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How 2023 marked a renewed push for public power.

Voters in Maine were confronted with an unusual decision when they went to the polls this November. Question three on the ballot asked Mainers if they wanted to eliminate the two private utilities that delivered electricity to 97% of the state. A new, nonprofit utility called Pine Tree Power would take over the service, and it would be overseen by a publicly-elected board.
Though the proposal may sound radical, it’s not unheard of. Since the dawn of the electric grid, communities have periodically decided to municipalize their utilities. The city of Sacramento, California, took over PG&E’s local electric distribution franchise in 1946. Winter Park, Florida, took over electric service from a company called Progress Energy in 2005. But a takeover at the state level has only been attempted by Nebraska, where the entire state’s electric service went public in the 1940s and has remained that way ever since.
Unlike in Nebraska, the campaign in Maine failed. Seventy percent of voters said “no” to question three. But the ballot measure wasn’t a one-off. This year marked a renewed push for public power that’s growing around the country in light of the challenges of tackling climate change.
Investor-owned utilities have used their vast financial resources and political influence to delay and block the transition off of fossil fuels, in ways large and small, for decades. Activists, tired of trying to work within that system, are turning their attention to what they see as the more systemic root cause — the perverse incentives created by having utilities that need to turn a profit.
Americans often refer to their electricity or gas providers as “public utilities.” But only about 15% of the population is served by a government-owned, customer-owned, or member-owned electric utility. The other 85% are beholden to private companies that were granted monopolies to sell electricity decades ago.
What started as a smattering of independent campaigns to change that ratio started to coalesce into a nationally coordinated movement this year. A few weeks before the vote on the ballot measure, some 70 delegates from about 40 grassroots climate groups from around the country convened for a workshop at the Press Hotel in Portland, Maine. For three days, they exchanged notes and strategies for how to get public power on the agenda in their own cities and states, and reform public utilities in places that already had them. By the end, they had cemented a more energized, organized coalition.
The guiding theory behind the push for public power is that public utilities don’t need to generate returns for shareholders, theoretically enabling them to make investments guided by other priorities, like reducing emissions — and charge customers less in the process.
“We’ve seen time and time again that the market is not going to correct this,” Greg Woodring, a workshop participant from Ann Arbor, Michigan, told me. “Public power gives us the ability to choose where our energy is coming from, the ability to directly make that change without having to ask or plead or beg or incentivize a corporate entity that, at the end of the day, is only making a decision based on what’s going to make the most profit possible.”
But public power is divisive in the larger climate movement. While not necessarily ideologically opposed, critics are concerned about wasting time and money. Private utilities don’t go without a fight, and communities can get bogged down in legal battles for years. The city of Boulder, Colorado, famously tried to wrest control over its electric service from the utility Xcel for a decade, and gave up.
In Maine, the Conservation Law Foundation, a prominent environmental group, warned that the cost of a transition to public power was too uncertain, that it could mire the state in litigation, and that having a publicly-elected board could subject critical energy decisions to “partisan political maneuvering.” Instead, the group made a case for strengthening laws and regulations. However, it also conceded that if the utilities don’t meet metrics of affordability and sustainability they should face stiffer fines, or even lose their ability to operate in the state.
Defenders of investor-owned utilities argue that they have advantages over nonprofits when it comes to building the clean grid of the future. “The investor-owned business model enables companies to raise and deploy massive amounts of capital in an efficient and cost-effective manner, and their purchasing power helps to minimize costs to customers,” said Sarah Durdaller, a spokesperson for the Edison Electric Institute, a trade group for private electric utilities. She told me that the organization’s members’ “commitment to delivering resilient clean energy to our customers has never been stronger, and our focus on affordability has never been more important.”
The Maine campaign was not the first time a shift to publicly-owned utilities has been pitched as a climate strategy. One of the main motivations for Boulder’s effort, which started in 2010, was Xcel’s unwillingness to help the city meet its climate goals. But the increased momentum behind public power in 2023 signaled a new direction for climate activism more broadly, which had seemed to stagnate after the rise and fall of the youth-led Sunrise Movement and the election of Joe Biden.
