Your choices:
1 Water; 2 Process heat; 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 | Electricity |
| Biomass (solid) | 3 Electricity | 2 Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | 2 Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | 2 Process heat (150 - 1000 °C) |
| 1 Water | Fuel: Solid | 2 Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
By aid of electricity – the king of the energy carriers – any temperature ranging from cryogenic up to more than 3000 °C can be produced. Electrical processes are also simple to control and they are "clean" – as long as one does not take into account the emissions caused during the production of the electricity itself.
Hence; many industrial processes and customers prefer to buy electricity for their processes, though this may, from a thermodynamical point of view, not be the optimal choice.
For electricity to be the best choice, the production must have been clean and it must exhibit the highest possible efficiency. There is only one energy source that can provide efficiencies exceeding 95% and – if properly designed and operated – no environmental harm, and that is hydropower production of electricity.