

When the coal is converted into a synthetic gas, it is sent to the gas turbines, where it is burned to make electricity. However, if the synthetic gas does not meet certain standards, it is diverted to the gas flare tower on the plant property, where it is ignited and burned safely. The gas flare also is used during each startup and shutdown of the plant. “This gas flare will be bright and somewhat loud, and it will be especially noticeable at night. The flare will normally last only as long as it takes to shut down the coal gasification process, usually less than 30 minutes,” the utility warned nearby residents.

The plant is the first major new coal-fired power plant built in Indiana in more than two decades. Duke Energy received approval from the Indiana Utility Regulatory Commission (IURC) to build the IGCC facility in 2007. The plant was built on the site of a coal plant built in 1918 that is no longer operational. Three other operating units built there between 1944 and 1951 were retired in 2011.

But Duke’s $3.4 billion project has faced cost overruns and delays, as well as legal challenges and an ethical scandal. The company, which earlier this year completed a $32 billion merger with Progress Energy, had originally estimated project costs at $1.985 billion.

An April settlement proposed to end five years of litigation involving the Indiana Office of Utility Consumer Counselor, the Duke Energy Industrial Group (which consists of six of the utility’s large industrial customers), Nucor Steel, and Duke Energy put a $2.595 billion cap on project costs to be included in electric rates.

The IURC is reportedly updating the state’s rule governing how utilities develop long-term plans to meet power demand largely because of controversy tied to the Edwardsport cost overruns and ethics allegations. Public comments on the Integrated Resource Planning Rule have already been taken, and the state is expected to issue the final rule in a few months.

Sources: POWERnews, Duke Energy

—Sonal Patel, Senior Writer (@POWERmagazine)