Alcoa Warrick Power Plant
About Alcoa Warrick Power Plant
 
The Alcoa Warrick Power Plant is a division of Alcoa Power Generating Inc. (APGI), a wholly-owned subsidiary of Alcoa Inc. The generating facility, located along the Ohio River in Southwestern Indiana just east of Evansville, provides power to Alcoa Warrick Operations, one of Alcoa’s largest manufacturing facilities. Warrick Operations includes smelting, casting, rolling and fabricating of flat-rolled products used in the packaging and lithographic markets.
 
The Warrick Power Plant has four steam-powered turbines with a combined generating capacity of 791 megawatts. Alcoa Power Generating wholly owns three of the four generating stations, which were placed into service in the early 1960s. The largest unit, known as Unit 4, is jointly owned by APGI and Vectren Inc., a utility company. This larger unit was placed in operation in 1970.
 
The Power Plant is fueled by Illinois Basin coal that is mined from the nearby region, including Alcoa’s Friendsville Mine in Southern Illinois. That mine is operated by an independent company that is under contract by Alcoa. The generating station receives about 2 million tons of coal each year from both rail and truck shipments.
 
In addition to electrical power, the power plant also provides potable water, smelter steam and high temperature water across the plant. These services are critical to the various production processes throughout Warrick Operations.
 
Environmental Performance
 
The Alcoa Power Plant has sophisticated environmental controls. In December of 2008, Alcoa completed one of its largest capital projects in North America, an investment of more than $400 million to upgrade the Warrick Power Plant with wet-flue gas desulphurization equipment, or scrubbers. This control equipment significantly reduces sulfur dioxide emissions and went beyond what was required by rule or regulation. Vectren also contributed to the upgrades on its share of Unit 4, which the utility company owns 50-50 with Alcoa Power Generating Inc.
 
The environmental project began in 2005. At its peak, more than 500 construction workers were laboring each day at the site to construct the equipment that has helped further Warrick Operations’ reputation as an integrated, world-class aluminum production and fabricating facility. While the investment improved Alcoa’s environmental performance, it also enhanced power efficiency, lowered cost and helped provide long-term employment for the facility.
 
The environmental controls were installed on each of the four generating units in stages, and all of them went online at various times in 2008. The final scrubber unit was completed in December of 2008. The integrated environmental control system also included significant support facilities, including gypsum dewatering and handling facilities, dry-ash handling, new coal handling equipment and improved control facilities for the entire system. With the control systems fully operational and online in 2009, community leaders praised the results of the investment: More than a 95 percent reduction in sulfur dioxide emissions and impressive reductions in other compounds, too.

Construction work on the Warrick Power Plant's wet flue gas desulphrization equipment was completed in 2008 and was Alcoa's largest in North America at the time.

Three spray/absorption towers connect to the large chimney that serves generating units 1, 2, and 3 at the Warrick Power Plant. The Ohio River can be seen in the background.

In this large absorption tower, limestone slurry is injected into the exhaust stream to remove sulfur dioxide emissions from coal. Each of the four generating units has its own absorption tower. Electricity cannot be generated without the scrubber system operating.

An employee at the Warrick Power Plant inspects a control system on a large ball mill that grinds up limestone gravel. The pulverized gravel is then mixed with water to create a slurry, which is injected into the absorption towers.

A conveyor system transports wall-board quality gypsum, a beneficial byproduct of the scrubber process. Gypsum is a naturally growing mineral, and the synthetic form created during the scrubber process can be used for such beneficial uses as drywall and as a soil amendment to improve crop yields.