“This is a site where we can practice democracy,” Isaac Sevier, one of the workshop organizers, told me. “I think that’s something that energizes people, it gives them more hope, it gives them something to be a part of and fight for and struggle for in a time when so many people are turning away.”
The workshop in Maine was convened by a handful of national organizations, including the Climate and Community Project, a progressive think tank, Lead Locally, a group that works to elect progressive candidates, and the Democratic Socialists of America’s Green New Deal Campaign Commission.
The DSA has been a major force behind the recent surge in interest in public power. At the start of this year, it kicked off a new campaign called “Building for Power” focused on trying to strengthen public institutions at the local level. In addition to public power, DSA is advocating for green public housing and transit, and improved public spaces.
“We want to rebuild, and in some cases, build anew, public sector capacity,” Matt Haugen, one of the organizers of the workshop, told me. “Through decades of neoliberalism, the public sector has been hollowed out in the U.S., and we’re seeing in all these areas that it’s clear the private sector just cannot meet these human needs.”
Many of the participants at the workshop were DSA members, but there were also local organizers affiliated with national environmental organizations, like 350 and the Sierra Club, and others from smaller, grassroots groups. There was a freshman in college, a seasoned activist in his 80s, and many ages represented in between. While almost everyone there was from a left-leaning city, they hailed from every corner of the country, including California, Montana, Michigan, Tennessee, Puerto Rico, and Washington, D.C.
Some, like Woodring of Ann Arbor, were from cities that were already in the early stages of considering a public power takeover. His group had convinced the city council to complete a feasibility study on municipalization. Others, like Marta Meengs, from Missoula, Montana, were trying to figure out how to win smaller battles, like the right to have community-owned solar farms. Others wanted to reform existing public power agencies, like Amy Kelly from Tennessee, where the federally-owned Tennessee Valley Authority runs the grid — but is investing heavily in natural gas, and offers few avenues for civic engagement.
One such group had already seen some success. The New York chapter of the DSA passed the Build Public Renewables Act earlier this year after four years of campaigning. The law directs the New York Power Authority, an existing state-owned power provider, to shut down all of its fossil fuel plants by the end of 2031, and expands its mandate to include building renewable energy projects. Most residential customers in New York are actually served by private utilities, but proponents saw the law as a way to get more clean energy built, faster, and with high labor and equity standards.
The Inflation Reduction Act, the climate law signed by President Biden last year, is one reason the tides turned for the New York campaign. It enabled government agencies and nonprofits to take advantage of tax credits for renewable energy projects for the first time, improving the economics of public power.
“It really opens up a huge amount of additional space for public power to be a part of the answer,” Johanna Bozuwa, executive director of the Climate and Community Project, told me.
Though few of the participants had ever met or even heard of each others’ campaigns, the stories that led them to advocate for public power shared a number of common themes: Worsening power outages due to extreme weather. Alarm over the insufficient pace of emission reductions. Outrageously high bills. But perhaps most of all, frustration with constantly coming up against utilities wielding money and influence to fight clean energy.
Woodring, of Ann Arbor, cited a 2022 analysis that found that more than 90% of sitting legislators in Michigan at the time took money from groups and individuals affiliated with DTE, the biggest utility in the state. The company was also tied to more than $200,000 in donations to Governor Gretchen Whitmer, who’s responsible for appointing the state’s utility regulators. As a result, according to the workshop participants from Michigan, the company has been able to restrict the growth of residential solar, which would eat into its profits.
Mikal Goodman, a 23-year-old city councilmember from Pontiac, Michigan, told me his interest in public power stemmed from DTE’s high rates and failure to invest in modernizing its transmission system. Some of its poles and wires dated back to before World War II, he said. Last winter, storms knocked out power to hundreds of thousands of households in southeast Michigan, leaving some families in the dark for over a week. But the day after one especially bad storm in February that left 450,000 people without power, DTE’s CEO Gerardo Norcia bragged to Wall Street analysts about the company’s “strong financial results” due to budget cuts and delayed maintenance.
In Pontiac, Goodman said, outages are life-threatening. He described the city as a donut hole — a poor, majority minority community surrounded by much wealthier, whiter towns. Most Pontiac residents don’t have the resources to run backup generators, replace rotting food, or flee to hotels if they need to, like many of their well-off neighbors, he said.
