Central Energy Plants

Salas O’Brien’s geothermal design for Princeton University’s historic west campus and new east campus included providing analysis of infrastructure, university energy, economic, and environmental impact policies, and predictive modeling to establish a basis for infrastructure conversion and expansion projects that will reduce greenhouse gas emissions.

Upon addition of a specified third and fourth 1,750-ton CYK heat pump chiller in 2026, the new TIGER (Thermally Integrated Geo-Exchange Resource) energy facility on the east campus will provide 7,000 tons of cooling and 113,960 MBH heating capacity solely from the currently installed 583-bore geothermal system (850-foot depth) augmented with two 2.25M gallon thermal energy storage tanks (19,680 ton-hours cooling; 421,123 MBH heating), with distribution piping sized for 2,310-bore total capacity. These measures will substantially advance Princeton toward its 2046 carbon neutrality target date, coinciding with the school’s 300th anniversary.

Completion Year



9.5 million square feet

Construction Cost

$9.5 million



Cooling from geothermal system

Heating capacity