Measured electrical conductivity of the groundwater at a defined depth interval or for a single point in depth.

The intrinsic ability of hard rock samples to conduct heat.

Thermal response test (TRT) is the customary method to determine ground thermal conductivity in situ.

Specific annual thermal energy content for heating and / or cooling referring per surface area for borehole heat exchangers at a defined length.

The maximum temperature shift between the production and the injection well that is possible with regards to legal or ecological limitations.

Measured effective average interval thermal conductivity also accounting for advective heat transport caused by groundwater. The data is obtained from Thermal Response Tests.

Thermal capacity of a well doublet for heating and/or cooling depending on the hydraulic productivity and the thermal productivity.

Overall evaluation of possible limitations and restrictions to the installation of open loop systems based on a 4 colour schemes (grey: no data available, red: no installation allowed, yellow: installation based on case to case decision, green: no restrictions known)

Specific thermal capacity per surface area unit for borehole heat exchangers of a defined length.

Installations that enable the use of the energy stored underground in a depth of up to 300 to 400 meters