The idea that energy is a human right, and should not be treated as a commodity, came up repeatedly at the workshop. Many of the participants were drawn to public power by the desire to see an energy transition that benefits everyone, not just those who can afford clean energy.
Sevier, who has done a lot of work related to decarbonizing buildings, was frustrated that other advocates in the field were ignoring the growing energy affordability crisis. One in six households are behind on their utility bills, according to the National Energy Assistance Directors Association, and gas and electric utilities are increasingly disconnecting customers that are in arrears. A January report from Bailout Watch, a nonprofit watchdog of fossil fuel companies, estimated that the 12 utilities that perpetrated the vast majority of shutoffs between 2020 and the fall of 2022 could have forgiven the debt with just 1% of their spending on shareholder dividends.
“If we require that everything in your life become electric, but at the same time, we don’t transform a system that guarantees that everyone actually can have electricity,” Sevier told me, “then I ask, who are we building this ‘electrify everything’ system for?”
Other advocates questioned a system where the public is often forced to pay for a company’s mistakes, but which the public has no say over. Travis Gibrael, an organizer with a group called Reclaim Our Power in northern California, which is working on a public takeover of PG&E, described the hypocrisy of the state’s relationship with the company. Governor Gavin Newsom’s administration helped the company emerge from bankruptcy after it was found responsible for wildfires that destroyed whole towns and killed more than 100 people. Now the company is raising rates by 13% to pay for wildfire prevention measures like burying power lines.
“They burn down the state, they kill a bunch of people. And yet all of those liabilities are just put on us, including the people who lost family members,” Gibrael told me. “It’s like, we’re already paying for the cost of the system and all the crises that are coming from it. So for us to just own it, because we’re already paying for it, makes sense.”
Reclaim Our Power has allies in the city government of San Francisco, which is in the early stages of trying to purchase the local electric grid from PG&E.
In some ways, Maine seemed to be an ideal testing ground for such sweeping reforms. Central Maine Power and Versant, the two private electric companies in Maine that would have been ousted, are consistently rated the worst for customer satisfaction in the Northeast. CMP has faced multiple investigations and fines over its billing system, customer service, and delays connecting new solar projects to the grid. Mainers additionally hate the company due to a controversial power line it is building to deliver hydropower from Canada into the U.S.
Advocates also appealed to nationalist views by highlighting the fact that both companies have “foreign owners,” and that they are funneling ratepayer dollars out of the country rather than back into Maine’s communities. (CMP is owned by Iberdrola, a Spanish company. Versant is owned by Enmax, a Canadian company owned by the city of Calgary.)
Public power advocates attributed their loss largely to the nearly $40 million the incumbent utilities spent fighting the campaign. “They outspent us 37 to one,” Lucy Hochschartner, the deputy campaign manager for Pine Tree Power, told me. “We were persuading people one by one, as they were getting absolutely inundated by messaging on the television, in their mailbox, on the radio, over digital.”
But she also said the campaign was successful in that it got a lot more people talking about the issue — it made national headlines for weeks — which could make it easier for future campaigns.
Reflecting on the loss, John Qua, a campaign manager at Lead Locally, told me it showed that running a ballot initiative is probably one of the most difficult ways to win public power. Another path is to try and win an electoral majority to enact legislation. “While it takes longer, you can cement a stronger, usually progressive majority in support,” he said.
Workshop attendees were clear-eyed about the fact that public ownership would not, in itself, be a silver bullet. They were quick to acknowledge the shortcomings of many existing public institutions, and that a publicly-owned utility will only be as strong as public participation in elections and decision making — a tall order when so few people today even understand the basics about where their energy comes from. Grace Brown, a researcher at the University of Glasgow in Scotland who studies public power movements, said it’s a much harder proposition in the U.S. than in Europe, where people are used to relying on the government for services, and socialism isn’t such a dirty word.
“That’s not just about winning votes, it’s about changing the mindset of this whole country,” she told me. “It’s trying to change these huge ideological ideas of how this country understands what the state should be and what the government should do.”
