Newdata released by the U.S. Energy Information Administration tracks thepollution controls that the nation's coal-fired power plants have installed inresponse to the U.S. EPA's Mercury and Air Toxics Standards.
The MATSrule was the first to regulate emissions of mercury and certain otherpollutants from coal- and oil-fired power plants. Power plants generally wererequired to begin complying with the regulation by April 2015, and while manyreceived extensions to 2016, only a handful were granted further extensions to2017.
TheEIA has now looked at how power plants have responded to the regulation thusfar in a new brief. According to data released July 7, coal-fired plants with87.4 GW of total capacity added pollution controls between December 2014 andApril 2016.
Atotal of 19.7 GW of coal-fired capacity retired in that time frame as well,exceeding the EPA's December 2011 estimatethat 4.7 GW of smaller and older coal-burning units would retire as a result ofthe rule. Overall, coal-fired generation capacity dropped from 299 GW at theend of 2014 to 276 GW as of April. Coal's share of total electricity generationdeclined from 39% in 2014 to 28% in the first four months of 2016.
Oneof the brief's authors, Sara Hoff, said the 276 GW of coal as of April includesany new coal additions, replacement of damaged units or units that may haveswitched from burning entirely wood to coal. The final number also includes anychanges plant operators may have made to capacity value reports, which may seemlike capacity additions but are merely adjustments.
TheEIA said the decline in coal-fired capacity has been caused by factorsincluding competition stemming from low natural gas prices as well as the costsand technical challenges associated with environmental compliance methods. Somecoal-fired power plants — 5.6 GW, according to the EIA — opted to switch tonatural gas. About 2.3 GW of coal-fired capacity received a second extension for the MATS rule and will need tocomply by 2017.
Byfar, the most dominant method of mercury control was activated carboninjection, or ACI, as 73 GW of coal-fired capacity installed such controls in2015 and 2016. The EIA said that effectively doubled the amount of coalgeneration with ACI controls in place. The ACI option was most popular becauseof its relatively modest costs, which the EIA estimated to be $5.8 million pergenerator over 2015 and 2016, on average.
Asfor other control options, operators of 12 GW of capacity installed scrubbersand 15 GW installed sorbent systems. Baghouses and selective catalyticreduction equipment were added by plants with 14 GW of capacity, and a further14 GW adopted "other compliance strategies." The EIA noted that somepower plants added multiple systems in an effort to comply with MATS.
Inall, the EIA said $6.1 billion was invested to comply with MATS or otherenvironmental regulations from 2014 to 2016. The EPA in December 2011 estimatedthat MATS compliance would cost utilities and potentially consumers $9.6billion per year.