Building energy independence at the Utrecht Science Park

At the Utrecht Science Park, five institutions are joining forces to develop a collective aquifer thermal energy storage system (ATES). With this initiative, they are taking an important step toward a future-proof, largely fossil-free energy system. A thermal source for heating and cooling is currently being installed to connect the first buildings. By 2030, several more buildings are expected to be linked to this shared infrastructure. By mutually sharing heat and cold, the campus will significantly reduce its reliance on natural gas and external energy sources.

According to Katelien van den Berge, an independent energy systems researcher who studied the project as part of a comparative analysis of low-temperature district heating networks in Dutch cities, it is the collaboration that truly stands out. “It’s an impressive development,” she says. “Not so much because of the technology itself, but because of the scale of cooperation, the long-term vision, and the courage to start implementing it now.”

This is exactly the kind of systemic approach Utrecht needs to gradually reduce dependence on fossil fuels.

Storing energy underground

The principle behind an aquifer thermal energy storage (ATES) system is relatively straightforward. Instead of generating heat and cooling on demand, the system stores thermal energy in groundwater reservoirs and distributes it later through a shared network of wells and heat exchangers to connected buildings.

The system uses two separate groundwater wells: one for heat storage and one for cold storage. In summer, water from the cold well is used to cool buildings. The heat released during this process is stored in the warm well. In winter, the stored heat is pumped back up to warm buildings, while the cooled water flows back into the cold well. In this way, heat and cold are preserved between seasons rather than lost, enabling continuous reuse.

Surpluses of heat or cold in one building can be used to offset shortages in another.

The real efficiency gains emerge once multiple buildings are connected to the same ATES system. “Surpluses of heat or cold in one building can be used to offset shortages in another,” explains Jolt Oostra, Energy Portfolio Manager at Utrecht University. “This significantly reduces the need for natural gas, lowers CO₂ emissions, and cuts energy costs.”

More efficient together

ATES systems are not new in the Netherlands. What makes the system at the Utrecht Science Park unique is the scale and intensity of the collaboration behind it. “There were already ATES systems in place at the USP,” Oostra explains. “But they were managed separately by different organisations. Over the past few years, five institutions have worked together to integrate these systems into a single, shared network.”

The partners are Utrecht University (UU), Hogeschool Utrecht (HU), Stichting Studentenhuisvesting (SSH), International School Utrecht (ISU), and University Medical Center Utrecht (UMC Utrecht).

Construction of the first underground heat and cold source is currently underway, providing sufficient capacity to connect the first buildings to the collective ATES system: the Utrecht University Library (UBU), International School Utrecht, and Hogeschool Utrecht. The system is designed to grow alongside the campus’s energy needs. “The more diverse the energy profiles of the connected buildings, the more efficient the system becomes,” says Oostra. “A building that generates a lot of residual heat can help warm nearby classrooms. Heat released when cooling buildings with high solar exposure can be reused elsewhere on campus for heating.”

Part of the broader energy transition

Alderwoman for Energy and Climate Senna Maatoug emphasises the wider significance: “Our city is growing rapidly. That means we need to use energy—and the limited space in our subsurface— in a smarter way. Collective systems like the one at the Utrecht Science Park demonstrate how collaboration enables us to build more efficiently, sustainably, and with the future in mind. This is exactly the kind of systemic approach Utrecht needs to gradually reduce dependence on fossil fuels.”

The municipality brought the parties together, facilitated discussions, and provided a one-off subsidy to make the collective solution possible. Although a shared infrastructure requires greater upfront investment than separate systems, it delivers long-term societal benefits: more efficient use of underground space, reduced energy losses, and improved opportunities to exchange heat and cold.

An example beyond Utrecht

That greater vision is most striking to Katelien van den Berge, now that she is working as a program manager at Collectieve Warmte Amsterdam (CWA) on the upscaling of thermal energy systems. “I have great admiration for Utrecht University and all the collaborating partners,” she says. “It isn’t easy, and it takes time. But I am convinced that in the end it will pay off—economically, ecologically, and socially.”