Electricity and Health

How does electricity use affect human health?

A 3D icon shows a trio of data visualizations in charts and graphs.
Seven million people a year die from air pollution, and a lot of it comes from power plants. Using electricity at particular times can help.

Fossil fuel power plants cause premature death

Fossil-fueled power plants emit damaging air pollutants like sulfur dioxide, nitrogen oxides, and particulate matter. These pollutants contribute to more than 100,000 premature deaths each year in the United States, and also lasting health problems like asthma, heart disease, and stroke. Air pollution also makes people more susceptible to COVID-19.

Often, many especially dirty power plants will cluster in a particular area, causing a disproportionate burden to the nearby community. People of color are often the hardest hit. These pollution pockets also tend to occur where low-income people live.

What happens when we plug in?

Of course, power plants only operate because we all use electricity. Every time any device–from a small laptop to a powerful electric vehicle charger–draws power, at least one power plant on the local grid (the “marginal” generator) immediately ramps up to provide that energy.

But which power plant is the marginal generator in each grid? It’s always changing. And that matters, because some power plants cause much more pollution and harm than others. So, using electricity at some times and places causes more harm to people than using it at other times and places.

Using WattTime data, we can now do better

That’s why WattTime has spent years researching and developing technology to identify which power plant is marginal, when, on each grid. We turn this into a real-time estimate and a 24-hour forecast, updated every five minutes. These data enable people to reduce the pollution impact of their electricity use.

Many devices like smart thermostats and electric vehicles use the WattTime signal to automatically time their electricity use to moments that don’t cause as much harm. (We call it AER.) Other companies use these data to deliberately build new large energy-using facilities, like data centers, in places where they cause less harm. (We call that emissionality.)

If your company is not yet optimizing devices, you can also start by measuring the impacts of electricity use in devices or at your facilities.

With enough collective action to avoid using electricity at the dirtiest times and from the most harmful power plants, we can speed up the closure of the plants that are most damaging.

From emissions to health

Until now, WattTime’s data have only measured the greenhouse gas emissions that cause climate change. Now, they also measures air pollutant emissions that cause human health harm.

But our new health signal goes beyond just measuring the pollution from power plants, by factoring in what happens after it leaves the smokestack. Like electricity, air pollution itself is more harmful in certain times and places than others. For example, one ton of air pollution is more harmful if it's emitted in the middle of a crowded city where potentially thousands more people will breathe it, than if it's released out in a field far from people.

That’s why today, WattTime has begun measuring the actual human health harm caused by using electricity at different times and places. The health harm is lower at times when the responding power plants are cleaner or at least farther from population centers.

The health data is currently available for the United States, and we are beta-testing its delivery through our API. When officially released, our partners will be empowered to optimize devices to reduce health harms, climate harms, or both (our analysis has shown that in most cases co-optimizing will simultaneously achieve the majority of the reductions achieved by optimizing for each individual factor).

How does WattTime estimate health impacts?

WattTime developed a model that estimates the health damage effects of using electricity at different times of day in particular locations. This is done by first determining which power plants are likely to respond to an increase in electricity use on a local grid and how much pollution they make. How much pollution reaches nearby areas is dependent not only on what fuel is burned, but also whether pollution control filters are installed (a relatively easy step that when skipped, causes a lot of harm) and the height of the smokestack, and all of these factors are accounted for in the model. The number and distance of people that live and work downwind of the smokestack are considered to determine the number of premature deaths that are caused by the pollution coming from the responding power plants. The health damage effect changes throughout the day based on which power plants are responding to changes in usage on a local grid.