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Emissions
Air emissions overview
Since 1990, PPL has reduced its air emissions. Significant reductions have been made in sulfur dioxide emissions and nitrogen dioxide emissions.
Significant additional reductions will be made in sulfur dioxide emissions as PPL’s new flue gas scrubbers go into operation at the Montour power plant in 2008 and at the Brunner Island power plant in 2009. When those projects are complete, all of PPL’s major coal-fired power plants will have scrubber technology. In addition, PPL retired two coal-fired generating units at its Martins Creek power plant in Pennsylvania during 2007 as part of a voluntary agreement to reduce sulfur dioxide emissions.
Mercury emissions from PPL fossil-fueled plants will be reduced as a co-benefit of scrubber technology.
Since 1990, PPL carbon dioxide emissions have increased by about 12.5 percent, primarily because of increasing power demand and because PPL acquired two coal-fired power plants from Montana Power Co. in 1999.
Currently, there are no systems commercially available for removing and disposing of carbon dioxide from coal-fired power plants. Government and industry carbon capture and sequestration research programs are under way in the U.S., Canada, Australia and Europe, with the goal to develop commercially available and cost-effective carbon removal systems for power plants.
Actions PPL is taking to prepare for reduced carbon emissions are discussed under the climate change section of this report.
Carbon dioxide emissions
PPL system carbon dioxide emissions in 2007 were 31.2 million tons. This was an increase of about 3.5 percent over 2006 emissions. The increase was the direct result of higher fossil-fueled generation to meet increasing power demand. PPL’s 2007 carbon dioxide emission rate also increased slightly, to 1,167 pounds per megawatt-hour, a 1.4 percent increase over 2006.
 
Sulfur dioxide emissions
PPL’s 2007 system sulfur dioxide emissions were 281,200 tons, an increase of about 4 percent over 2006. Because coal-fired generation increased only 0.3 percent in 2007, most of the sulfur dioxide emissions increase was likely because of increased sulfur content of the coal burned. PPL’s 2007 sulfur dioxide emissions rate of 10.5 pounds per megawatt-hour also increased slightly, by 1.9 percent over 2006 emissions.
 
Nitrogen oxides emissions
PPL’s 2007 system nitrogen oxides emissions were 46,500 tons. This was an increase of about 4 percent over 2006 emissions. This small increase could have been from a combination of different boiler or plant operational factors at PPL’s large fossil-fueled units. PPL’s 2007 nitrogen oxides emissions rate of 1.74 pounds per megawatt-hour also increased slightly, by 1.8 percent over 2006 emissions.
 
Mercury
The U.S. Environmental Protection Agency’s Clean Air Act regulations that limit mercury emissions from coal-fired power plants were overturned by a U.S. Court of Appeals. Unless the ruling is successfully challenged, the EPA must develop standards requiring maximum achievable control technology for mercury emissions.
Several states, including Pennsylvania and Montana where PPL owns and operates coal-fired power plants, have adopted more stringent mercury emission regulations. The U.S. court ruling is not expected to affect PPL’s current plans to comply with state regulations in Pennsylvania and Montana. PPL continues to review the federal court opinion to determine whether it has any effect on state regulations in the long term.
Because of the co-benefit in mercury reductions from the flue gas desulfurization equipment PPL is installing at the Montour and Brunner Island plants, PPL expects that it can achieve Pennsylvania’s 2010 first-phase emission requirements by adding chemical injection systems. PPL currently estimates that the capital cost of chemical injection systems at its Pennsylvania plants will be about $72 million if these systems are needed at both plants.
Because an emissions trading program is not allowed under Pennsylvania’s mercury rules, chemical addition systems may not be sufficient to achieve the Phase 2 Pennsylvania emission levels. Therefore, beginning in 2015, advanced fabric filter systems may be needed at most of PPL’s Pennsylvania coal-fired power plants. Based on current industry figures, PPL estimates that if this technology were required at all of its Pennsylvania units, PPL’s aggregate capital cost to comply with Phase 2 would be about $530 million.
In Montana, PPL plans to install chemical injection systems to meet the state-specific 2010 reduction requirements. PPL estimates that its share of the capital cost for these systems would be about $8 million. Because chemical injection technology may not be sufficiently developed to meet the 2010 Montana rules, there is risk that PPL may need to install advanced fabric filter technology at both the Colstrip and Corette power plants. PPL estimates that if this technology were required at its Montana units its share of the capital cost would be about $140 million.
Toxics release inventory
 The Toxics Release Inventory (TRI) is a federal program under which industrial facilities (including power plants) report their air, water and soil releases. The U.S. Environmental Protection Agency maintains a database of more than 650 chemical substances emitted from industrial facilities under the TRI program. Some TRI substances occur naturally in coal. PPL's emissions of substances listed in the TRI have gradually increased in recent years due to an increase in power plant generation and use of increasing amounts of coal. As power generation increased, some previously non-reportable trace substances have met the reporting threshold requirements and have been added to the reportable quantities.
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