Fisherman near power plant and dock on Lake Superior in Ashland WI

Mercury pollution regulations are under threat—how it could play out

 January 14, 2019 

As the end of 2018 draws nearer, headlines are once again starting to crop up about the U.S. Environmental Protection Agency (EPA)—under the current White House administration—considering significant rollbacks of the Mercury and Air Toxics Standards (MATS) regulations, possibly even setting the stage for a full repeal.

This could be an unmitigated tragedy. In its short life—announced in 2011, implemented in 2012, and compliance required by 2015/2016—MATS has emerged as one of the single most-effective regulations in American history for protecting human health and the environment, especially from the ravages of mercury exposure.

Over the past half century, myriad regulations have been heralded for their role drastically reducing the harmful effects from known toxic pollutants: removing lead from gasoline and paint, removing arsenic from drinking water. MATS is of a similar echelon when it comes to drastically reducing mercury pollution from coal-fired power plants.

The resounding success of MATS: 86% mercury emissions reductions

An analysis by the Center for American Progress (CAP) found a 65% nationwide reduction in annual power plant mercury emissions during the three-year period 2014–2017. Since 2011, CAP finds an 82% drop.

WattTime also crunched the numbers for eight states throughout the Great Lakes region across a similar time period (2014–2018) and found even more striking results: an 86% reduction in mercury emissions. Perhaps just as importantly, these significant emissions reductions were not via a gradual decline over those years. Mercury emissions essentially fell off a cliff. Pre-MATS and post-MATS mercury emissions were night and day. In other words, the regulations were highly effective.

A victory for human health and the environment is at risk

Mercury’s profoundly negative health effects are well-known: it ranks on the World Health Organization’s top 10 list of chemicals that pose a major public health concern. It’s the economic tally of those health effects—and their subsequent impact on the U.S. economy—partly at the heart of the MATS controversy.

Environmental regulations like MATS are generally evaluated on the cost for industry to comply with the regulation vs. the dollar-value benefit (e.g., healthcare costs, economic productivity) the regulation delivers. Mercury emissions-reducing technology is not cheap. It costs the electric utility industry an estimated $9.6 billion per year to comply, prompting the New York Times to label it “the most expensive clean air regulation ever put forth by the federal government.” Some proponents of MATS argue that the cost of compliance is actually far less than the $9.6 billion estimate. But regardless, MATS compliance is relatively expensive.

On the other side of the coin is the economic value of the human health and environmental benefits MATS delivers. Original federal estimates put the direct mercury-reduction benefits at less than $10 million annually. Such meager numbers have generally been widely debunked. Harvard University’s School of Public Health notes that “mercury-related benefits from MATS are orders of magnitude larger than previously estimated,” on the scale of several billion dollars per year. Meanwhile, both the original federal estimates and subsequent third-party review estimate indirect co-benefits at a whopping $24–$80 billion annually, since mercury-related MATS-compliance technologies also reduce other harmful pollutants such as sulfur dioxide and nitrogen oxide.

If MATS is significantly weakened or repealed, mercury emissions are at risk of jumping up

Whether the true cost to run MATS compliance technology is $9.6 billion or something else, the fact is there remains a cost associated with the tech. Part of that expense is sunk upfront capital cost to install the technologies in the first place and part is ongoing operational costs to keep MATS-compliance technologies running.

Many utilities and other stakeholders have argued that the electricity sector broadly has already invested in these technologies, so there’s no sense going back to a pre-MATS world. To a degree, that’s true. But undoubtedly, coal-fired generators will have economic incentives to turn off their mercury emissions-reducing tech in a bid to reduce costs and stay more price-competitive.

If they do, the grid’s mercury emissions could rocket back up closer to their pre-MATS levels. For our part, WattTime will be watching. With our unique algorithms and near-real-time insights into grid emissions, we’ll be one of the first to know.

Possible pathways in a MATS (or post-MATS) future

There’s of course a big fork in the road looming just ahead, obscured by the fog of EPA uncertainty: either MATS continues in existence largely resembling its current form or MATS shrinks to a shadow of its former self, possibly disappearing entirely. If the latter—and legal challenges to its dissolution not withstanding—all is not necessarily lost.

WattTime’s Automated Emissions Reduction (AER) technology could potentially step in to do what an eviscerated MATS couldn’t. AER focuses in particular on marginal generators, those power plants “on the margin” of the dispatch curve that turn on or off in response to rising and falling electricity demand.

For customers passively using electricity, that all happens invisibly in the background of grid operations. But with smart devices controlling flexible electricity loads—thermostats, batteries, electric vehicles, electric water heaters, etc.—customers can start shifting the timing of their electricity demand to proactively turn marginal generators on or off, like a light switch for the electricity grid. And if we knew which power plants were on the margin when, we could start applying customer-driven criteria to the smart devices to effect specific outcomes, such as using more renewable energy and avoiding more fossil-fueled energy, or reducing marginal carbon and other GHG emissions, or—in the case of MATS—avoiding those generators with higher mercury emissions.

AER is the solution that delivers on this promise. In a (hopefully hypothetical) post-MATS world, AER could prove a powerful tool for avoiding mercury emissions in two critical ways:

First, direct implementation of AER on smart devices could shift electricity demand to avoid marginal generators with high mercury emissions rates and use more electricity during times when marginal generators are mercury emissions-free. According to WattTime analysis, attacking marginal mercury emissions in this way could reduce annual energy-related mercury emissions in the Great Lakes region by a meaningful 16% if AER were adopted at scale.

Second, broad customer adoption of AER could provide a strong market signal for fossil-fueled power plants to keep their MATS-compliance technologies running. With the United States’ merit order dispatch stack for electricity generators, a given power plant only provides power—and, importantly, only gets paid—if it’s part of the dispatch stack. Thus there’s strong incentive to stay in the stack.

Meanwhile, AER gives customers the power to help decide who’s in or out of the stack based on criteria such as emissions. If large numbers of customers leverage AER software to avoid power plants that have higher mercury emissions, those power plants will have a good reason to keep their MATS-compliance technologies running. That outcome would help reduce mercury emissions whenever those power plants are running, and not just when they’re on the margin.

Of course, here at WattTime we’re rooting for MATS to survive. Either way, however, AER remains a compelling tool that gives customers the power to choose clean energy—and, if need be, avoid what could be a lamentable increase in mercury emissions.