Your choices:
1 Process heat (150 - 1000 °C); 2 Fuel: gaseous; 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) | Electricity | Process cooling (< 0 °C) |
| Geothermal | 2 Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | 1 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) |
Because of the availability and reliability of the gas supply, combined with the ease of control inherent with gas combustion, direct gas firing is often used in industrial applications. As long as the gas quality and the quality of the delivery remain constant, the real origin of the gas will make no difference to the end user. Contracting a delivery of biogas is therefore one of the simplest ways to render the industrial process classify as operated on a renewable energy resource.