Pollution Prevention
Emission reductions
The Tennessee Valley enjoys cleaner air today than it has in many decades, thanks in part to TVA’s continued commitment to reduce its emissions and their impact on the environment.
NOx emissions
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| Click chart for data. Prior to 2004, figures were based on calendar year. |
NOx Ozone Season emissions
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| Click chart for data. View 2006 revisions of target figures. |
SO2 Emissions
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| Click chart for data. View 2006 revisions of target figures. Prior to 2004, figures were based on calendar year. |
• In 2005, TVA had its lowest emissions of nitrogen oxides (NOX) and sulfur dioxide (SO2) on record despite generating the third-highest amount of fossil power in its 72-year history.
• Also in 2005, TVA reduced NOX emissions during the ozone season (May to September) by 80 percent below peak 1995 levels.
• Low-NOX burners or some form of improved combustion controls have been installed at every one of TVA’s 59 coal-fired units. In addition, selective catalytic reduction (SCR) systems for controlling NOX have been installed on 20 coal-fired units. These units represent 60 percent of TVA’s total coal-fired capacity. Additional systems will be installed in the future.
• TVA has also successfully demonstrated selective noncatalytic reduction technology at Johnsonville and Shawnee fossil plants and may use this technology as an interim step in achieving lower systemwide NOX emissions.
Sulfur dioxide emissions in 2005 were 80 percent below peak 1977 levels, and TVA is on track to achieve an 85 percent reduction by 2010.
• For controlling SO2 emissions, TVA uses several approaches, including flue gas desulfurization systems, or scrubbers, which are already operational on six coal-fired units.
• Two additional scrubbers are under construction: one at Paradise Fossil Plant, scheduled to be operational in late 2006, and one at Bull Run, scheduled for 2009. Two more will be added at Kingston and should be operational by the end of 2010. Evaluations are proceeding at other fossil plants for the addition of this technology.
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| Bull Run Fossil Plant Manager Nathan Burris speaks at the ceremony inaugurating construction of the plant’s scrubber. |
• TVA also achieves SO2 reductions through the use of low-sulfur coal.
Read more about TVA’s air quality initiatives.
Fine particle monitoring
For more than 25 years, TVA has monitored various air quality indicators in the Great Smoky Mountains National Park to help researchers understand regional haze in the Southeast. In the years since air quality research began, more attention has been focused on fine particles as our understanding of their effects on human health increases. TVA operates three fine-particle-monitoring stations and continues to be on the leading edge of this research. Data from these monitors are being analyzed in detail to determine how the composition of fine particles varies with the season, time of day, and weather conditions. These data, along with information provided by a nationwide monitoring program, reveal that levels of fine particles are improving and that the air quality in most areas meets the new, more stringent ambient air quality standard for fine particles issued by the Environmental Protection Agency (EPA). Read more about TVA’s research at Dust in the Wind. Also see EPA’s Clean Air Interstate Rule.
Climate change and CO2 emissions avoided
Carbon dioxide (CO2) is a greenhouse gas believed to contribute to global climate change. TVA reduces the intensity of its CO2 emissions in part through initiatives that increase power generation from nonemitting sources. These include:
• The restart of Unit 1 at Browns Ferry Nuclear Plant (near Athens, Alabama).
• TVA’s Green Power Switch program.
• The increase in the number of megawatts a hydro plant can generate as a result of TVA’s hydro power-train modernization program.
Since 1994, TVA has reduced, sequestered, or avoided in excess of 277.7 million metric tons (306.1 million tons) of CO2. In 2004, 39 percent of TVA’s total generation came from sources that do not emit CO2. In 2005, 38 percent of total generation was from non-CO2-emitting sources.
CO2 Emissions
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| Click chart for data. View 2006 revisions of target figures. Prior to 2004, figures were based on calendar year. |
TVA also participates in several partnerships that are pursuing ways to sequester or reduce the CO2 emitted to the atmosphere:
• Power Partners is a joint project between the Department of Energy and electric utilities to reduce the intensity of greenhouse gas emissions. The partnership supports voluntary efforts aimed at energy efficiency, increased investment in research and development, and cost-effective emission reductions. TVA provided input to a Power Partners resource guide that outlines approaches to reducing greenhouse gas intensity.
• PowerTree Carbon Company is a partnership of 25 power companies that are planting trees in the lower Mississippi River Valley. The companies have committed more than $3 million to plant trees that are expected to capture more than 1.5 million metric tons (1.6 million tons) of CO2 from the atmosphere as they grow and will also provide habitat for threatened and endangered species.
• The CO2 Capture Test Center is a joint effort with the Electric Power Research Institute and other utilities to design a transportable test unit that would evaluate CO2 capture technologies on units burning different types of coal. The unit will test newly developed solvents and components that have the potential to reduce the energy use associated with carbon capture.
Read about a TVA project at Paradise Fossil Plant to capture carbon and about TVA’s other carbon sequestration efforts. Also see the Southeast Regional Carbon Sequestration Partnership for information on regional efforts.
Use of coal combustion products
Utilization of coal combustion products
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Click chart for data. View 2006 revisions of target figures. |
Residues from burning coal and from emission-control processes, such as fly ash, bottom ash, and gypsum, have generally been stored in ash ponds or landfills at coal-fired plants. However, new methods of recycling and reusing these materials are being developed to keep them out of landfills. They’re used in products such as concrete block and wallboard, for example, and as a component in road construction. In 2004, TVA utilized 2.6 million metric tons (2.9 million tons) of coal combustion products and in 2005 increased the figure by nearly 7 percent, to 2.8 million metric tons (3.1 million tons).
TVA participates in the Coal Combustion Products Partnership, a cooperative utility effort that promotes the use of products from burning coal to reduce solid waste and CO2 emissions. Those emissions are reduced, for example, when fly ash is used as a replacement for Portland cement, the main ingredient in concrete. Cement production creates large amounts of carbon dioxide, and the use of fly ash in this application has the potential to reduce CO2 emissions by about nine million to 13 million metric tons (10 to 14 million tons) annually.
Demand-side management
Reduction of peak energy demand
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Click chart for data. View 2006 revisions of target figures. |
Number of energy-efficient new home installations
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Click chart for data. View 2006 revisions of target figures. |
Demand-side management helps consumers reduce their power demand by providing products and services that support energy efficiency. TVA and the distributors of TVA power offer energy-efficiency programs marketed under the brand name energy right®. The program:
• Promotes the construction of energy-efficient new homes and the installation of energy-saving heat pumps in existing homes and small businesses.
• Offers energy-management tools to help consumers analyze their power consumption and find ways to use it wisely.
These initiatives accounted for estimated reductions in power demand of 57.4 megawatts in 2004 and an additional 45.4 megawatts in 2005, and they have contributed to a cumulative demand reduction of 450 megawatts since 1996.
The energy right Program also promotes sustainable development. Energy right had certified 109 Energy Star homes in the Tennessee Valley through the end of the 2005 fiscal year. Read more about energy right.
Green Power Switch®
It’s getting easier to be green thanks to the 90 public power distributors in the seven-state Valley region that now offer consumers the option to purchase renewable energy under TVA’s Green Power Switch program. Launched in 2000 with 12 distributors, the program provides energy from solar, wind, and methane gas sources. Consumers can buy Green Power Switch in 150-kilowatt-hour blocks, and each block adds $4 to the monthly energy bill. Some recent program highlights:
• During 2004-05, students at the University of Tennessee voted to increase their facility fees to support renewable energy, making UT the largest purchaser of Green Power Switch in Tennessee with 3,375 blocks.
• Tennessee became the first state in the nation to buy green power for all of its state parks. Its purchase of 1,149 blocks per month is equivalent to the environmental benefits of planting 169 hectares (418 acres) of trees, recycling 8.8 million aluminum cans, or removing 270 cars from Tennessee highways.
• In 2004, TVA added a solar system at Bridges, a youth leadership training center in Memphis, and in 2005 TVA launched its 16th solar site at the Morgan County Vocational Technical School in Wartburg, Tennessee.
Another exciting development for the Green Power Switch program was the addition of 15 wind turbines to the three original turbines at TVA’s Buffalo Mountain site in east Tennessee. Dedicated on Earth Day 2005, the new turbines increased the generating capacity of the site to 29 megawatts, making it a major source of power for the renewable program and the largest commercial wind installation in the Southeast. TVA has a 20-year power purchase agreement with Invenergy, the energy company that developed and built the new turbines. The 18 wind turbines at Buffalo Mountain can generate enough power to serve about 3,800 homes.
Green power switch® blocks sold
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Click chart for data. View 2006 revisions of target figures. |
Some consumers are also becoming producers of green power when they sign up for the Green Power Switch Generation Partners® demonstration program. It allows homeowners and businesses that generate renewable energy to sell the power they produce. In summer 2005, Middle Tennessee State University (MTSU) inaugurated the first commercial-scale solar generating system and became the largest participant in Generation Partners. The MTSU system can generate 10 kilowatts of electricity, and it is also used as a research and testing tool with the university’s alternative-fuel vehicle program. At the end of fiscal year 2005, there were 15 Generation Partners sites and 24 power distributors in the program.
Solid waste going to landfills
Solid waste going to landfills
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| Click chart for data. The 2005 figure represents expanded reporting criteria for solid waste. The 2004 figure shows both actual waste generated and amount that would have been generated if 2005 criteria were used. |
TVA Buildings’ energy consumption Energy use in TVA’s standard buildings.
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Click chart for data. View 2006 revisions of target figures. |
Recycled-Content Items Purchased EPA-designated items with recycled content
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| Click chart for data. |
In fiscal year 2004, the amount of solid waste that TVA sent to landfills was 11,629 metric tons (12,819 tons), an increase of 1.4 percent over the previous year. The amount for 2005 was 22,061 metric tons (24,318 tons), a 90 percent increase over 2004. The 2005 figure is significantly higher because it represents an expansion of the reporting criteria for solid waste to include additional sources, such as wastes generated from projects conducted at TVA’s generation and transmission sites and wastes collected at TVA-owned public campgrounds. If the 2004 data were expanded to include the same sources as 2005, the result would show a 7 percent increase in solid waste tonnage going to landfills (the 2004 adjusted tonnage would equate to 20,562 metric tons, or 22,666 tons).
In fiscal year 2005, TVA recycled 1,636 metric tons (1,803 tons) of office products, a 13.5 percent increase from 2004. That included 79 metric tons (87 tons) of computers. In 2004, the figure was 1,441 metric tons (1,588 tons). TVA also supports sustainability by purchasing products that contain recycled content and meet the requirements of the Resource Conservation and Recovery Act (RCRA). In 2005, these purchases totaled $5.5 million (55 percent of total office product purchases), and TVA spent an additional $48.2 million on other recycled-content materials. In 2004, expenditures that met RCRA requirements totaled $5.8 million, or 54.3 percent of office product purchases of $10.6 million, and TVA spent an additional $44.6 million on other recycled-content material.
