The cost of producing heat from the HT-ATES is calculated using a net present value model (discounted cash flow model), which is the same as used for ThermoGIS geothermal but with different input values. It assumes that the heat stored in the HT-ATES is free. The economic model uses a number of Parameters.
The CAPEX consists of well costs, base (installation) costs, and variable costs depending on the installed pumping capacity. The well costs are depth-dependent and are determined using the following formula:
Well CAPEX = 100,000 + 1000d + 0.3d2
Where d is the depth of the well (in meters).
The OPEX depends on the electricity consumption of the pumps, maintenance, monitoring and water treatment costs.
The net present value model calculates the cost price (UTC) per unit of (heat) energy [€ct/kWh].
The economic potential is then calculated by comparing this cost price with reference prices. These reference prices are 5.6 €ct/kWh, in line with the SDE amount for geothermal energy and the maximum heat price according to ACM of 13.3 €ct/kWh. This yields the following classes:
| Cost price class | Value | Reference | Source |
| low | < 5.6 €ct/kWh | SDE++ correction amount geothermal energy 2024 | PBL (2023) |
| medium | 5.6 - 13.3 €ct/kWh | ||
| high | > 13.3 €ct/kWh | ACM maximum heat price 2024 (excl. tax) | ACM (2024) |
* note that these cost price classes are different for HT-ATES than for geothermal,as for HT-ATES only the P50 is calculated, and the UTC is compared with a min and max heat price.