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91ֱ�� College & Conservatory will take an important step toward carbon neutrality this summer as it launches a multi-year, campus-wide conversion to geothermal energy, positioning the institution as a national leader in clean energy.

The $140 million, four-year project will begin next month with the installation of new heating and cooling systems in South Campus buildings, and ultimately involve the drilling of about 1100 geothermal wells that will effectively heat and cool campus buildings. 

When complete, the project will bring 91ֱ�� within reach of its ambitious goal to become carbon neutral—using education and behavior change strategies, efficiencies, and clean energy sources, to bring the institution’s net release of carbon dioxide to zero—by 2025.

It will also replace failing, century-old infrastructure with a system that will bring air conditioning to more buildings, improve the temperature control across campus, bolster reliability, and save more than $1 million a year in energy costs.

“We had to act, so we did this the 91ֱ�� way,” wrote President Carmen Ambar in a message to students, faculty, staff, and alumni. “We started with a rigorous, exhaustive examination of every possible option. Then, armed with that data, our trustees made a bold decision that will not just fix the problem—it will show other large institutions across the country that it is possible to improve living and working conditions for students, faculty, and staff, while addressing a global challenge that touches all of us.”

“Obies care deeply about our collective impact on the environment,” said Meghan Riesterer, assistant vice president for campus energy and sustainability. “This is a collaborative solution developed by representatives from across our community, together with experts.”

Riesterer said one of the project’s most exciting elements is the educational opportunities it creates. 91ֱ�� students have been an integral part of the project planning already. The project will also be a subject for coursework in environmental studies, geology, psychology, and the new business concentration.

In 2006 91ֱ�� was one of the first institutions to sign the Carbon Commitment (formerly the American College and University Presidents’ Climate Commitment), pledging to dramatically reduce harmful emissions by 2025, decades ahead of many other signatories. The college has already cut its carbon use in half, through efficiencies in power and heating use, a significant solar-power project, and a transitional conversion from coal-fired heat to natural gas.

Even as it made those changes, 91ֱ�� continued to work toward a more comprehensive, carbon-free source of thermal energy. At the same time, the deterioration of steam pipes installed a century ago has accelerated, adding urgency to the work.

In 2016 the college released a new master plan for sustainable infrastructure, which analyzed a variety of options for both the heating system and its principal source of energy. In March, trustees approved a plan that modernizes 91ֱ��’s “energy district” approach, which uses a single source of heat and cooling for most campus buildings, as well as several nearby buildings that purchase their heating energy from the College.

In addition to geothermal heating and cooling and supporting infrastructure, the $140 million estimate also covers significant upgrades to the college’s electrical system and information technology infrastructure, which will cost less if combined with the geothermal project. Funding sources are expected to include long-term debt financing, federal grants, tax credits, and other possible outside sources, subject to trustee approval.

The thermal conversion begins with a transition from an outdated steam system to a “low-temperature,” closed-loop system that moves 120- to 140-degree water from the energy source and across campus, with much lower loss in temperature and water, and the flexibility to bring heat and cooling where it is most needed at any given moment. 

That system will require retrofitting heating systems within each building, as well as replacing more than 9 miles of underground piping across campus. Campus facilities leaders have said they will use this opportunity to upgrade other technologies within each building, including digital infrastructure and fire protection systems.

As that infrastructure work is underway, the project will convert the boiler plant to tap geothermal energy, using current equipment as a natural-gas backup, and culminate with the drilling and installation of the geothermal wells north of the college’s athletics practice fields. Drawing water through a closed loop from 600 feet underground, where the temperature is a constant 55 degrees Fahrenheit, pumps will then deliver it to state-of-the-art heat exchangers, which are boosted by electricity from 91ֱ�� Municipal Power and Light and are nearly 90 percent carbon-free. 

Work begins this summer with the conversion of buildings on South Campus, while they are not in use. The work will then proceed roughly clockwise, to West and Central Campus, and on to completion.

The transition also will reduce 91ֱ��’s water use by more than 5 million gallons per year, reduce sewer discharge by more than 4 million gallons per year, and improve campus energy efficiency by over 30%. 

In addition, there is potential to extend this carbon-neutral system to serve the broader community.  Throughout the planning process, college leaders have worked closely with city leaders. This additional geothermal heating source will better position the City of 91ֱ�� to meet its City Climate Action Plan goals. 

This project is being done in partnership with Ever-Green Energy, a Minnesota-based company focused on advancing and operating energy systems.

For more information about the Sustainable Infrastructure Program including construction updates, visit .