ATES: a sustainable solution for heating and cooling
Year on year, energy efficiency regulations are getting stricter. Building operators and facility managers face rising compliance costs and systems that struggle to keep up. It’s increasingly clear that traditional, fossil-fuel-based heating and cooling will not meet tomorrow’s standards.ATES: a sustainable solution for heating and cooling
Year on year, energy efficiency regulations are getting stricter. Building operators and facility managers face rising compliance costs and systems that struggle to keep up. It’s increasingly clear that traditional, fossil-fuel-based heating and cooling will not meet tomorrow’s standards.
Aquifer Thermal Energy Storage (ATES) tackles these problems head-on. The technology draws from underground water sources that stay at consistent temperatures, storing and supplying heating and cooling energy throughout the year, thus cutting consumption, costs, and carbon.
At Equans, we design, deliver, and maintain ATES systems for commercial and industrial sites. Our clients see their energy bills drop while their carbon emissions fall too. The technology operates smoothly, requires little upkeep, and performs the same way whether it's scorching hot or freezing cold outside.
What is ATES and how does it work?
Aquifer Thermal Energy Storage is a shallow geothermal technology that taps into natural underground water reservoirs to store and retrieve thermal energy for seasonal heating and cooling. The system pumps groundwater from underground aquifers, extracts or adds heat energy, then returns the water to storage.
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During the summer, ATES captures excess heat from buildings and stores it underground.
- Come winter, that stored heat gets pumped back up to warm the same buildings.
- The process reverses for cooling: the cool temperatures from the winter are used to provide relief during the hotter months.
Think of it as nature's own rechargeable thermal battery. Instead of burning gas or running electric chillers around the clock, ATES borrows from the earth's stable underground temperatures. The aquifer can hold onto thermal energy for months, ready to deliver it when buildings need it most.
Storing excess heat in summer
Commercial and industrial buildings generate significant unwanted heat in summer. Most facilities let it slip away, but ATES captures that heat via a groundwater circulation system.
The process uses a network of wells that tap into underground aquifers at depths that vary by system type. ATES systems typically operate between 50-200 metres for a single building or compact site. Cool groundwater is pumped up from the “cold” aquifer, which commonly stays near 13°C in shallow systems. The heat pump takes the building’s excess heat and transfers it into the groundwater, raising the temperature to around 18°C or higher. The warm water is then injected back through wells into a separate “warm” aquifer.
Once underground, that heated water spreads through porous rock formations. The aquifer becomes a large underground storage tank holding thermal energy for months. Rock and soil act like natural insulation, keeping the heat from dissipating.
Recovering heat in winter
Winter sees the process operate in reverse. Pumps extract the stored warm water from the underground reservoir, and the 18°C water travels back to the surface through the same well network. At the heat pump, the system extracts thermal energy from the groundwater and lifts it to 35-45°C, suitable for building heating systems.
The cooled groundwater, now back down to its original 13°C, returns to the cold aquifer through injection wells. The cycle creates a continuous loop between two separate underground storage areas. One holds warm water, the other holds cold water, with the heat pump managing the energy transfer between them.
Why choose ATES for commercial and industrial buildings?
Under pressure to decarbonise quickly and contain costs, building operators and facility managers are caught between a rock and a hard place. Aquifer Thermal Energy Storage offers a practical way out, using underground thermal storage to rethink conventional energy management.
The economics stack up
The opportunity is significant. The U.S. Department of Energy reports that 30% of energy used in commercial buildings gets wasted. ATES systems tap into that waste and turn it into thermal storage.
ATES systems often achieve seasonal performance factors (SPF) of between 3-5, well [IP1] [IP2] above traditional boiler-chiller setups, and can deliver seasonal energy efficiency ratios (SEER) of over 60, which is roughly four to six times more efficient than conventional cooling systems.
Commercial geothermal systems typically see payback periods of 5-10 years, with some systems delivering in as little as 5 years due to lower operational costs. Over 20-year lifecycles, total cost of ownership outperform conventional systems.
Reliability you can bank on
Ground temperatures stay at 10-15°C all year long. The surface weather changes, but underground conditions remain constant. When heat waves drive up grid demand and equipment starts failing, your system continues operating. Likewise, cold snaps that overwhelm conventional heating systems won't affect your operations.
