Your choices:
1 Comfortable indoor climate; 2 Geothermal; 3 District cooling
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| Biomass (digestible sludge) | 3 District cooling | 1 Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | Electricity | Process cooling (< 0 °C) |
| 2 Geothermal | Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | Process heat (150 - 1000 °C) |
| Water | Fuel: Solid | Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
The use of cold water from the bedrock as free-cooling in a district cooling network would be an alternative to other sources of free-cooling like using the cold water from the bottom of a deep lake or a river but would require an un-confined aquifer with a sufficiently large through flow to be present underground. Chances for this are small and this cannot be considered a realistic alternative.
However: If the return water in the district cooling system holds a temperature higher than that which is obtained from the geothermal well – say that the return water holds 15 °C and the water from the well holds 10 °C – then the district cooling system could be used to re-charge the geothermal well during summer and hence improve the system performance during winter.