Princeton University is converting its campus from steam to hot water to improve energy efficiency. | Photo Credit (all): IDEA
By Rob Thornton, President & CEO, International District Energy Association (IDEA)听
Over the last two decades, colleges and universities have done serious work on climate. Many have cut emissions, purchased renewable electricity, upgraded lighting and controls, and improved building performance. They have also set bold targets to achieve carbon neutrality by 2030, 2035 or 2040. Higher education understands its role as a laboratory for innovation and leadership.听
And yet, in facilities meetings across the country, a familiar moment is playing out. Someone puts the original decarbonization roadmap on the table and says, 鈥淲e need to revisit this.鈥�听
That鈥檚听not a failure of ambition.听It鈥檚听a reflection of campus reality. Colleges and universities are complex 鈥渕ini-cities,鈥� balancing aging infrastructure, deferred maintenance, new construction, enrollment shifts, research growth, tight capital听budgets听and a changing climate that is driving higher cooling loads and more demanding resiliency expectations. Add grid constraints and volatile energy markets, and even well-built plans can drift off schedule.
The question听isn鈥檛听whether campuses can decarbonize.听It鈥檚听whether they can do it at scale, reliably, and at a cost they can live with, while keeping students,听faculty听and patients comfortable on the hottest day of the year and the coldest night of the winter.听
That鈥檚听where district energy comes into听the conversation.听听
District energy is a shared thermal infrastructure for heating and cooling. Instead of each building owning its own boiler, chiller, cooling tower听and control strategy, a campus can serve multiple buildings from a central facility that distributes steam, hot听water听or chilled water through an underground piping network. Aggregating thermal loads is the foundation that makes decarbonization,听resilience听and campus growth easier to deliver in practice.听
District Energy鈥檚 Advantages and Opportunities听
Most campuses manage dozens, sometimes hundreds, of buildings with different vintages and uses. If each building must solve heating and cooling on its own, the result is predictable: redundant equipment, oversized capacity, scattered maintenance听risk听and replacement cycles that rarely align with the institution鈥檚 long-term carbon strategy.听听
On the cooling side, building-level chiller plants are commonly sized with 30% to 100% more capacity than a comparable district cooling solution, because each building must plan for its own peak. When you aggregate loads, peaks diversify. The system can be sized and听operated听for overall performance, not individual buildings. That translates into higher efficiency, lower peak electric听demand听and lower lifecycle cost.听
On the heating side, district energy creates optionality. A central facility can integrate multiple heat sources over time, including combined heat and power (CHP), high-efficiency boilers, electric boilers, industrial heat pumps, geothermal exchange, wastewater听heat听and waste-heat recovery from data centers. The 鈥渞ight鈥� technology can evolve as markets and policies evolve, without forcing every building to undergo a complete mechanical reinvention at the same time.听
There鈥檚听also a campus construction benefit: district energy is a real estate strategy.听
When you reduce rooftop chillers and cooling towers and shrink basement mechanical rooms, you give the institution valuable space back. That space becomes labs, classrooms, patient care, storage, amenities听or simply less congestion for maintenance staff. It also reduces noise and vibration, improves architectural听flexibility听and makes it easier to renovate historic buildings without fighting the constraints of modern HVAC equipment.听
Resilience is another differentiator. District energy systems can be designed with N+1 redundancy, multiple fuel听pathways听and thermal energy storage (chilled water,听ice听or hot water) that decouples production from use. For a campus, this strengthens the ability to ride through grid disturbances, extreme听weather听and peak pricing events while prioritizing mission-critical loads.听
Just as important, district energy can be built in phases, which aligns with how campuses are built鈥攐ne project at a time, one renewal cycle at a time, guided by a master plan. Instead of treating HVAC replacements as disconnected emergencies, district energy turns them into a coordinated capital program: plant modernization, distribution听expansion听and standardized building energy transfer stations. When planned early, this reduces rework, simplifies future tie-ins听and keeps projects moving even when a building schedule slips.听
Where District Energy Is Driving Impact听
Across the country, universities are听demonstrating听what modern district energy can achieve.听
Cornell University built a global reference project with Lake Source Cooling, using cold deep lake water to meet a large share of campus cooling needs, reducing electricity听consumption听and avoiding traditional refrigerants. Cornell is now advancing Earth Source Heat, a deep geothermal initiative designed to meet most annual heating demand and sharply reduce reliance on fossil fuels. The lesson is clear: start with an innovative anchor project, then build the next layer.听
Princeton University is converting its campus from steam to hot water, improving distribution听efficiency听and supporting lower-temperature听operation. Its TIGER and CUB projects are designed to integrate heat pumps and geo-exchange, paired with renewable power resources and microgrid capability.听Converting听an entire campus is not quick, but Princeton shows how a multi-year program stays coherent when each phase ties back to a long-term thermal strategy.听
The University of Virginia highlights a complementary truth: efficiency and district energy are partners, not competitors. UVA has delivered significant reductions through sustained building-efficiency efforts (controls, retro-commissioning, targeted retrofits) and upgrades to central facilities. The result is听smaller,听smarter loads served more efficiently and cost-effectively.听
Read four key lessons for campus leaders and project teams in the Higher Education Edition of 糖心少女.
Rob Thornton has served as President & CEO of the International District Energy Association (IDEA) since 2000. With听nearly four听decades听in听district energy, he works with campus and city leaders to advance efficient, resilient, low-carbon thermal infrastructure.听