Dive Brief:

• Mississippi Power has pushed back the start date for its 582 MW clean coal project under construction in Kemper County, Miss., by one month to Dec. 31, 2016.

• The utility also added $25 million to its cost estimate to cover the schedule extension.

• Mississippi Power says the extension is needed because it is taking one of the two gasifiers out of service in order to make improvements on its ash removal systems.

Dive Insight:

Mississippi Power’s integrated gasification combined-cycle Kemper project ran into trouble almost from its outset. Most recently the utility pushed forward the start date to Nov. 30, from Oct. 31, and added $33 million to its cost.

If Mississippi Power is not able to bring the plant online by year end, it would be at risk to repay $250 million in tax benefits it has already received.

The project is designed to convert local lignite coal from mines owned by Mississippi Power’s corporate parent, Southern Co., into a synthetic gas. The gas burns cleaner than coal, producing about 65% less carbon pollution.

The project was originally estimated to cost about $2.9 billion and be online in 2014. The most recent addition brings puts the total cost to $6.925 billion.

Mississippi Power says the most recent cost overruns will be paid by Southern and Mississippi Power, not by ratepayers.

The last schedule extension was also due to ash buildup in one of the two gasifiers, which entered service in July, and September. The plant has been generating electricity since 2014, but only started running on synthetic gas last month. 

Once the Kemper plant is operational, Southern hopes to commercialize its coal gasification technology to license and sell to other companies.