Public power isn’t the only idea out there for breaking the inertia and corporate capture of the energy system. This year, Colorado, Connecticut, and Maine passed laws that will prevent utilities from charging ratepayers for their lobbying efforts. Several states are experimenting with new, performance-based regulations, whereby utilities’ compensation is tied to specific goals, including emission reductions.
There’s also evidence that the existing channels for democratic engagement with the energy system aren’t totally broken. California and Michigan both recently made big strides on the climate and equity issues that public power advocates care about. This summer, the Golden State passed a law requiring utilities to design progressive rates tied to customers’ incomes. Michigan passed a law requiring utilities to use 100% clean energy by 2040.
The revitalized push for public power is about more than clean energy. To proponents, it’s about shaping this new, green energy system in a way that benefits a wider public. Whether or not they see more victories, the questions they are raising about who decides when and how we transition to this hypothetical clean energy future are already infiltrating the wider climate discussion. And as past public power movements, like the one in Boulder, have shown, even when the campaigns fail, the threat they pose to utilities is usually enough to get the companies to change their approach.
If there’s one thing I took away from the workshop, it’s that the movement is just getting started. Expect to see more high-profile campaigns — perhaps in San Francisco or Ann Arbor — in the coming years.
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Generate Capital, CalSTRS, and the Rhodium Group have teamed up on a new Transition Acceleration Framework to measure and assess emissions impacts.
The most common way to judge whether a company or project is helping to tackle climate change is to measure emissions. Has the company reduced its carbon footprint? Will the project add fewer greenhouse gas emissions to the atmosphere than alternatives?
It’s a useful metric, but a limited one. One company might be doing more to advance the energy transition than another — by investing in an expensive, early-stage solution such as geothermal power, for example — but a comparison of their carbon footprints won’t necessarily show it. At the project level, a solar farm in Mississippi, where solar deployment has lagged, will do more to decarbonize the U.S. power grid than one of equal size in California, even though both projects emit zero carbon.
This presents a challenge for climate-minded investors like Jonah Goldman, the chief strategy officer of Generate Capital, who are trying to figure out where their dollars can make the biggest difference. To solve it, Goldman worked with colleagues at the California State Teachers Retirement System, which backs Generate’s investments, and a team at the Rhodium Group to develop a new way for investors to assess where to put their money.
“The question that most of the frameworks out there ask is, what are your carbon emissions today, and can your carbon emissions be lowered?” Goldman told me. “The Transition Acceleration Framework asks, how can you apply capital that has the best chance of getting to decarbonization over a reasonable time frame?
“It sounds like a similar question. It sounds like semantics. But it’s actually quite different,” he said.
At a high level, the Transition Acceleration Framework measures how much additional decarbonization a given investment can deliver beyond what would likely have occurred anyway. It can also be used to evaluate policy interventions and procurement decisions, such as where to get power for a data center. The Rhodium Group published a white paper describing the methodology on Thursday, as well as an accompanying report using it to evaluate options for powering data centers in the U.S.
The Transition Acceleration Framework has three components: transition potential, transition efficiency, and acceleration factor.
Transition potential is “the size of the emissions-reduction opportunity,” the white paper says — it measures the gap between the current trajectory for a given technology and its potential deployment in a deeply decarbonized world. Some of the solutions with the highest transition potential scores, per Rhodium’s analysis, include light duty electric vehicles and utility-scale solar.
Transition efficiency measures how effective a dollar spent on that technology can be at closing the gap, based on an estimate of the total capital expenditure required to realize the potential. There, more nascent solutions like low-carbon cement and geothermal power score higher than EVs and solar.
Rhodium combines these two complementary metrics into a single “technology factor,” a score on a scale from one to ten that can help identify the highest-leverage sectors to invest in. (The project is similar in spirit to Heatmap’s Decarbonize Your Life series, in which we tried to determine the highest-leverage actions a given individual could take to cut emissions. If you missed it, check it out.)
While the transition potential and efficiency metrics provide a high-level view into how transformative different types of investments can be, the third component of the framework — the acceleration factor — helps distinguish between specific projects.
This starts with an assessment of five “acceleration attributes” — cost reduction, capital availability, new markets, infrastructure and supply chains, and political economy — that represent different mechanisms by which a single investment can help move an entire technology category forward.
