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In the last 30 years, Detroit Edison has dramatically reduced emissions while customer demand for electricity has escalated. Approximately 80 percent of our annual electricity production is generated from fossil fuel, primarily coal. Our Fermi 2 nuclear plant accounts for most of the remaining generation. Our 30-plus year track record shows dramatic reductions in regulated air emissions. At the same time, customer demand has accelerated. |
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Detroit Edison has reduced annual particulate matter (PM) emissions 87 percent, sulfur dioxide (SO2) emissions 61 percent and nitrogen oxide (NOX) emissions 59 percent below 1974 levels. During this same period, total generation increased 53 percent. We submit each year's Toxic Release Inventory (TRI) information in June of the following year. As expected, there are variations each year in the emissions due to the concentration of elements in the coal and the amount of electricity generated. View the full TRI report here. |
As part of the EPA Acid Rain program, continuous emissions monitoring of CO2, nitrogen oxides (NOX) and sulfur dioxide (SO2) has been conducted since 1995. EPA regulations specify how each monitor must be operated and data quality requirements. Affected utilities must submit quarterly reports to the EPA. Reports are available from the EPA Clean Air Markets Division for each utility unit nationwide.
Detroit Edison burns 79 percent more coal today than 30 years ago. The company burned 12.3 million tons of coal to generate electricity in 1974. All of this coal was from the eastern U.S. Shortly thereafter, the company switched from using all eastern bituminous coal to a blend of eastern bituminous and western sub-bituminous coals to reduce SO2 emissions. Today about 70 percent of the 22 million tons of coal burned in Detroit Edison power plants is lower sulfur western coal.
Overall coal consumption grew rapidly between 1974 and 1987 due to a large increase in customer demand for electricity. Another contributing factor is the heating value of western coal - more coal must be consumed to produce the same amount of heat for steam generation. Within our fuel mix our annual coal consumption has averaged 20.4 million tons per year since 1987.
Detroit Edison coal consumption is expected to remain relatively flat in the future (plus or minus 1 million tons). Any increase in the percentage of western coal used or additional load growth could raise total consumption.
Detroit Edison generated about 35,000 gigawatt hours (GWh) of electricity in 1974, which is equivalent to 35 billion kilowatt hours (kWh). All this electricity was produced from the combustion of fossil fuel.
Fossil generation peaked in 1987, the same year the Fermi 2 nuclear unit began commercial operation. Detroit Edison produces as much electricity as possible from nuclear generation and the remainder with fossil generation.
In 2007, nuclear generation and fossil generation were somewhat lower than year 2000 generation as a result of a continued delay in economic recovery in Michigan, loss of customers due to Electric Choice and other factors.
Carbon dioxide emissions are directly related to the amount of fossil fuel (coal, oil, natural gas) consumed in a given year. Emissions of CO2 are not limited or capped under current federal or state regulatory programs.
In 1974, CO2 emissions from Detroit Edison power plants totaled about 35 million tons. This increased to about 49 million tons in 1987, when fossil generation peaked. In 2007, Detroit Edison power plants emitted almost 46 million tons of CO2 - a 33% increase from 1974, but a 4% decrease from 1987.
There is currently no emission control technology available to cost-effectively remove CO2 from power plant emissions; however, Detroit Edison is taking several voluntary actions to reduce, avoid and sequester greenhouse gases.
In the 1970s, Detroit Edison pioneered the use of low-sulfur western sub-bituminous coal to reduce SO2 emissions. At that time, all of Detroit Edison's coal-fired power plants were designed to burn eastern high-sulfur bituminous coal. Emissions of SO2 in 1974 were about 600 thousand tons.
Thirty years later, in 2007, approximately 70 percent of the 22 million tons of coal burned at Detroit Edison power plants was western sub-bituminous coal. Sulfur dioxide emissions were 233 thousand tons - a 61% reduction from 1974.
Nitrogen oxides are a product of fossil fuel combustion. As more coal is burned, NOx emissions increase. This was the historical trend in NOx emissions from Detroit Edison power plants during the 1970s and 1980s. In 1974, Detroit Edison NOx emissions were about 165 thousand tons, which grew to nearly 193 thousand tons in 1987.
The 1990 amendments to the Clean Air Act established the Acid Rain Program to reduce power plant NOx and SO2 emissions. Low NOx emission burners were installed at Monroe Power Plant in the mid-1990s (five years before the compliance deadline) to satisfy these requirements.
In recent years, Detroit Edison has invested more than $550 million in additional NOx control technology to meet the new EPA reduction requirements at its power plants. In 2007, Detroit Edison NOx emissions were about 67,400 tons - a 59% reduction from 1974 and 65% reduction from 1987 levels.
When Detroit Edison moved away from using strictly bituminous coal in the 1970s, it was necessary to upgrade some particulate control (removal) equipment. Particulate matter emissions in 1974 were estimated at just over 25,000 tons. In 2007, these emissions were about 3,300 tons - an 87% reduction from 1974.
From 1974 through 2005, Detroit Edison voluntarily took steps to reduce mercury emissions even though there were no specific environmental regulations that required it. As a result of our aggressive move to low-sulfur western coal and our supplier's actions to better clean eastern coals, total power plant mercury emissions in 2007 were about the same as those in 1974 despite the 79% increase in coal consumption. Detroit Edison is developing means for future reductions in mercury emissions to meet the requirements expected under future state and federal rules to reduce mercury legislation.
