Strategy
Four Principles of Energy Resiliency
Dartmouth’s energy strategy centers around four main principles. We are drastically reducing our energy consumption, changing the way we distribute heat to buildings, implementing new geo-exchange and solar thermal technologies, and transitioning to low-emission electricity sources. We will also upgrade campus electrical systems and back-up generators to make the whole system resilient against shocks in the grid.
1. Reduce Energy Demand
We are continuously reducing energy use in buildings through a wide array of energy conservation projects including LED lighting, heat recovery, building controls upgrades and other improvements. These projects have helped Dartmouth reduce its emissions by about 30% since 2010.
2. Steam to Hot Water Transition
We will replace all steam distribution piping with new hot water piping, which is a much more efficient way to distribute heat from the central plant to campus buildings. Steam will also be eliminated from building heating systems, in addition to other energy efficiency improvements.
3. New Heat Sources
Transitioning to hot water enables the use of geo-exchange heat pumps which capture “waste” heat from the chilled water system and transfer it directly into the heating system. The system deposits excess heat into the ground in summer or withdrawn in winter via geo-exchange bore fields. Thermal storage tanks and solar thermal panels will provide additional combustion-free heating and cooling capacity.
4. Low-Emission Electricity
We will utilize low-emission electricity sources, through a combination of on campus renewable electricity technology and procured off-site renewable electricity sources, to power the heat pumps, hot water pumps, and other campus electrical systems.
What is Geo-Exchange?
On most campuses, a large portion of overall energy consumption is used to heat and cool buildings. Geo-Exchange is a highly efficient technology used for that very purpose.
Geo-exchange works like a heat storage piggy bank.
In summer, excess heat is drawn out of buildings, making them feel cooler and more comfortable. This heat is transferred to water that is pumped deep underground in a closed loop pipe system. The heat warms surrounding rock and soil, using the earth to store that heat until it is needed in colder months. When the weather gets chilly, the pipes draw heat out of storage and transfer it into the buildings using an electric heat pump.
Why is it a good choice for Dartmouth?
Dartmouth’s geoexchange plan provides yearround heating and cooling by moving heat to where it’s needed or storing it in the ground. Watersource heat pumps tied to geoexchange borefields increase system efficiency and lower operating costs. Because it relies on distributed borefields and modern equipment, the geoexchange system will be more resilient and reliable than our aging steam infrastructure. In addition, the system can operate on renewable electricity, reducing emissions as we modernize.