For cost reduction, for example, an investor might ask how likely it is that the project will reduce the cost of future deployments through learning by doing or economies of scale. If it’s a first-of-a-kind project, the answer is likely yes. For capital availability, they might look at whether the investment will de-risk the technology. Goldman praised Amazon’s early investment in Rivian delivery vans — not just because it took gas-powered Amazon vans off the road, but because it also spurred other automakers and major shippers such as Walmart and GM to follow suit.
“While the Amazon-Rivian deal wasn’t 100% responsible for it, it certainly was a huge signal to the market that there was safety in solving this last mile delivery problem,” he said.
The Rhodium report outlines a method investors can use to score and weight the various attributes and combine them with the technology factor score to reach a final “acceleration factor” score.
In an accompanying report, Rhodium researchers used the framework to compare a number of different options for powering data centers in the U.S. It’s a high-level assessment — i.e. it doesn’t consider project-specific acceleration attributes — but it provides a rough hierarchy of the arrangements that accelerate the energy transition the most against those that do the most harm. At the top of the list is a grid-connected data center that signs a power purchase agreement with a clean, firm generator, such as a nuclear or geothermal plant. At the bottom, with a negative score indicating it would actually hinder progress relative to a regular grid connection, is an off-grid data center powered entirely by natural gas.
Of course, hyperscalers prioritizing speed to power are unlikely to wait around for a nuclear plant to get built. But there are plenty of options between that and behind the meter gas. An off-grid data center that builds enough renewables and batteries for 95% of its electricity needs and relies on gas backup scores higher than a grid-connected project that buys spot market renewable energy certificates.
“Different data center power configurations can have a meaningfully different impact on the transition, even if you’re looking at things that might on the surface seem relatively similar,” Michael Delgado, a partner at Rhodium, told me.
For now, the Transition Acceleration Framework is just that — a framework. Rhodium is piloting it with Generate and CalSTRS, as well as some additional partners, conducting bespoke assessments or their portfolios and projects. The hope is that it could eventually inform not just individual investment decisions or portfolio analyses but regulations and policy packages.
“This is an open method that we’re trying to put out there and get feedback on from the investment and philanthropic and policy world,” Delgado said.
The question is whether he still has a choice.
The United States has resumed bombing Iran, the U.S. military’s regional command announced on Wednesday. The United States also bombed more than 80 sites on Tuesday, including radar and air defense facilities, but the new set of targets is more expansive.
President Trump declared on Wednesday that the ceasefire between the two countries is dead. Yet he also suggested that an extended war isn’t on the table. “We’re not looking for long term,” he said at the NATO Summit in Turkey. “Anything that happens is going to be over very quickly … and will only make it safer, including for oil.”
Such a statement surely reflects the president’s awareness that his war isn’t very popular among Americans. But does he have any leverage anymore over how long the war lasts? When Trump okayed the interim Iran ceasefire in June, he said that Iran would not toll oil and gas tankers passing through the Strait of Hormuz. Since then, Iran and Oman have started setting up the infrastructure to do just that. That discrepancy may have been the ceasefire’s doom: The truce broke down after Iran fired missiles at oil and natural gas tankers that were allegedly not using its approved route through the strait. (Iran has said that its preferred route through the waterway is the “only safe passage.”)
American officials have said that restoring freedom of navigation through the Strait of Hormuz is one of their goals in ending — and now, resuming — the war. But the strait was open to all before the war began; Iran only shuttered it after the United States and Israel began bombing in February. Yet now that Iran has learned how easily it can close the strait and keep it closed, it has a new weapon to wield over the American and European economies.
And what of the country’s nuclear program? Back in March, it allegedly didn’t play into the calculus, partly because President Trump claimed the U.S. had destroyed the program in 2025. Instead, Secretary of State Marco Rubio said that the president had no choice but to enter the new conflict because Israel was already going to bomb Iran, and since the Islamic Republic would respond by targeting American bases in the Middle East, the United States might as well strike first. A day later, President Trump changed the story, saying that Iran was already planning to bomb U.S. military bases, which forced pre-emptive action on America and Israel’s part.
