Your choices:
1 Electricity; 2 Comfortable indoor climate; 3 Biomass (digestible sludge)
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| 3 Biomass (digestible sludge) | District cooling | 2 Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | 1 Electricity | Process cooling (< 0 °C) |
| 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) |
Electricity is the king of energy carriers and should not be used for low-exergy purposes such as indoor climate control.
In the case that biogas is produced at a single farm and, for example, burned in a local IC-engine producing 230 V single-phase electricity and house heating, then of course the generator should be connected to the internal house electricity grid. In that case, if the indoor climate control system includes also an AC-unit, the electricity will be used also for indoor climate control. That cannot be avoided, but in this special case, the indoor climate control is not the main purpose of electricity production.