Your choices:
1 Process heat (> 1000 °C); 2 Electricity; 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 | Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | Electricity |
| Biomass (solid) | 2 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 | 1 Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
Sufficiently large-scale electricity production from biogas is scarce and should be contracted from CHP or tri-generation where biogas is one main contracted fuel. For the contract to really strengthen the company's green profile it will be important to really follow up all steps in the supply chain:
- The biogas producer will have to fulfil the criteria to make the digestate a valuable soil improvement agent containing not only nutrients and minerals but also organic carbon. Obviously, the quality of the digestate is strongly depending on the quality of the feedstock.
- The electricity producing plant will have to have an efficiency exceeding 90%, so only CHP or tri-generation plants will be of interest.
- The volume of contracted electricity must be sufficient.
Unless these criteria are fulfilled, the efforts to search for and contracting of electricity based on digestible sludge will not be worthwhile.