TVA Ahead of the Pack in Pollution and Pollution Reduction

Stephen Smith | January 14, 2011 | Coal, Energy Efficiency, Energy Policy, Utilities

The Tennessee Valley Authority (TVA) issued a January 6, 2011 release that uses a recent study by the Environmental Protection Agency (EPA) to highlight TVA’s successful reductions of dangerous air pollutants. The fact that TVA has reduced its air pollution is, of course, good news. It means that people and the environment in the Southeast are now exposed to fewer pollutants than they were in years past. Nonetheless, when TVA’s statistics are put into the proper context, it becomes clear that these large reductions are the result of extraordinarily high historic levels of pollution at TVA, rather than some extraordinary effort to aggressively reduce pollution in comparison to neighboring utilities. The real story here is that the Clean Air Act works, and should not be weakened.

arp4_coverEPA’s report, which was released in a series of three publications from August through December of 2010, documents the success of the Clean Air Act Acid Rain Program. The Acid Rain Program sets goals and establishes regulatory mechanisms for reducing the two chemical precursors to acid rain, sulfur dioxide (SO2) and nitrogen oxides (NOx).  These mechanisms, including the first “cap-and-trade” system in the United States, have worked to successfully reduce these pollutants by significant levels across the United States.

In complying with the Clean Air Act, TVA has achieved reductions in both SO2 and NOx. Nationally, SO2 emissions have decreased 67 percent since 1980. TVA, however, lowered SO2 emissions by 87 percent. Likewise, we have experienced a 77 percent reduction in NOx nationally since 1990, while TVA reduced NOx pollution by 86 percent.


Pollution reductions over the past three decades are primarily attributable to two air quality technologies: flue-gas desulfurization (FGD, or scrubbers), the best available technology for reducing SO2; and selective catalytic reduction (SCR), the best NOx control technology.

Most TVA coal plants consist of several energy producing “boilers” in which coal is burned. For example, TVA’s Kingston coal plant has nine boilers. TVA has a total of 59 boilers at 11 coal plants spread over Alabama, Kentucky and Tennessee. TVA has working scrubbers on eight of these boilers: Cumberland and Bull Run in Tennessee have scrubbers on all of their boilers, Widows Creek in Alabama has scrubbers on two of its eight boilers, and Paradise in Kentucky has scrubbers on all three boilers. At Kingston, in Tennessee, TVA is completing the process of installing two scrubbers that will control all nine boilers.

SCRs technology is more prolific in the TVA territory. TVA has installed SCRs on 21 boilers: all nine at Kingston, the one boiler at Bull Run, both boilers at Cumberland, all three boilers at Allen, also in Tennessee, all three boilers at Paradise, two boilers at Widows Creek, and one boiler at Colbert in Alabama.

These technologies have helped TVA achieve their recent pollution reductions – this is indeed good news. But it is important to place these reductions in the proper context. The baseline emissions rates that served as TVA’s ‘starting point’ were much higher than those at other regional utilities. Therefore, a higher percentage-based reduction does not necessarily mean that TVA is now emitting less than other utilities. Consider the television show Biggest Loser – if there are two contestants, one weighs 400 pounds and one 200 pounds, and each loses 10 percent of their body weight, the 400-pound contestant will lose 40 pounds and still weigh 360 pounds, while the 200-pound contestant, who loses only 20 pounds, now weighs a much healthier 180 pounds. If the contestants’ target weight is 180 pounds, the 400-pound contestant would need to lose 55 percent to get to that 180-pound target. The contestant with the more unhealthy starting point must achieve a higher loss percentage, for sure, to end at the healthy weight of 180 pounds.


TVA is in much the same situation as the 400-pound contestant in our example. 1980 was the earliest year for which EPA has data on SO2, and the first year the pollutant was federally regulated. That year, TVA emitted over 3 billion pounds of SO2.  This translates to 3.89 pounds per mmBtu (a measurement of heat input into a coal plant). In comparison, Progress Energy plants in North and South Carolina produced just one-third the pollution of TVA at 1.38 pounds of SO2 per mmBtu. Southern Company plants in Georgia, Florida and Alabama fell between TVA and Progress, with 2.73 pounds per mmBtu, as did Duke Energy plants in the Carolinas, which emitted 1.60 pounds per mmBtu.

The data is similar for NOx: 1995 is the earliest year for which EPA has NOx data available and it was the beginning of federal NOx regulation. In 1995, TVA emitted over 1 billion pounds of NOx, or 0.98 pounds per mmBtu. Southern Company emitted only 0.51 pounds per mmBtu, Progress emitted 0.84 pounds per mmBtu, and Duke emitted 0.90 pounds of NOx per mmBtu.

An analysis of current pollution rates shows that even with considerable reductions, TVA is still at the top of the pack. TVA emitted 0.56 lbs of SO2 per mmBtu and 0.16 lbs of NOx per mmBtu in 2009. Duke, the least dirty utility in the region, produced just 0.30 lbs of SO2 and 0.11 lbs of NOx per mmBtu that same year. Progress was similarly situated with 0.50 lbs of SO2 and 0.14 lbs of NOx per mmBtu.

The fact that Duke and Progress, both operating in North Carolina, have done relatively well reducing pollution is further evidence that clean air laws, such as the North Carolina Clean Smokestacks Act, really do work to reduce pollution. Southern Company, on the other hand, has fallen behind TVA and now has the dirtiest operations. Southern Company produced 0.89 lbs of SO2 and 0.16 lbs of NOx per mmBtu in 2009.


When we look at these statistics in terms of amount of pollution per mmBtu, it becomes clear that, despite their improvement over the past 30 years, TVA and Southern Company must still make very deep pollution reductions just to catch up with their peers in the region. They still have a ways to go before they can call themselves “healthy.”

All this data demonstrates that TVA has been able to reduce its pollution by such a large percentage because TVA had so much more room for improvement than their peers – they began with a coal fleet that was much dirtier than others in the region. While TVA deserves praise for their efforts, TVA and other regional utilities must continue cleaning up. EPA is preparing to announce final rules to further reduce NOx and SO2. These rules will probably establish new caps and trading programs for these pollutants. This will force TVA to decide whether to invest in further pollution control technologies or to retire their oldest, dirtiest and least efficient plants.

It is no coincidence that TVA has already installed advanced pollution control technologies on their most efficient and most utilized plants, such as Cumberland and Bull Run, and has left older and dirtier plants like Widows Creek and Johnsonville without advanced pollution control technologies. Investing hundreds of millions of dollars on new pollution controls simply doesn’t make economic sense for the large portion of TVA’s coal-fired generation fleet that is more than 50 years old.

TVA's Johnsonville Plant in New Johnsonville, Tennessee
TVA's Johnsonville Plant in New Johnsonville, Tennessee

Through its Integrated Recourse Plan, TVA is contemplating retiring old, dirty and inefficient coal plants, and has already made modest commitments to partial retirements at Shawnee in Kentucky, Widows Creek, and John Sevier. Neighboring utilities have also made retirement announcements, and although TVA’s current plans lag behind these neighbors, we expect TVA to make further commitments in the near future.

In order to protect ratepayers from rate increases and the environment from further pollution, and to comply with federal requirements, TVA should continue down this path and fully retire their oldest, dirtiest and least efficient plants. Widows Creek and Johnsonville should be at the top of that list. If TVA were to permanently shutter these two plants, they would reduce their SO2 emissions by an additional 23 percent and their NOx emissions by another 20 percent. TVA could then replace these facilities with a cleaner energy source mix, including energy efficiencysolar, wind, biomass and gas.

We applaud TVA’s progress to date, and are pleased with EPA’s report highlighting the successes of the Clean Air Act. But the extraordinary pollution that has historically been released at TVA’s coal plants remains a terrible human health threat and environmental legacy that has scarred peoples’ lives, damaged treasured place like the Great Smoky Mountain National Park, and contributed significantly to our atmospheric burden of carbon.

Yes, TVA has made progress, but we look forward to many more advancements. We expect our regional utility to lead the Southeast and to be ahead of the pack in clean air, clean energy, and coal plant retirements.

Stephen Smith
Dr. Stephen A. Smith has 30 years of experience effecting change for the environment. Since 1993, Dr. Smith has led the Southern Alliance for Clean Energy (SACE) as its executive…
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