Your choices so far:
1 District heating; 2 Process heat
| 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) | 1 District heating | Electricity |
| Biomass (solid) | Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | 2 Process heat/steam (50 - 150 °C) |
| 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) |
District heating may be provided in the form of hot water (most common) or steam. These media will set temperature limits so that hot water can usually not be supplied at temperatures exceeding 120 °C and steam is not commonly delivered at temperatures exceeding roughly 250 °C because of the losses inherent in the distribution system.
However, many industrial sectors such as the paper-and-pulp sector, food manufacturing industries, saw-mills, joineries and furniture manufacturers, greenhouses and many other will have a pronounced need for heat supply below the temperatures available with district heating systems.
The advantage for the individual company is that outsourcing the heat production to a specialised energy production company they may concentrate on their primary business idea and trust that the energy needed for the process is there at any instant. At the same time, the advantage for the energy utility is that industrial customers will provide for a stable base load, increasing the total energy turnover and scale of the system and maybe make electricity production feasible.
Hence: Whenever a biomass fired district heating system seems to be a suitable alternative, the planning stage should also include a thorough investigation of the process heat demands within reach of the system and the final system layout may very well become strongly dependant on the industrial needs in the area – rather than on the distribution of residential areas.
For the customer one main advantage with district cooling as compared to individual cooling is that the responsibility is handed over to a central, large-scale, production plant with 24-hour manning and professional personnel. Thus, the risk for breakages and the risk that the central AC-unit must suddenly be replaced at a high cost is minimised. The price paid is, of course, a fixed fee.