Work proceeds on the steam turbine generator foundation for Mississippi Power Co.’s coal-gasification plant in Kemper County, Miss.
A massive 582-megawatt power plant under construction about 20 mi. (32 kW) north of Meridian, Miss., will use a combination of intense heat and high pressure to convert locally abundant lignite coal into a cleaner-burning gas that is then used to produce energy.
Mississippi Power Co.’s new $2.4 billion Kemper County power plant is so far on target to be completed on budget and begin operation by 2014.
Contractors are on schedule due to a construction timeline that planned for the extreme heat conditions and other weather-related issues they’ve encountered.
Work on the 2,968-acre job site began in June 2010, said Construction Site General Manager David Empfield, speaking in a video update on the project posted on Mississippi Power’s Web site.
Erosion control measures — which Empfield stated included installation of more than 60,000 linear ft. (18,288 m) of silt fencing and eight sedimentation ponds — are complete.
Timber removal and clearing/grubbing also have been completed, as has the majority of earthwork on the site.
Phase I and II of mass earthwork have been completed. Phase I alone entailed moving 2.5 million cu yds (1.9 million cu m) of dirt.
Phase III is under way with a total of 799,703 cu. yds. (611,416 cu m) hauled to date for the reservoir area.
The total plant site has about 4.5 million cu. yds. (3.4 million cu m)of dirt that need to be moved by mid-2012, Empfield said.
It will be a balanced cut and fill for the site. In some areas of the site, they have to cut 30 to 35 ft. (9 to 10.6 m) in depth, while in others they have to fill more than 50 ft. (15.2 m), Empfield said.
Concrete and underground work is now under way. Auger-cast piling installation is 26 percent complete, and caisson installation is 48 percent complete. Concrete work is proceeding, with 13,055 cu. yds. (9,981 cu m) of foundations poured.
Underground piping and electrical utility installation is in progress, with underground piping 21 percent complete.
More than 500 craft workers are currently on the job, with about four times that many expected at the peak of construction, the company said. A second shift will be used through the remainder of the project as required to support the schedule for activities that are considered critical.
Construction contractors on the job include: A E Allen of Pass Christian, Asplundh Tree Expert Co. of D’Iberville, Design Precast and Pipe of Gulfport, Dowdle Gas Company of DeKalb, East Mississippi Electric Power Association of Meridian, Fraley Dozer Service of Collins, Fulton Line Service of Preston, Herring Gas Co. Inc. of Philadelphia, Miss., Mississippi Department of Transportation, Perfect Touch Contractors LLC of DeKalb, ProModular of Jackson, RSC Equipment Rental of Meridian, Singley Construction Co. of Columbia, Vice Construction Co. of Moss Point, Wilkerson Construction of DeKalb and William Clay of DeKalb.
The plant is expected to provide about 300 permanent jobs once construction is complete, Mississippi Power said.
An army of heavy equipment — including bulldozers, track hoes, scrapers, cranes and dump trucks that are mostly being provided by the contractors — has been working on the project.
Various types of structures, including warehouses, maintenance shops, electrical buildings and administration/control buildings, as well as a network of access roads will be built on the site.
Work will continue on deep foundations, concrete foundations and underground utility activities through the remainder of 2011, the company said. Additionally, structural steel erection is scheduled to begin early in the last quarter of this year.
The plant is being built on Hwy. 493 near DeKalb, Miss. It’s a rural area without much traffic. Still, project coordinators have gone to great lengths to have the least impact possible on the surrounding community.
All lignite will be transported internally on the coal mine and plant site by trucks and conveyors that will not cross public roads. Natural gas will be routed to the site from the Tennessee Gas pipeline, which already exists near the property boundary.
“Safety at the site is a top priority. Our goal is for everyone to go home as healthy as the day they get here,” Empfield said.
STEP, (Safety Through Everyone’s Participation) a behavior-based safety program, has been adopted by Mississippi Power Co.’s parent company, Southern Company, to help eliminate unsafe work habits and hazards on the job with the goal of preventing injuries before they happen.
“The process begins with Southern Company construction management personnel and contractor supervision observing craft labor work habits and providing feedback to craftsmen on safe and at-risk behaviors,” Southern Company’s policy said. “Data is collected using checklists or mobile devices, input and analyzed to develop trends … that can be corrected before an incident may happen.”
The company’s target is no incidents, with a Recordable Incident Rate goal of 0.5 for this year. Southern Company credits the STEP program for helping to lower the Recordable Incident Rate to 0.47 with 12,500,000 work hours in 2010 for all Southern Company projects.
The Kemper County plant will use an IGCC (Integrated Gasification Combined Cycle) design called TRIG, developed over the last 15 years at a research facility for the Department of Energy and Southern Company in Wilsonville, Ala.
Rather than burning coal to make electricity, the IGCC process sends coal through a device called a gasifier that subjects it to high temperatures and high pressure to force a chemical reaction that creates a synthesis gas. The cleaner “syngas” is then used in a gas turbine to generate power with fewer emissions than traditional coal plants.
Unique to the TRIG process is a high-efficiency design that sends coal that is not converted to gas in the initial process back for a second round of gasification.
A multi-step process removes 90 percent of mercury, 99 percent of sulfur dioxide and 99 percent of particulate from the gas before it gets to the power generation phase. The IGCC technology also captures 65 percent of carbon dioxide, which is equal to similarly sized natural gas combined cycle plants.
The company has touted the plant as using “clean coal technology,” leading the way to lower-carbon electricity production by being one of the first in the country to provide carbon capture.
The plant will be a zero-discharge facility, meaning no processed water from it will be discharged into rivers, creeks or streams, according to the company.
Still, the plant hasn’t been applauded by environmentalists. The Mississippi Sierra Club fought the plant’s construction, claiming it is unnecessary and dirty and that it will prove costly to the utility’s ratepayers. The group believes natural gas would have been a better fuel source.
Mississippi Power does plan to pass on construction costs to its ratepayers, but it contends that the plant will be needed to meet an expected greater need for electricity by summer 2014.
By tapping Mississippi’s largely unused 4 billion-ton reserve of lignite, which is cheaper than traditional coal, the company said it can ensure reliability while avoiding highly volatile price swings for fuels such as natural gas, making it the best option for customers in the long run.
To offset construction costs, Mississippi Power has received a $270 million grant from the Department of Energy and $133 million in investment tax credits approved by the IRS provided under the National Energy Policy Act of 2005.
The company also applied for Department of Energy loan guarantees and has received an additional $279 million in IRS investment tax credits. CEG