* Plant virtually complete, costs $3.3 billion
* Duke retired three old coal units at plant in 2011
* Tells public flares will be seen, heard during testing
By Scott DiSavino
Oct 18 (Reuters) - U.S. power company Duke Energy Corp said construction of its 618-megawatt (MW) Edwardsport coal-fired power plant in Indiana was "virtually complete" and testing was under way to prepare the facility to begin operating next year.
The $3.3-billion plant has produced electricity using natural gas, and was close to running coal through gasification equipment, Duke said in a statement earlier this week.
Edwardsport is one of just a few integrated gasification combined cycle (IGCC) plants in the United States. IGCC technology converts coal into synthetic gas that is burned in the gas turbines to make electricity. The gasification process strips out pollutants such as sulfur from the coal before burning the gas.
Over the summer, Duke said it would delay commercial operation of the Edwardsport plant from September to 2013. Since it was first proposed, the estimated cost of the project has increased from about $1.98 billion to about $3.3 billion now, which includes financing.
Indiana regulators approved Duke's proposal to build the new plant at Edwardsport in 2007. That plan included the retirement, in 2011, of three small coal-fired units at the 160-MW site that were built in the 1940s and 1950s. Edwardsport is located about 100 miles (161 km) southwest of Indianapolis, the Indiana state capital.
The company issued the statement this week to notify the public that they may see a bright, and somewhat loud, gas flare from the plant, which will be especially noticeable at night.
If the synthetic gas produced in the gasification process does not meet certain standards, Duke said the gas will be diverted to the gas flare tower on the plant property, where it will be ignited and burned safely.
The company has not yet run coal through the gasification equipment, so there have not been any flares, Angeline Protogere, a spokeswoman at Duke, told Reuters Thursday.
Duke said the gas flare will also be used during each start-up and shut-down of the plant.
The flare will last only as long as it takes to shut down the coal gasification process, usually less than 30 minutes.
"I want to emphasize that whenever the gas flare is activated, it does not indicate any emergency at the plant," Edwardsport Plant Manager Jack Stultz, said in a statement.
"It is a normal part of plant operations. Because the gas flare may need to be activated quickly, we won't be able to provide advance notice to local residents. We appreciate everyone's understanding and patience," Stultz said.
There will be gas flare events during the testing and start-up process over the next several months. The plant will also use the flare during regular commercial service, but it should not be as frequent as during testing and startup, Duke said.
Charlotte, North Carolina-based Duke Energy's Indiana unit supplies power to about 790,000 Indiana customers and owns about 6,800 MW of generating capacity.