Your choices:
1 Electricity; 2 Biomass (solid); 3 Comfortable indoor climate
What is your resource? | What do you want to deliver? | What is the service the customer wants? |
Biomass (digestible sludge) | District cooling | 3 Comfortable indoor climate |
Biomass (fermentable sludge) | District heating | Electricity |
2 Biomass (solid) | 1 Electricity | Process cooling (< 0 °C) |
Geothermal | Fuel: Gaseous | 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) |
In case electricity is produced using solid biomass as the main resource and this is done using modern technique then there will also be district heating available, district heating that has to be sold since the sale of the heat will be the limiting factor for the amount of electricity that can be produced.
The district heat is then what shall be offered to the end-users for climate control, not the electricity.
- Central heating in single-family houses can be water-borne which is preferred in case of district heating or it may be air-borne. In case of water-borne heating, the production of tap water is normally integrated in the same heat exchanger as for the production of radiator water but of course with a separate heat exchanger coil.
- Though an apartment house in itself constitutes a number of households is the peak need for heat not necessarily equal to the sum of the peak need for heat in the individual households. The reason for this is that chances are that the peak loads in the individual households occur at different times. Even if the individual households do not have their morning shower at exactly the same time will they all have their showers at about the same hour of the day.
- Office buildings will quite frequently have a pronounced need for cooling during office hours because of the excess heat delivered by office electronics and by the fact that the number of persons per m2 in an office building is usually more than the number of people per m2 in homes.
- Shopping centres, sports centres, schools, hospitals, official buildings and such, aimed to host a large number of people of varying ages and constitutions and not primarily a cadre of sitting middle-aged people, will again pose new demands on the indoor climate control.
Electricity is the king of energy carriers and should generally not be used for indoor climate control.
However, it often is and in warmer climates this takes place using air-conditioning units and electrical water heaters for the production of tap water.
In densely populated areas such as cities and larger communities, and from strict efficiency and thermodynamic standpoints, this is an un-economic use of exergy and ought to be replaced by district heating and -cooling systems based on CHP-production so as to free the electricity now used for climate control for other purposes and at the same time increase the electricity production capacity.