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Yale currently plans to reach zero carbon emissions by 2050, but scientists and activists say the University cannot wait to address two of its largest sources of pollution — the Central Power Plant and the Sterling Power Plant — which together accounted for 98.5 percent of the University’s greenhouse gas emissions in 2020.

According to Chair of the US Collegiate Energy Consortium Sena Sugiono ’25, Yale produced 198,000 metric tons of greenhouse gases in 2020, representing a 43 percent decrease in its emissions since 2005. Publicly-available data from the Environmental Protection Agency revealed that the University’s two power plants were responsible for 195,000 of those 198,000 metric tons of emissions. But experts and activists said that Yale has the resources and power to act now and develop renewable energy solutions. 

“Given Yale’s status as a premier research institution, I really do think Yale has the responsibility to lead by example with its own transition towards decarbonization and environmental justice,” Noah Lerner SOM ’22 wrote in an email to the News. 

In its 2021 Sustainability Progress Report, Yale announced its plans to use “emerging technologies” like deep earth geothermal heat, biomass gasification and green hydrogen processes to reduce its actual carbon emissions to zero by 2050. 

However, these projects are slated to begin in the mid-2030s.

“Using language like mid-2030s and ‘emerging technologies’ is pretty telling on how confident Yale and other industry folks are in being able to transition existing fossil fuel infrastructure into clean infrastructure,” Noah Mitchell-Ward ENV ’22 wrote in an email to the News. 

To reach carbon zero emissions, Mitchell-Ward explained, Yale is looking to use technologies that have not yet been developed. 

The Central Power Plant and Sterling Power Plant form the backbone of Yale’s power grid. Since these combined plants generate heat and power, they are “relatively” energy-efficient, according to Lerner, but still burn natural gas. 

Isabel Harrison ENV ’22 explained that “getting off natural gas is one of the biggest challenges that many institutions are facing on their climate journeys.” 

The Central and Sterling Power Plants are two of the three “large facilities” emitting greenhouse gas in New Haven, according to the EPA. The other facility is the New Haven Harbor Station. While the Station emitted 14,297 metric tons of greenhouse gas in 2020, the Central and Sterling Power Plants emitted a combined 194,958 metric tons of greenhouse gas. 

Since both power plants contribute to air pollution in New Haven, Lerner believes that the University will need to transition to more environmentally friendly sources of energy to fulfill its climate commitments. 

In 2019, New Haven produced 1,422,668 metric tons of greenhouse gas emissions. According to Pamela Torola ’18, an economics doctoral student at Yale who helped New Haven conduct a greenhouse gas inventory, it is difficult to accurately determine how much of these emissions were produced by the University as a whole. Though EPA data shows that Yale contributed to 13.7 percent of New Haven’s overall greenhouse gas emissions through its two power plants, it also contributes to the city’s emissions through other avenues such as bus and commuter transport.

Mitchell-Ward and Lerner described the technicalities of how Yale could make the transition to renewable energy.

First, they said Yale could retrofit, or add new technology to, the existing power plants. The power plants could run on “some new blend of fuel that might come from biomass gasification or ‘renewable natural gas’ captured from landfills,” Mitchell-Ward said. He acknowledged that this retrofitting process might be expensive — but necessary — to make Yale’s energy grid fully carbon-zero. 

Yale’s power plants currently burn natural gas, but many other universities have heat and power facilities powered by renewable fuels. Middlebury College, Green Mountain College, Northern Michigan University and Eastern Illinois University use wood as a source of renewable fuel. The University of California, Davis uses landfill gas and The State University of New York College of Environmental Science and Forestry, University of Wisconsin-Oshkosh and the College of Wooster all use digester gas.

Second, Yale could decommission the existing power plants and build new facilities to generate and store solar energy. Mitchell-Ward believes this should be Yale’s “primary strategy.” 

Lerner estimated that it would take around one to two years and cost between $25 million and $35 million to build and develop such facilities. Though at present, it might be cheaper for Yale to run its existing power plants, Lerner added that in the long run, a new solar project would be cheaper than “running existing dirty infrastructure.”

Other universities have embarked on solar energy projects. In 2020, the University of Pennsylvania signed a Power Purchase Agreement to create a solar power project that will provide about 75 percent of the campus’ electricity demand. 

Mitchell-Ward added that Yale could make a “more immediate climate positive impact” by following in the footsteps of the University of Pennsylvania and signing a wind or solar agreement to bring more renewable energy to Yale at a utility-scale level, in addition to Yale’s existing small on-campus solar installations.

Allegheny College, American University, Bates College, Bowdoin College, Colby College, Colgate University, Colorado College, Dickinson College, Middlebury College and the University of San Francisco have all achieved carbon neutrality as of 2020. Yale plans to have net zero emissions by 2035 and to reach zero carbon emissions by 2050.

“It’s like there’s a factory that’s emitting a lot of smoke,” said Chris Schweitzer, activist and director of the New Haven Leon Sister City Project. “And they find out a lot of families are dying and getting sick from that smoke. And the factory comes back and says, ‘Oh, we got a solution. We’ll cut that smoke by five percent each year over the next 20 years.’ The families are like, ‘wait a minute, we’re getting sick and dying now.’”

University President Peter Salovey acknowledged the need for energy innovation in a June 2021 email addressed to members of the Yale community. 

“Yale intends to be at the forefront of universities in utilizing power plant turbines fueled by non-fossil fuels,” Salovey wrote. “Similarly, Yale will be an early adopter of innovations that advance the drive to electrify thermal loads, such as the next generation of geothermal energy systems.”

The Central Power Plant was built in 1918 and the Sterling Power Plant was built in 1923 on the Yale School of Medicine campus.

Charlotte Hughes reports on climate and environmental issues in New Haven. Originally from Columbia, South Carolina, she is a freshman in Branford College majoring in English.