Facility managers know summer cooling breakdowns happen when demand peaks and repair costs climb. And winter heating failures can often bring operations to a halt. ATES reduces these risks. The ground provides consistent performance compared to weather-dependent systems that struggle with seasonal extremes.
One system does it all
ATES eliminates the need for separate heating and cooling equipment. You don't need boilers, chillers, or gas lines. The underground system handles both heating and cooling by moving thermal energy between the building and the ground.
For maintenance, it comes down to pumps and heat exchangers. That's it. Gone are the days of dealing with combustion equipment or refrigeration systems that break down.
Unlike closed-loop ground-source heat pump (GSHP) systems, which circulate a fluid through buried pipes to extract ground heat, ATES pumps actual groundwater between two underground aquifer zones. This open-loop approach enables far greater seasonal thermal storage capacity, making ATES the practical choice for large commercial and industrial buildings where a closed-loop system would be technically and economically unviable.
Keeping ahead of regulations
Carbon mandates are tightening, not going away. ATES allows you to stay ahead of compliance requirements instead of playing catch-up as 2030 and 2050 deadlines loom.
Aquifer Thermal Energy Storage systems cut emissions significantly compared with what most buildings run on today. For your bottom line, this translates into smoother routes to green building credentials, renewable energy certificates, and carbon credits, without the usual retrofit chaos. You also avoid ripping apart plant rooms or shutting down operations for complex upgrades
Schiphol Airport faced a familiar challenge in meeting aggressive decarbonisation targets without compromising operational performance. With carbon neutrality mandated by 2030, the airport required proven technology that could deliver measurable results at scale.
The airport deployed ATES across its facilities. Post-implementation data shows a 60% reduction in heating and cooling energy consumption, with gas usage falling 45% from 2019 baseline levels. These metrics show sustained performance over multiple operational cycles, not just initial test results.
The project revealed key insights for similar facilities. ATES integration works best when coordinated with existing infrastructure rather than via wholesale replacement. Schiphol’s shallow geothermal system now carries primary responsibility for climate control, with fossil systems retained for peak demand and resilience.
The economic case proves equally compelling. Reduced energy costs generated working capital for additional sustainability investments while meeting regulatory requirements. This dual benefit addresses the resource allocation challenge most facilities face when pursuing comprehensive decarbonisation.
Equans’ deployment record across the Netherlands encompasses over 700 ATES installations. Schiphol sits at the upper tier of complexity as a high-volume environment where system reliability directly affects business continuity. Its sustained performance shows ATES can operate under the demanding conditions of aviation, one of the most complex sectors for climate control.
Wider European ATES deployment opportunities
Europe’s geology supports widespread ATES adoption, where favourable subsoil conditions, particularly sandy formations with accessible groundwater, can serve thousands of commercial facilities.
Industrial estates, healthcare facilities, and business parks show strong suitability. Beyond adequate groundwater access, existing infrastructure often accommodates ATES integration without major modifications.
Economics are driving adoption as much as environmental factors. Operational savings alone make a convincing argument, while environmental benefits from reduced fossil fuel consumption follow naturally, without premium costs.
At Equans, we support Aquifer Thermal Energy Storage projects end to end, from feasibility and permitting through design, delivery, and maintenance, with a single point of contact. Our teams have delivered low carbon thermal systems in airports, hospitals, universities, and commercial real estate. Contact us to discuss your ATES potential and next steps.
Frequently asked questions about ATES
Commercial ATES projects typically reach payback in 5-10 years, with some sites achieving it in as few as 5 through lower operational costs. Over a 25-30 year lifespan, total cost of ownership consistently outperforms conventional boiler-chiller setups.
ATES works best for large buildings with year-round heating and cooling demand: offices, hospitals, airports, industrial estates. It requires access to a productive aquifer and enough site area for two wells. A feasibility study is the first step.
Ground-source heat pumps extract ground heat through buried pipes, they don't store energy seasonally. ATES pumps actual groundwater between two aquifer zones, enabling far greater storage capacity and making it the practical choice for large commercial sites.
Schiphol Airport recorded a 45% drop in gas consumption following deployment. For most buildings replacing gas-based systems, ATES reduces heating and cooling emissions by 50-70%.
