Your choices:
1 Sunshine; 2 Electricity; 3 Electricity
| What is your resource? | What do you want to deliver? | What is the service the customer wants? |
| Biomass (digestible sludge) | District cooling | Comfortable indoor climate |
| Biomass (fermentable sludge) | District heating | 3 Electricity |
| Biomass (solid) | 2 Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| 1 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) |
Due to the low efficiency with commercial solar cells and to the "dilute" nature of solar radiation – except special conditions – the electricity produced from solar cell arrays is usually not near the demands for electricity in a modern building.
However: Solar cell arrays, with inverters to deliver onto the main grid, will always make a positive contribution to the over-all electricity balance and will be a part of the future energy system. There is also a growing market for "green electricity".
Though such installations are barely profitable today they may serve as positive examples.