Geothermal Conversion

In its 2011 Climate Action Plan, Carleton College pledged to become carbon-free by 2050. Salas O’Brien worked with Carleton to develop its 2016 utility master plan to chart a multi-year, multi-phase course for doing so. Since then, Carleton has become the first college campus to transition off steam entirely and the first college campus to install a district energy-scale geothermal system.

The new system of borefields located throughout the campus, capable of supporting simultaneous heating and cooling, enabled the transition to a 120°F heating hot water system. Peak heating and cooling demand can be met with supplemental new high-efficiency gas-fired boilers and the existing chiller. This comprehensive utility project is housed in a new primary-source energy station incorporated as the sub-basement of Carleton’s new science building.