* More than 30 GW of coal power to shut nationwide
* MISO could lose 12-19 GW of coal power in a few years
By Scott DiSavino
May 11 (Reuters) - Energy companies in the U.S. Midwest will face significant costs and challenges to either upgrade their coal-fired power plants or build new natural gas units in order to meet new federal environmental rules, according to a report for the region's power grid operator Friday.
In addition to the upgrades, several dozen older coal-fired plants, capable of generating 12,000 to 19,000 megawatts (MW), could shut over the next several years, said economists at the Brattle Group, the consulting firm that conducted the study.
Power companies across the nation are struggling to figure out how to make increased infrastructure investments that will be necessary to comply with stricter federal environmental rules that become effective in April 2015 and still maintain reliability of the electric grid.
The Brattle study was commissioned by the Midwest Independent Transmission System Operator (MISO), which operates the power grid for 11 U.S. Midwest states and the province of Manitoba in Canada.
"Overall, it will be a major challenge for the industry, states, and MISO to comply with (federal mercury emissions rules) for a number of reasons," Metin Celebi, a Brattle principal and lead author of the study, said in a statement. Federal regulators are also struggling with the issue.
The report looked at what would happen if a large number of retrofits were needed at existing Midwest coal plants and new generation was needed at the same time to replace retired coal units to comply with the U.S. Environmental Protection Agency's (EPA) Mercury and Air Toxics Standards (MATS) rule.
"Generators of electricity should not be put in a position of having to choose whether to violate the Federal Power Act or the Clean Air Act when certain generating facilities are needed for crucial electric reliability needs," Philip Moeller, a Commissioner at the U.S. Federal Energy Regulatory Commission (FERC), told a Subcommittee on Energy and Power at the U.S. House of Representatives earlier this week.
The study found the projected number of coal retrofits and new generation needed to replace retiring coal units would exceed the historical maximum achieved for deployments of retrofits and new builds by 51 to 162 percent.
"We believe that the EPA estimates may be optimistic while industry estimates may be pessimistic, especially in the highest retrofit cases," Brattle's Celebi said.
Energy companies across the United States have already announced the retirement of over 30,000 MW of coal-fired power plants due to the stricter federal and state environmental rules, low natural gas prices that allow gas plants to displace coal plants, and weak power market and economic growth forecasts.
Factbox on coal units to retire, see
MISO has more than 114,000 MW of generating capacity, including about 72,000 MW of coal-fired plants.
MISO officials have said about 10,000 MW of the coal units were already compliant with environmental regulations, about 28,000 MW required "minor" upgrades and about 21,000 MW would require "major" upgrades. The remaining 13,000 MW could retire.
For those looking to keep their coal plants, Brattle said some minor environmental upgrades could be completed before 2015 without difficulty, but most major work and the construction of new natural gas plants to replace retiring coal units could take three to four years or more.
That means some projects may not be completed by the MATS compliance date of April 2015 even with a one-year extension.
"The industry will need to install retrofits at a pace and scale that exceeds the historical demonstrated capability," Celebi said.
The biggest power companies in the MISO are units of DTE Energy Co of Michigan, Duke Energy Corp of North Carolina, CMS Energy Corp of Michigan, Xcel Energy Inc of Minnesota and Ameren Corp of Missouri.