Kemper combined cycle achieves ‘world class level of reliability’

Mississippi Power estimates the reliability of Kemper’s combined cycle has saved customers about $15 million dollars in its first year of operation, thanks to the unit’s modern efficiency and low maintenance costs.

Since it began operation Aug. 9, 2014, the plant has been serving customers through some of the most frigid temperatures in years last winter, to some of the hottest heat waves this summer.

“I’ve been in the power industry for more than 30 years. I’ve worked around all sorts of power plants, but what Kemper has achieved is a world class level of reliability, especially for a new installation,” said Jeff Parsley, plant manager. “That outstanding rate means this plant is now typically available 99 percent of the time to provide our customers with reliable, affordable electricity.”

As a base-load plant — a flagship facility that runs almost all the time in order to meet daily power requirements — Kemper’s power output has now replaced that which had previously been derived from much older, less efficient facilities in the Mississippi Power fleet.

“After Hurricane Katrina, our company, and subsequently the Public Service Commission, saw a need for a newer base-load facility to continue the excellent reliability scores that our customers expect and for which our company is known throughout the industry,” said Allen Reaves, vice president of Generation and senior production officer. “Since it began serving customers last year, Kemper has more than demonstrated its ability to fulfill that goal.”

The combined cycle plant at Kemper combines two combustion turbines with one steam turbine — three engines that turn generators to produce electric power. The combustion turbines, which are akin to large jet aircraft engines, are running on natural gas as their fuel right now. However, when the Kemper County energy facility’s two lignite gasifiers begin operation, the combustion turbines will begin running on syngas derived from gasified lignite, a low-rank coal found abundantly throughout East Mississippi.

But that’s not all.

Not only does this plant have the ability to make its own fuel in the future from lignite, it’s already making some of its own fuel, thanks to the heat recovery steam generators now in operation.

In a combined cycle, this system allows plants to harness the heat from the exhaust of the combustion turbines to produce steam to power the steam turbine.

On top of that, when Kemper begins gasification of lignite, it will not only use the syngas from the lignite to power the combustion turbines, it will also use heat generated from the gasification process to make even more steam available for the steam turbine.

“Modern combined cycles just have a lot of flexibility, reliability and self-sustaining technology built into them,” Parsley concluded. “And this one has proven itself time and time again in its first year.”