Generation Units at OUC's Stanton Energy Center
The Curtis H. Stanton Energy Center is a strategically phased "powerhouse" comprising a portfolio of clean, modern, fuel-diverse environmentally sound power-generation equipment. Newsweek magazine has described it as "non-polluting." Others just call it a good neighbor. With good reason: When it comes to protecting the environment, OUC goes above and beyond — always using the best technology available at the time of construction.
The Curtis H. Stanton Energy Center’s Unit I began operating in 1987 to meet the growing electricity needs of Central Florida. Unit II began operating in 1996. The coal-fired units have enabled OUC to reduce its dependency on oil and gas and give it the fuel flexibility to provide customers with the best reliability and some of the lowest electric rates in Florida.
Coal is sent to the boiler where it is burned, causing some of the water flowing through the walls of the boiler to become steam. The steam is then separated from the water and heads out of the boiler at about 1,000 degrees Fahrenheit on its way to the turbine. As the steam passes through rows of blades, the energy of the steam causes the turbine to spin. The generator rotor is directly connected to the turbine, and as the turbine spins, a magnetic field is applied to the generator rotor. The spinning of the magnetic field inside the generator is what produces electrical energy.
Zero-Water Discharge Facility
State-of-the-art pollution control equipment used by the Stanton Energy Center enables the plant to operate as a zero-water discharge facility.
The Stanton Energy Center gets most of the water it needs from Orange County’s Eastern Wastewater Treatment Facility. About 10 million gallons of water is pumped to the site each day and eventually evaporated through the cooling towers.
While re-using this water that otherwise would end up in the Econlockhatchee River, OUC reduces the demand on our precious groundwater supply. Rain runoff on the site is diverted to holding ponds for re-use.
Groundwater monitoring wells around each pond verify that none of this water leaks into the surficial aquifer. This water is used in the pollution control process, and every day about 925,000 gallons eventually evaporate from the tall stacks.
To prevent air pollution, SEC uses low-sulfur, low-ash coal and operates state-of-the-art pollution control equipment to remove pollutants. State-certified instruments continuously monitor emissions to verify actual removal. The Florida Department of Environmental Protection reviews air-monitoring data from SEC. Air sampling has shown that Stanton’s emissions are among the lowest of any coal-fired plant in the nation.
Environmental Protection Measures
Coal burning in the boiler creates gaseous and particulate (solid) byproducts called flue gas. Particulates, Nitric Oxides (NOx) and Sulfur Oxides (S02) are present in the flue gas. Emissions of these byproducts are monitored closely by the Stanton Energy Center to ensure adherence to established governmental environmental standards.
Unit 2: NOx is controlled by efficient low-NOx burners and Selective Catalytic Reduction equipment (Unit I also uses low-NOx burners). Burners are designed to minimize NOx by burning at low temperatures, with a minimum amount of turbulence, utilizing as much time as possible to complete the burn. The Selective Catalytic Reduction process converts NOx to harmless Nitrogen (N2) and water (H2O) by spraying Ammonia (NH3) into the flue gas and allowing the flue gas to pass through a catalyst material to enhance the chemical reaction.
Units 1 and 2: Particulates are controlled in an electrostatic precipitator. This equipment electrically charges the solid particles (fly ash) so that they will be attracted to oppositely charged plates. Large hammers periodically hit the plates causing the fly ash to fall to the bottom of the precipitator so that a vacuum system can transport it for storage in a silo.
S02 is controlled by a wet limestone scrubber. In the scrubber, a limestone and water slurry (scrubber slurry) is sprayed over the flue gas. The S02 reacts chemically with the limestone and water slurry in the flue gas and becomes a suspended solid in the scrubber slurry. As this process continues, the scrubber slurry increases in solid content and becomes more acidic. To maintain this chemistry in a balance, spent scrubber slurry is removed as new fresh slurry is added. The spent scrubber slurry is transported away for the disposal process.
The fly ash removed in the electrostatic precipitator and the spent scrubber sludge from the flue gas scrubber are mixed with lime. The addition of lime to this mixture causes the material to harden much like concrete. This material is transported to the Combustion Waste Storage Area near the western boundary of the site. After placement, this material is compacted, contoured, covered with topsoil and seeded.
Material deposited in this landfill is environmentally stable. Since it is essentially impervious, it will not contaminate the groundwater. Monitoring wells are placed throughout the site to ensure that the groundwater has not been contaminated.
Both Stanton Units 1 and 2 were ahead of their time in terms of advanced environmental technology. Today, both continue to be better than they have to be when it comes to meeting air quality standards. According to federal monitoring agencies, these units are among the most environmentally sound coal-burning operations in the nation. We plan to keep them that way by continuing to modernize them with advanced technologies that optimize efficiency, environmental performance and operating flexibility.
Stanton Unit 1
- Began commercial operation in 1987.
- Full generating capacity: 444 megawatts.
- ·Coal-fired unit equipped with state-of-the-art environmental protection equipment designed to thoroughly cleanse combustion gas before it enters the chimney.
- No measurable impact on the air, according to continuous air quality monitoring.
- Continues to demonstrate superior performance.
Stanton Unit 2
- Began commercial operation in 1996.
- Full generating capacity: 446 megawatts.
- First pulverized coal unit of its size in the nation to use Selective Catalytic Reduction to remove nitrogen oxide — meeting and exceeding all federal regulations for air quality.
- Continues to exceed federal and state environmental requirements.
A combined cycle power-generation facility, Stanton A helps OUC maintain stable power prices by further diversifying our fuel mix and maintaining flexibility through the use of purchased-power agreements.
- Began commercial operation in 2003.
- Full generating capacity: 633 megawatts.
- Combined cycle plant that includes two natural gas-fired combustion turbines, two heat-recovery steam generators and a steam turbine.
- Developed in joint partnership with Atlanta-based Southern Company.
- Features the most environmentally advanced technology available, minimizing emissions and generating electricity 30 percent more efficiently than earlier technologies.
- OUC owns nearly 1/3 of Stanton A's output. The Kissimmee Utility Authority and Florida Municipal Power Agency each owns 3.5%, and Southern Company owns the remaining 65%.
- Began commercial operation in February 2010.
- Full generating capacity: 300 megawatts.
- Combined cycle plant that includes one natural gas-fired combustion turbine, one heat-recovery steam generator and a steam turbine.
- Features the most environmentally advanced technology available.