Last December, the Court of Appeals for the District of Columbia Circuit ruled that the Environmental Protection Agency could enforce the so-called Mercury and Air Toxics Standards (MATS) ruling until it is able to fully address the high court's concerns; the US Supreme Court ruled 5-4 on this issue, with the deciding vote cast by Justice Antoine Scalia, who must now be replaced.
Even with that high court ruling, however, the US Energy Information Administration has said that most coal plants are either coming into compliance or they are retiring their older coal units that are too expensive to retrofit. From December 2014 until June 2016, coal-fired capacity fell from 299,000 megawatts to 276,000 megawatts. Coal-fired generation's share of total electricity generation fell from 39 percent in 2014 to 28 percent in the first four months of 2016, it adds.
Between January 2015 and April 2016, about 87,000 megawatts of coal-fired plants had installed pollution control equipment, it says. About 20,000 megawatts of coal had retired.
According to the energy agency, MATS establishes emissions limits for toxic air pollutants associated with coal combustion such as mercury, arsenic, and heavy metals. It requires all coal generators that sell power and have capacity greater than 25 megawatts to comply with specific emission limits by April 2015.
To be clear, the Supreme Court’s decision does not nullify the proposal to curb mercury emissions. It says EPA must take into account the cost of regulations at the initial stage — the one where it determines that regulation of hazardous emissions from electric power plants would be “appropriate and necessary.”
In this case, EPA says that it considered those costs but had waited until a latter stage to do so — the one where it had actually drawn up the proposed rules. At that point, EPA had estimated the cost of its proposal to be $9.6 billion a year. But it said that would produce as much as $90 billion a year in benefits.
With that, EPA set out to require cuts in mercury emissions of 90 percent in 2012, saying that the technologies to do so were available — a rule that was subsequently challenged by the state of Michigan, several coal-related groups, and Peabody Energy.
What now? The reality is that Obama administration has been blessed by the high court on a number of its regulations, which include those tied to sulfur dioxide, nitrogen oxide and carbon dioxide. The court, by-and-large, has been deferential to EPA.
And the fallout of those earlier rulings has only facilitated the retirements of older coal plants -- a trend that is likely to continue, given that there are cheaper options that release fewer emissions: natural gas.