Yet by April 1, the president had justified the war to the American people by citing Iran’s nuclear program more than 20 times. “For years, everyone has said that Iran cannot have nuclear weapons. But in the end, those are just words, if you’re not willing to take action when the time comes,” he said. The new conflict had obliterated the country’s navy, defense industrial base, and ability to produce missiles, he said. Yet Iran — partly thanks to its small, cheap drones — was able to keep the strait closed for another two months.
What does all of this mean for energy and decarbonization? More expensive fossil fuels. The global crude benchmark Brent surged to $80 a barrel today, while West Texas Intermediate surpassed $74, bringing both to roughly the same level as when the June ceasefire was first announced. Researchers at Brown University estimate that Americans have paid $60 billion — or roughly $500 per household — more for gasoline and diesel than they would have had the conflict never happened.
If this stage of the war doesn’t go “long term,” as Trump hopes, then at least the world will have a little more oil than anticipated to work with, as stockpiles have risen in recent days. But a new and extended phase of the war threatens a return to the prices seen earlier in the spring — or prices that go even higher, should China decline to tap its reserves this time. One potential early pain point is diesel, which is already expensive because of Ukraine’s strikes on Russian refineries. Costlier fuel will keep encouraging more EV sales in Europe, Asia, and even the United States; high diesel prices in particular will provide a tailwind to the shockingly rapid electrification of China’s trucking sector.
Of course, the war will bring much more besides — more squandered time, more military spending, more human misery. It is the first that Trump might regret most. A conflict the White House joined without much public debate — and once forecast would last “four to six weeks” — now looks likely to eat much of his second term.
Pollution from peaker plants combined with heat and smoke can push summer air quality into the danger zone.
If you ever have to pick a day to stay inside, pick July 5. In cities across the United States, the Fourth of July’s pyrotechnic revelries make the wee hours after Independence Day consistently one of the worst of the year for air quality. Just look at Washington, D.C., which briefly held the distinction of having the world’s most polluted air this past Sunday morning following one of the largest firework displays in history.
But if you have to pick a second day to stay inside, shoot for one during the second half of July, which is the hottest period of the year in the United States. For one thing, it’s just plain miserable out. For another, the country’s 1,000 or so peaking power plants, or “peakers,” are more likely to be operating to meet the energy demands of heavy air-conditioning use, emitting disproportionately high levels of pollution for the electricity they generate.
Peakers are the backup power sources operators run only when demand is at its highest, such as during a heat wave. Peakers are also “probably the dirtiest and most expensive energy on the grid,” Abbe Ramanan, who leads the Phase Out Peakers project at the nonprofit Clean Energy Group, told me. “They tend to burn dirtier fuels, such as oil, and typically have older and less efficient emissions control systems.”
Some 63 million Americans live within a three-mile radius of a peaker, according to a 2023 Clean Energy Group report, where they face health conditions including “significant … increases in estimated rates of hospitalization for asthma, acute respiratory infection, and chronic obstructive pulmonary disease,” all conditions associated with proximity to fossil fuel-fired plants. On top of that, historic redlining practices mean two-thirds of peakers are located in communities with a higher percentage of low-income households than the national average, according to the group’s reporting. And yet peakers also provide life-saving power and AC when a blackout could mean death, such as during last week’s heat wave on the East Coast, making them simultaneously a menace and necessity to maintaining public health, at least with our current grid.
What exactly is peaker plant pollution? How does it appear in the Air Quality Index you might see on your phone? And how do local regulators consider pollution when issuing air quality forecasts? I set out to get answers.
To understand peaker plant pollution, let’s start with a refresher on how air quality alerts work.
The AQI scale runs from 0 to 500 and reflects the local concentrations of five major pollutants: particulate matter, ozone, carbon monoxide, sulfur dioxide, and nitrogen dioxide. Each pollutant has an Environmental Protection Agency-regulated benchmark for what is safe (many of which are set at levels clean air advocates argue are too lax). As concentrations increase, the overall AQI rises to warn first “sensitive groups” and then the general public when to take precautions, such as limiting outdoor activity or wearing a mask. (To learn more about the AQI scale, read my colleague Emily Pontecorvo’s explainer here.)
