Storing data center heat underground: Epic Systems' two-decade experiment

Epic Systems in Verona, Wisconsin, has drilled roughly 6,100 wells 300–800 feet deep to bank summer waste heat from a 3.5 MW data center in rock and recover it in winter to heat about 40 campus buildings. The U.S. Department of Energy reports Epic's buildings use about 25% less energy than comparable buildings in the same climate.

• About 6,100 wells 300–800 feet deep serve 40 campus buildings
• Summer server heat is pushed into rock and recovered in winter at ~59 F
• Epic's buildings use about 25% less energy than peers in the same climate
• Scale is small: 3.5 MW versus AI campuses of 100–1,000 MW