To Slash Carbon Emissions, Colleges Are Digging Really Deep

When administrators at Princeton University decided to cut the carbon emissions that came from heating and cooling their campus, they opted for a method that is gaining popularity among colleges and universities.

They began drilling holes deep into the ground.

The university is using the earth beneath its campus to create a new system that will keep buildings at comfortable temperatures without burning fossil fuels. The multimillion dollar project, using a process known as geoexchange, marks a significant shift in how Princeton gets its energy, and is key to the university’s plan to stop adding greenhouse gases to the atmosphere by 2046.

The drilling makes an almighty muddy mess, but when all is said and done, the more than 2,000 boreholes planned for the campus will be undetectable, despite performing an impressive sleight of hand. During hot months, heat drawn from Princeton’s buildings will be stored in thick pipes deep underground until winter, when heat will be drawn back up again.

The change is significant. Since its founding in 1746, Princeton has heated its buildings by burning carbon-based fuels, in the form of firewood, then coal, then fuel oil, then natural gas.