As do all fossil fuel power plants, peakers release planet-warming carbon dioxide as a byproduct of combustion, along with nitrogen oxides, particulate matter, volatile organic compounds, and other trace toxins that aren’t captured in the AQI, such as heavy metals. Oil and coal-fired power plants also release sulfur dioxide, which creates acid rain; natural gas-fired plants, on the other hand, emit comparatively little.
While NOx is an irritant in its own right, it is, more significantly, a key ingredient in the chemical reaction that creates ozone. When NOx mixes with volatile organic compounds — found in vehicle exhaust, personal care products, and yes, also power plant emissions — on a warm, sunny day, the chemical reaction creates ground-level ozone, which is corrosive enough to scar lung tissue with repeated, prolonged exposure. An expert once helpfully likened it to me as “sunburn on your lungs.” Health researchers have determined that, globally, ozone (also known as smog) causes a million premature deaths every year.
Yes, although it’s not an easy or neat measurement.
Peaker plants are used to rapidly supply electricity to the grid when demand exceeds the baseload capacity. As a result, they run infrequently — only about 5% of the year, or 464 hours per plant, in 2022, per Clean Energy Group’s analysis of 2022 EPA data. Using a stricter definition of peakers, the Government Accountability Office found that the plants represent nearly a fifth of the nation’s potential generating capacity but produce only about a 30th of its overall electricity, mostly due to the time they spend sitting idle.
Power plants use a number of emission control systems to limit emissions of various pollutants. But the EPA has much looser requirements for low-operating peakers, which “may not have effective, if any, emissions control technology,” the GAO writes. When operational, peakers emit an estimated 60 million tons of CO2 per year, with a median NOx emission rate about 6.1 times greater per unit of electricity generated by natural gas-fueled peakers compared to non-peaker gas plants.
“One really big issue with peakers is the emissions control systems are not operating during times when the plant is starting up or shutting down, which means that emissions are just unabated during those times,” Ramanan told me. “And because those plants tend to operate in short bursts, such as during a heat wave, they will start up and shut down more frequently.” Even up to a day beforehand, when the plant is running its test cycle, it might be emitting pollutants even while not actually providing any power.
One 2017 study by University of Wisconsin–Madison researchers found that across the Eastern U.S. from 2007 to 2012, total electricity generation rose by about 4% for every 1-degree Celsius (1.8-degree Fahrenheit) increase in daily summer temperature, with NOx correspondingly up 3.6% and CO2 up 3.3%. Though these numbers aren’t peaker-specific, the plants represent a disproportionate share of the rise since they’re reserved for the hottest, heaviest-load days.
Though the slower rise in NOx suggests “slightly cleaner plants … on average,” the authors write, that is “not completely unexpected, as new natural gas plants are required to have controls installed even as some peaking plants do not.” They note, however, that their data does not fully capture grandfathered-in units, since gas- and oil-fired peakers are allowed non-direct-measurement reporting.
In fact, in Maine and Connecticut, which “use more petroleum for electricity generation than most states in the U.S., primarily as peaking plants deployed on the hottest days,” NOx jumped 33% and 23% per degree Celsius, respectively. Separately, a 2016 study found that peaking plants may have accounted for up to 87% of local particulate matter in the PJM Interconnection during a July 2006 heat wave.
Peaker plant pollution is significant enough that chronic exposure in local communities has measurable health impacts. But how does it factor into summer AQI levels?
My colleague Matthew Zeitlin spoke this week with Margaret LaFarr, the New York State Department of Environmental Conservation’s director of air resources, who told him that peaker plant pollution is “one of the factors we consider” in formulating its air quality forecasts. But because the state’s agency uses modeling to predict when and where air quality will be poor, the granularity of a single peaker just isn’t there. “If we have to have specific information on the emissions, it would not be ready in time for a timely advisory,” LaFarr said.
Ramanan, whose nonprofit has diligently recorded the negative impacts of peakers, concurred that it is “difficult to pinpoint just how much peaker plants contribute to local air pollution because those sorts of studies are just very expensive to do.” Studies that look at disproportionate health impacts, on the other hand, are a little simpler to put together.
