Coal provided approximately 60% of Michigan’s electricity from 2001 to 2010, and peaked in 2009 at 66%. But a mix of increased competition from less expensive natural gas, a blend of subsidies and state-level mandates for renewable energy sources and increasingly heavy environmental regulation all took a heavy toll on coal use in Michigan. These pressures, along with increasing public pressure to switch to different fuels, caused total coal-fired generation in the state to decrease to 36.5% in 2018.
Michigan’s coal use began to drop in 2010 off as utility planning committed to close the state’s coal-fired generation capacity and replace it with a mix of energy efficiency, demand response, conservation measures and the construction of new natural gas and renewable capacity. Citing a mix of regulatory, market and social pressures, DTE has stated that it plans to close all of its coal plants by 2040 as part of its efforts to achieve net-zero CO2 emissions by 2050.
Consumers Energy made similar reductions in its coal-fueled generation fleet when, in 2016, it closed its “Classic Seven” coal plants, representing 950 megawatts — two units at the B.C. Cobb Plant, three units at the J.R. Whiting Plant and two units at the Karn-Weadock Plant. They have expanded on this plan with the MPSC’s approval of their Integrated Resource Plan in June 2019. Now referred to as their 2019 Clean Energy Plan, this document commits the utility to closing all of their coal-fired generation by 2040, the construction of over 6,800 MW of solar and wind generation facilities, and implementing an aggressive mix of demand response, conservation and energy efficiency measures. As noted above, the company has also committed to achieving net-zero CO2 emissions by the year 2040.
As also noted above, WEC Energy closed the coal-fired Presque Isle plant near Marquette in April 2019. Upper Michigan Energy Resources has completed construction of two natural gas generation stations to replace Presque Isle.
The benefits of using coal include its abundance, ease of shipping and use, and relatively low cost, with currently operating plants producing substantial amounts of reliable electricity at rates as low as $38.40 per megawatt-hour.
Coal-fueled generation units have also provided a substantial level of system stability to the state and national electrical grid, due to their size and the fact that they are designed to run almost continuously — as baseload generation resources, with capacity factors as high as 80%, significantly more than wind or solar. Energy industry and government experts have expressed concerns that the rapid closure of numerous coal plants could cause problems with overall grid stability, especially during times of high demand such as extreme hot or cold weather.
The challenges associated with using coal to produce electricity primarily relate to addressing the fuel’s environmental impacts. Just like when a homeowner heats their home with a fireplace, smoke is released from the burning wood, and goes up the chimney, the combustion of coal to produce electricity has similar results. Emissions from coal can include:
- Oxides of sulfur and nitrogen — commonly called NOX and SOX,
- Carbon monoxide,
- Particulate matter (PM2.5 and PM10),
- Trace heavy metals, like mercury and selenium,
- Carbon dioxide,
- Water vapor, and
- Nitrous oxide.
Pollutants and GHGs are both heavily regulated at state and federal levels and must be monitored and limited by the companies that produce electricity. There are various compendiums of information on these technologies on the DOE, EPA, and National Energy Technology Laboratories websites.
There are also a variety of clean coal technologies and methods of combustion designed to capture pollutants and reduce emissions during and after combustion. A few of these include carbon capture utilization and storage — also called CCUS, low NOX boilers, flue-gas desulfurization, selective catalytic reduction, chemical/gas/wet/dry scrubbers, gasification, and others. However, installing these emissions reductions technologies to coal-fueled generation plants can add many millions of dollars to the cost of a plant and make the electricity produced by the plant more expensive and relatively less competitive with other generation options.
Coal use for energy production is also subject to a host of strict environmental regulations, such as the Cross State Air Pollution Rule, the Mercury and Air Toxics Standard, New Source Review, the New Source Performance Standards implemented under the authority of Section 111 of the Clean Air Act, the Affordable Clean Energy Rule and others. It is not possible to fully cover the breadth of these regulations in this paper. But, it is possible to note that the creation of these and other regulations have, regardless of market pressures or public opinion, effectively made it impossible to build any new coal-fired power plant in the U.S.