Nearly 10 percent of today’s electricity in the United States comes from wind power. Renewable energy benefits the climate, air quality and public health by displacing emissions of greenhouse gases and air pollutants that would otherwise be produced by fossil fuel-based power plants.
A new MIT study finds that the health benefits associated with wind power could quadruple if operators prioritize reducing power from the most polluting fossil fuel-based power plants when wind power is available.
In the study published in Scientific progress, researchers analyzed hourly wind turbine activity as well as reported emissions from every fossil fuel-based power plant in the country between 2011 and 2017. They tracked emissions across the country and mapped pollutants to affected demographics. They then calculated regional air quality and associated health costs for each community.
Researchers found that in 2014, wind energy that was linked to state-level policies improved overall air quality, resulting in $2 billion in health benefits nationwide. However, only approximately 30 percent of these health benefits reach disadvantaged communities.
In addition, the team found that if the electricity industry reduced the production of the most polluting fossil fuel-based power plants, rather than the most energy-efficient plants, in times of wind power, the total health benefits could quadruple to $8.4 billion In the whole country. However, the results would have a similar demographic breakdown.
“We found that prioritizing health is a great way to maximize benefits in a widespread way in the US, which is a very positive thing. But it suggests it won’t address the differences,” said study co-author Noel Selin, a professor in the Institute for Data, Systems and Society and the Department of Earth, Atmospheric and Planetary Sciences at MIT. “To address air pollution disparities, you cannot simply focus on the electricity sector or renewables and rely on the overall benefits of air pollution addressing these real and persistent racial and ethnic disparities.” You’ll have to look at other sources of air pollution, as well as the underlying systemic factors that determine where plants are located and where people live.”
Celine’s co-authors are lead author and former MIT student Minghao Qiu PhD ’21, now at Stanford University, and Corwin Ziegler of the University of Texas at Austin.
In their new study, the team looks for patterns between periods of wind power generation and fossil fuel-based power plant activity to see how regional electricity markets adjust power plant output in response to the influx of renewable energy.
“One of the technical challenges and contributions of this work is trying to identify which are the power plants that are responding to this growing wind energy,” notes Qiu.
To do this, the researchers compared two historical datasets from 2011 to 2017: an hour-by-hour record of energy produced by wind turbines across the country and a detailed record of emissions measurements from every fossil-based power plant fuel plant in the US The data sets cover each of the seven major regional electricity markets, with each market providing power to one or more states.
“California and New York are each their own markets, while the New England market spans about seven states and the Midwest spans more,” explains Qiu. “We also cover about 95 percent of all wind power in the U.S.”
In general, they observed that in times when wind power was available, markets corrected, essentially reducing the capacity of natural gas and sub-bituminous coal-fired power plants. They noted that the plants that were rejected were likely chosen for cost-saving reasons, as some plants were cheaper to reject than others.
The team then used an advanced atmospheric chemistry model to simulate the wind patterns and chemical transport of emissions across the country and determine where and at what concentrations emissions generate fine particulate matter and ozone, two pollutants known to impair air quality. of air and people health. Finally, the researchers mapped general demographic populations across the country based on U.S. Census data and applied a standard epidemiological approach to calculate the population’s health costs resulting from their exposure to pollution.
This analysis revealed that in 2014, a common cost-savings approach to shifting fossil fuel-based energy in times of wind power resulted in $2 billion in health benefits or savings nationwide. A smaller share of these benefits went to disadvantaged groups, such as minorities and low-income communities, although this disparity varies by state.
“It’s a more complicated story than we originally thought,” says Qiu. “Certain population groups are exposed to higher levels of air pollution and that would be low-income people and racial minority groups. What we’re seeing is that wind energy development can reduce that gap in certain states, but further increase it in other states, depending on which fossil fuel plants are displaced.”
The researchers then examined how the emissions pattern and associated health benefits would change if they prioritized switching off different fossil fuel-based installations during wind power. They changed the emissions data to reflect several alternative scenarios: one in which the healthiest, most polluting power plants shut down first; and two other scenarios in which the plants producing the most sulfur dioxide and carbon dioxide, respectively, are the first to reduce their production.
They found that while each scenario increased health benefits overall, and the first scenario in particular could quadruple health benefits, the original disparity persisted: minority and low-income populations still had smaller health benefits than wealthier ones communities.
“We’ve come to the end of the road and said there’s no way we can deal with this mismatch by being smarter about deciding which plants to displace,” Selin says.
“One of the things that makes me optimistic about this field is that there is a lot more attention to environmental justice and equity issues,” Selin concludes. “Our role is to understand the strategies that are most effective in addressing these challenges.”
This work was supported in part by the US Environmental Protection Agency and the National Institutes of Health.