Your choices so far:
1 Process heat (150 - 1000 °C)
| 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) | Electricity | Process cooling (< 0 °C) |
| Geothermal | 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) |
Many industrial processes, like the melting and production of secondary aluminium, paper- and pulp production, several chemical processes, extraction of metals from scrap and electronics and alike, require temperatures exceeding those that can be supplied by district heating. At the same time, the temperature demands may well be modest enough to be supplied using fairly simple fuels and to maximise the over-all efficiency and hence conserve natural resources the shortest possible chain from energy resource to energy service should be strived for.
Obviously, electricity can be used to provide modest temperatures and it is sometimes the preferred choice since it is simple to control, for example in secondary aluminium production, but from a thermodynamic perspective this is not optimal. If electricity is used, then it should originate from hydropower, from wind power or from a solid-biomass-fired CHP or tri-generation plant.
Another option is direct fuel firing using gaseous or liquid fuel. Both gaseous and liquid fuel can be produced from renewables, but the liquid fuel qualities, ethanol and FAME, will mainly find their market with the transport sector where the willingness to pay is the highest. Hence the liquid fuels will be excluded here. For gaseous fuel, the prerequisite from the end-user will be that the fuel is readily available and hence only such qualities that are made available through the European gas grid will be of interest. So this is upgraded biogas from anaerobic digestion.
Solid fuel firing may – for some processes – be an attractive alternative.
Hence the energy carrier should be selected with respect to the energy service desired but electricity is often the preferred choice because it is easy to control and it is clean at the end user. If the electricity was also produced in a hydropower station, NB a hydropower station where thorough environmental concerns have been taken, then the environmental impact through the whole production chain is minimised.