According to a new study, the health benefits of wind power could more than quadruple if operators reduced output from the most polluting fossil-fuel-based power plants when wind energy is available. However, disadvantaged communities would receive a smaller share of these benefits when compared to wealthier communities.
Wind power accounts for nearly 10% of current electricity generation in the United States. Renewable energy benefits the climate, air quality, and public health by replacing emissions of greenhouse gases and air pollutants produced by fossil-fuel-based power plants.
According to a new MIT study, the health benefits of wind power could more than quadruple if operators prioritized turning down output from the most polluting fossil-fuel-based power plants when wind energy is available.
Researchers examined the hourly activity of wind turbines as well as the reported emissions from every fossil-fuel-based power plant in the country between 2011 and 2017, according to the study published in Science Advances. They tracked emissions across the country and linked pollutants to affected demographic groups. They then calculated the regional air quality and the health costs associated with each community.
We found that prioritizing health is a great way to maximize benefits in a widespread way across the U.S., which is a very positive thing. But it suggests it’s not going to address disparities.
Noelle Selin
The researchers discovered that wind power associated with state-level policies improved overall air quality in 2014, resulting in $2 billion in health benefits across the country. However, only about 30% of these health benefits reached underserved communities.
The team also discovered that reducing the output of the most polluting fossil-fuel-based power plants, rather than the most cost-effective plants, during times of wind-generated power could quadruple the overall health benefits to $8.4 billion nationwide. However, the demographic breakdown would be similar.
“We found that prioritizing health is a great way to maximize benefits in a widespread way across the U.S., which is a very positive thing. But it suggests it’s not going to address disparities,” says study co-author Noelle Selin, a professor in the Institute for Data, Systems and Society and the Department of Earth, Atmospheric and Planetary Sciences at MIT.
“In order to address air pollution disparities, you can’t just focus on the electricity sector or renewables and count on the overall air pollution benefits of addressing these real and persistent racial and ethnic disparities. You’ll need to look at other air pollution sources, as well as the underlying systemic factors that determine where plants are sited and where people live.”
Selin’s co-authors are lead author and former MIT graduate student Minghao Qiu Ph.D. ’21, now at Stanford University, and Corwin Zigler at the University of Texas at Austin.
Turn-down service
The researchers looked for patterns between periods of wind power generation and the activity of fossil-fuel-based power plants in their new study to see how regional electricity markets adjusted power plant output in response to renewable energy influxes.
“One of the technical challenges, and a contribution of this work,” Qiu says, “is identifying which power plants respond to this increasing wind power.”
The researchers compared two historical datasets from 2011 to 2017: an hour-by-hour record of energy output from wind turbines across the country and a detailed record of emissions measurements from every fossil-fuel-based power plant in the United States. The datasets covered each of the seven major regional electricity markets, each of which supplied energy to one or more states.
“California and New York are each their own market,” Qiu explains, “whereas the New England market covers around seven states and the Midwest covers more. We also cover approximately 95% of all wind power in the United States.”
In general, they observed that, in times when wind power was available, markets adjusted by essentially scaling back the power output of natural gas and sub-bituminous coal-fired power plants. They noted that the plants that were turned down were likely chosen for cost-saving reasons, as certain plants were less costly to turn down than others.
The researchers then used a sophisticated atmospheric chemistry model to simulate wind patterns and the chemical transport of emissions across the country, determining where and at what concentrations the emissions produced fine particulates and ozone – two pollutants known to harm air quality and human health. Finally, the researchers used U.S. census data to map general demographic populations across the country and used a standard epidemiological approach to calculate a population’s health cost as a result of pollution exposure.
According to this analysis, a general cost-saving approach to displacing fossil-fuel-based energy in times of wind energy resulted in $2 billion in health benefits, or savings, across the country in 2014. Disadvantaged populations, such as minority and low-income communities, received a smaller share of these benefits, though this disparity varied by state.
“It’s a more complicated story than we thought,” Qiu says. “Certain population groups, such as low-income people and racial minority groups, are more vulnerable to air pollution. We believe that developing wind power will narrow the gap in some states while widening it in others, depending on which fossil-fuel plants are displaced.”
Tweaking power
The researchers then investigated how the pattern of emissions and the associated health benefits would change if they prioritized shutting down different fossil-fuel-based plants when wind-generated power was available. They modified the emissions data to reflect several alternative scenarios, including one in which the most health-damaging, polluting power plants are shut down first, and two others in which plants emitting the most sulfur dioxide and carbon dioxide are shut down first.
They discovered that, while each scenario increased overall health benefits, and the first scenario in particular could quadruple health benefits, the original disparity remained: minorities and low-income communities continued to experience lower health benefits than more affluent communities.