Additionally, while the AQI might rise locally near peakers during a heat wave, because of the nature of the scale, it can’t neatly distinguish why. A high ozone reading, for example, might just as easily be due to tailpipe emissions on a hot day; in the New York metro area, vehicles are responsible for an estimated 60% of the air pollution. Meteorological conditions — whether it’s sunny, a key factor in ozone formation, or which way the wind is blowing — obscure the picture. Particulate matter readings could be from a peaker, for example, but they could just as easily be from wildfire smoke.
One way air quality activists like to think about peaker pollution is as a co-occurrence — that is, a compounding pollution on top of already degraded conditions. Hot days tend to be the worst for ozone already, because of the aforementioned tailpipe pollution; peakers, activated to help with the heat-related energy load, then release more ozone-generating emissions at the worst possible time.
While a precise breakdown of the AQI might not be there for peakers, “we know the days that are more conducive to ozone formation generally tend to be those same days where people are cranking up their ACs and there is a higher demand for energy,” LaFarr said.
There is some speculation that cleaner input fuels could help reduce the worst peaker plant emissions. Generally, this is true: The 2017 study by the University of Wisconsin–Madison researchers found that from 1997 to 2015, in Texas, petroleum use in electricity generation dropped 85% and coal dropped 12%, while natural gas increased 57%. As a result, Texas had the lowest level of SO2 sensitivity of any state.
But beyond the existing fuel mixes, fuel switching is not a clean fix for peaker plants. “Burning things like hydrogen and [methane captured from waste processing facilities] don’t actually reduce the air pollution burden in any meaningful way,” Ramanan argued. “Hydrogen in particular tends to actually have extremely high levels of NOx emissions when it’s combusted.”
In Astoria, a neighborhood of New York City, activists opposed retrofitting the local oil-powered peaker plant to run on natural gas because doing so would “lock the state into relying on fossil fuels for decades, fly in the face of the state’s climate law that requires a drastic reduction in carbon emissions by mid-century and continue to pollute in an already overburdened community where many residents are immigrants and live below the poverty line,” Inside Climate News reported. At the same time, doing so would “reduce the state’s greenhouse gas emissions by more than 5 million tons through the year 2035,” per its owner, NRG Energy.
But a third way emerged: New York eventually denied NRG’s permit because it violated the state’s climate law, and the utility subsequently sold the Astoria facility to serve as the converter station for Beacon Wind, a development off the coasts of New York and Massachusetts.
While wind, new transmission, and battery storage all face enormous headwinds in the current political climate — meaning that many peaker plants targeted by activists for retirement are likely to stick around for years yet — advocates remain adamant that a playbook exists for decarbonization. “In terms of replacing one-to-one capacity, we’ve been looking at battery storage even just at peaker plant sites that can be paired with renewables or grid connected batteries,” Ramanan said, adding that “really great work is also being done in terms of virtual power plants and demand reduction — because it’s not just about reducing peak capacity, it’s also reducing the peak overall.”
That raises a final, particularly thorny question: Is air pollution from peaker plants “worth it” if it means being able to run AC?
A 2018 follow-up study by the same team of researchers at the University of Wisconsin–Madison explored a similar question. They found that climate change alone would increase summer mortality related to the smallest airborne particulate pollution by more than 13,500 deaths, and ozone-related mortality by more than 3,500 deaths in a mid-century scenario. AC-driven power sector emissions — full-fleet numbers, albeit disproportionately including peakers — would, on top of that, account for 654 PM 2.5 deaths and 315 ozone deaths, a nearly 5% and 9% increase, respectively, over climate impacts alone.
Researchers credit access to air conditioning in the United States with a 75% decline in deaths, and modeling exercises frequently show that a blackout during a heat wave could realistically result in hundreds of thousands of people needing medical attention. But clean air advocates also point to examples like Astoria, where the denial of a permit to retrofit a peaker plant for slightly better fossil fuels resulted in the grounds being used for a renewable energy source instead.
It’s certainly not an easily replicable process given the current political and economic climate, but it also perhaps suggests a false dichotomy of peakers vs. AC. Affordable power and livable spaces are just two among a host of community needs energy and public health officials must keep in mind.
“It’s not enough to just replace the existing system with renewables and battery storage and have fewer emissions,” Ramanan said. “It also has to be equitable, because otherwise we’re just going to replicate the same issues we’re having now in different ways.”