RTZC Frequently Asked Questions
The Roadmap to Zero Carbon is an ambitious vision that will help Swarthmore College eliminate 98 percent of greenhouse gas emissions from on-site fossil fuel combustion and purchased electricity, in order to reach our goal of carbon neutrality by 2035.
- Is Swarthmore College carbon neutral?
In 2010, the College committed to achieving carbon neutrality no later than 2035. Significant steps have been taken since then to improve overall campus energy efficiency. The Energy Plan is Swarthmore’s plan to take this commitment to carbon neutrality to the next level.
- What will the Energy Plan do?
The energy plan will eliminate most on-campus fossil fuel combustion by transitioning to electrified, reliable, and decarbonized renewable energy for the Swarthmore College campus. These changes will result in less than 50,000 metric tons of carbon dioxide equivalents (MTCDE) released into the atmosphere from the College over the next 30 years versus the 350,000 MTCDE released if the College does nothing.
- How much will the Energy Plan cost?
The projected cost of implementation is estimated to be $69 million.
- How does the geoexchange plant fit into the Energy Plan?
The geoexchange plant will replace Swarthmore’s high-pressure steam system which provides heat to campus buildings. Originally built in 1911, the steam system is antiquated and relies on the combustion of fossil fuels, mostly natural gas, to function. In contrast, the geoexchange system is a highly efficient zero-carbon energy system. Replacing the outdated steam system with the geoexchange system — including the geoexchange plant, heat pumps, and heat recovery systems — is a key part of making our campus energy efficient and combustion-free.
- If the new plant is electric, where will the carbon-free electricity to power the plant come from?
Swarthmore College is working with other local colleges to develop an off-site renewable energy generation facility using solar photovoltaic technology that will put new, renewable electricity onto our electrical grid equivalent to the College’s projected electrical demand. Our electrical grid is operated by PJM Interconnection, a company that operates the electrical grid for all or parts of Delaware, Illinois, Indiana, Kentucky, Maryland, Michigan, New Jersey, North Carolina, Ohio, Pennsylvania, Tennessee, Virginia, West Virginia and Washington, D.C.
The planned geoexchange system is how Swarthmore will provide combustion-free heat to its buildings in the winter and cool them in the summer. It will replace the outdated, inefficient, and carbon-intensive, high-pressure steam system powered by combusting fossil fuels.
- How Does the Geoexchange System Work?
A geoexchange system moves heat out of buildings to store in the ground in the summer, and removes the stored heat from the ground to heat buildings in the winter.
At Swarthmore, we will have hundreds of geoexchange wells which are essentially deep holes with a vertical pipe closed loop in them. As liquid travels through the pipes, it is either depositing thermal energy into the earth (summer) or extracting thermal energy from the earth (winter). That heated or cooled liquid is then sent across campus to individual buildings where the traditional HVAC systems turn it into the hot or cold water or air that heats or cools our buildings.
The geoexchange system works on a yearly cycle by which heat-recovery chillers, powered by renewable electricity, remove heat from campus buildings during summer and store the heat in the earth through deep ground wells. The heat is then extracted from the earth in the winter to heat campus buildings.
The new Dining and Community Commons includes space for a central geothermal exchange plant (“geoexchange plant”) which will be the heart of the heating and cooling systems for the entire campus.
- Where will it be?
The plant will be located in the basement of the new Dining and Community Commons — specifically, the basement of the addition to Sharples Dining Hall that will become the new central dining facility on campus.
The geoexchange plant was integrated into the Dining and Community Commons because of its central campus location and proximity to the proposed site for geoexchange wells beneath the Parrish lawn. In addition, the integration of the dining hall and geoexchange plant saves the College money because a standalone geoexchange plant building would cost more than the basement addition to the Dining and Community Commons.
- What will be in the plant?
The plant is where all the large equipment to run the geoexchange system will be housed. There will be lots of pipes, wiring, pumps, tanks, heat-recovery chillers, and a sophisticated control system, though it won’t look like much is happening to the casual observer.
- When will the geoexchange plant be built?
The basement to house the geoexchange plant, which is over 13,000 square feet, is currently under construction as part of the Dining and Community Commons addition. The dining addition is slated to open in the fall of 2022.
Integral to the geoexchange system are the geothermal wells. The wells are essentially pipes with liquid running through them. The mass of the earth and constant temperature (50 degrees Fahrenheit) acts as a thermal storage mass for heat extracted from campus buildings during summer cooling that can then be extracted in the winter to heat buildings. Currently the extracted summer heat is exhausted to the atmosphere through evaporative cooling. The energy plan will also save the college millions of gallons of water annually that is used for evaporative cooling.
- Where will the wells be installed?
All of the wells will be underneath Parrish lawn. They will be drilled in phases to meet the geoexchange load as campus buildings are converted to low temperature hot water heating over the thirteen-year plan implementation. The last well field zone is underneath the Ben West parking lot and this location may be needed if the College expands its building space.
- When will the wells be drilled?
Drilling of the boreholes for the geothermal wells may begin as early as the summer of 2022. Sound mitigation measures will be taken to minimize the sounds of drilling while classes are in session.
- How big will the wells be?
The wells will be 600 feet deep and approximately 10 inches wide.
- How many wells will there be?
There may be up to 900 wells over more than 200,000 square feet across campus.
- Will you be able to see the wells?
After drilling is complete and the lawn is restored, you will not be able to see the wells.