The European horticulture sector in the Westland and NRW Straelen corridor is accelerating its transition away from fossil natural gas CHPs toward Aquifer Thermal Energy Storage (ATES / Warmte Koude Opslag) paired with large-scale industrial heat pumps. By capturing summer surplus solar heat from greenhouse roofs and storing it at depths of 40–120 meters, ATES delivers seasonal recovery efficiencies exceeding $80\%$, elevating heat pump Seasonal Performance Factors (SPF) beyond $5.2$.
1. ATES Doublet Thermal Capacity & Hydrogeology
An open-loop ATES system utilizes a warm well ($T_{warm} \approx 16–18^\circ\text{C}$) and a cold well ($T_{cold} \approx 7–9^\circ\text{C}$) drilled into porous sandy aquifers. The seasonal thermal energy stored is defined by:
Q_{stored} = V_{water} \cdot \rho_w \cdot c_w \cdot (T_{warm} - T_{cold}) \cdot \eta_{recovery}
Where $V_{water}$ is the annual pumped water volume ($\text{m}^3$), $\rho_w \cdot c_w \approx 4.186\text{ MJ}/(\text{m}^3 \cdot \text{K})$, and $\eta_{recovery}$ is the seasonal thermal recovery factor ($0.75–0.85$).
2. Heat Pump Carnot & Lorenz COP Modeling
When lifting low-grade aquifer heat ($16^\circ\text{C}$) to low-temperature pipe rail supply ($40–45^\circ\text{C}$), the real Coefficient of Performance ($COP_{real}$) dramatically outperforms air-source heat pumps during sub-zero winter peaks:
COP_{real} = \eta_{carnot} \cdot \frac{T_{condenser} + 273.15}{(T_{condenser} + 273.15) - (T_{evaporator} + 273.15)} \approx 0.55 \cdot \frac{318.15}{318.15 - 289.15} = 6.03
3. Interactive Heating & Energy Engineering Hub
Explore full heating load, buffer storage, and decarbonization calculators: