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Co-op uses technology to reduce mercury emissions

A wheel loader putting a bucket of additive into the coal supply to reduce mercury emissions.
A wheel loader putting a bucket of additive into the coal supply to reduce mercury emissions.
Associated Electric Cooperative has reduced mercury emissions voluntarily and ahead of regulations
  • Associated Electric has been reducing mercury emissions from its coal plant emissions for several years.
  • Our coal plants switched in 1994 to burning low-sulfur western coal, which is lower in mercury too.
  • We broke ground as the first to reduce mercury with innovative mercury removal technology.
  • Additional investments have achieved an overall reduction in mercury emissions of 85 percent since 2010 baseline data.
  • Associated's mercury emissions are below the MATS requirements.

Associated Electric led testing of a technology to reduce mercury emissions as the first utility to burn refined coal produced by Clean Coal Solutions LLC as a possible low-cost environmental solution.

Staff also researched and installed refined coal technology on Associated Electric's largest coal unit to reduce mercury emissions. Thomas Hill Unit 3 is a pulverized unit that uses a different type of CyClean refined coal technology that was commissioned in early 2015.

Today, the refined coal technology Associated Electric helped bring to market is reducing mercury emissions at the cooperative’s coal plants. It’s also a lower-cost technology that helps Associated Electric meet the Environmental Protection Agency’s Mercury and Air Toxics Standards, effective in April 2016.

MATS requires power plants to significantly reduce mercury emissions for the first time ever. Associated Electric, however, has reduced emissions of sulfur dioxide and nitrogen oxides up to 90 percent – as well as reduced mercury – since 1994 with its $1.1 billion investment in environmental controls and research technologies.

Part of the cost and reduced emissions are from switching in 1994 to low-sulfur western coal, which is lower in mercury. Associated Electric has invested in environmental controls, like overfire air and selective catalytic reduction equipment on all coal units, and made good business decisions that position it to provide clean, affordable and reliable electricity for its members.

 

What is mercury?

Mercury (Hg) is a naturally occurring metal in the Earth’s crust that is released into the environment from both natural and human activities. Natural sources include volcanoes, forest fires, oceans and soils. Human activities include gold and ore mining, medical waste incineration, municipal and hazardous waste combustion, cement manufacturing and fossil fuel combustion.
 
Trace amounts of mercury are present in fossil fuels, such as coal and oil. When electric utilities burn these fuels to generate electricity, mercury is released. U.S. electric utilities emit about 40 percent of domestic manmade mercury emissions and about 1 percent of total global mercury emissions.

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