Data center growth threatens air quality and progress toward cleaner energy grid

Despite the rapid growth of renewable energy usage in recent years, the even-more-explosive growth of data centers is delaying the transition to a cleaner grid in ways that could harm the air we breathe. That’s according to new research released for Earth Day on Wednesday by Frontier Group, Environment America Research & Policy Center and U.S. PIRG Education Fund.

“It’s great that renewable energy is growing rapidly, but we also need to be transitioning away from dirty energy sources. We can't afford to lose ground on that front,” said Johanna Neumann, senior director of the Campaign for 100% Renewable Energy at Environment America Research & Policy Center. “Pollution from fossil fuels harms our kids’ lungs and dangerously heats up our planet. We need to get our priorities straight. A healthy, safe environment is essential for a good quality of life.”

The research, building on new government data, tracks a dramatic slowdown in the previously accelerating pace of coal plant retirements as utilities respond to rising electricity demand from data centers and other sources. Compared to 2022, when the country was retiring power plants at a pace that would lead to a coal-free grid by 2040, the current pace of plant retirements would keep some of our dirtiest ones online until 2065. Power generation from coal-fired power plants increased by 13% in 2025 as U.S. electricity generation hit an all-time record.

• One of the research papers, Energy Transition at Risk, uses data from the Energy Information Administration to document both the dramatic slowdown in retiring America’s dirtiest power plants and the resurgence of new proposals for gas-powered plants.
• The other research paper, Fossil fuel plants are staying online longer. That means dirtier air, uses U.S. Environmental Protection Agency data to quantify the amount of air pollution – sulfur dioxide, nitrogen oxides and mercury – produced by many of the fossil fuel power plants whose lifetimes are being extended.

The authors recommend that to reduce the environmental and public health harms of increased electricity demand from data centers and other sources, policy makers should increase energy efficiency, ease barriers to clean energy, and continue to phase out dirty power plants.

“We’ll all suffer if we rush to build new, polluting gas plants for uncertain data center demand,” said U.S. PIRG Education Fund Energy and Utilities Program Director Abe Scarr. “Instead, policy makers should prioritize no-regrets strategies like energy efficiency and renewable energy.”

The new analysis follows Frontier Group’s analysis of delayed fossil fuel power plant retirements in its January 2025 report, “Big Data Centers, Big Problems” and an update of that data in October 2025.

"It's absurd to power the technology of tomorrow with the dirty and dangerous energy sources of yesterday," said Quentin Good, policy analyst with Frontier Group. "Harming the environment and jeopardizing people's health is no way to build a better future."

The groups have also organized a petition as part of broader efforts advocating for data centers to run on 100% renewable energy, follow efficiency standards and operate in ways that reduce load stress on the grid.

Environment America Research & Policy Center, a 501(c)(3) organization, conducts research, policy analysis and public education. We illuminate the problems facing our natural world, advance solutions, and inspire intelligent debate about how to put our country and our planet on a greener, healthier path.

U.S. PIRG Education Fund, a 501(c)(3) organization, conducts research, policy analysis and public education projects. We spotlight the problems that affect consumers’ health, safety and well-being, advance practical solutions, and promote dialogue about how to elevate the quality of our lives over the quantity of “stuff” we consume.

Frontier Group provides information and ideas to build a healthier, more sustainable America.

U.S. PIRG Education Fund, Environment America Research & Policy Center, and Frontier Group are part of The Public Interest Network, which operates and supports organizations committed to a shared vision of a better world and a strategic approach to social change.