Your choices:
1 Fuel: solid; Biomass (solid); 2 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 | 2 Electricity |
| Biomass (solid) | Electricity | Process cooling (< 0 °C) |
| Geothermal | Fuel: Gaseous | Process heat/steam (50 - 150 °C) |
| Sunshine | Fuel: Liquid | Process heat (150 - 1000 °C) |
| Water | 1 Fuel: Solid | Process heat (> 1000 °C) |
| Wind | Local cooling (ind. house) | Transport |
| Residual oils/fats etc | Local heating (ind. house) |
In many cases, electricity is assumed to be the main energy carrier desired by the end users, but this is not necessarily true.
For the end user, the unique thing with electricity is its flexibility or, in thermodynamic terminology, its high share of exergy. Electricity can be converted into mechanical work, into illumination, into extremely high or low temperatures, into pressure, into radiation of different wavelengths; it can be used to run home electronics, for transportation and – basically – any number of applications. Because of the high quality and the high availability with electricity it should be priced accordingly and the use of it should be limited to such applications where the unique features are fully valued.
The high share of exergy in electricity means that the production from fuel firing is limited and this holds true for all types of solid-fuel fired electricity production plants. The side product is heat.
Since biomass is not mined the same way as coal and is not localised but has to be collected from a larger area involving logistics and transports, then biomass-fired energy production units will never be as large as coal-fired plants. This is an advantage, since it means that the amounts of heat produced are limited and the heat may therefore be sold and used to replace electricity in some applications. Thus solid biomass lends itself better for CHP-production than coal does, and electricity from solid biomass should always be produced in CHP-plants.
A significant share of the electricity produced within the European Federation is produced in coal-fired, condensing power plants. In these, pulverized fuel combustion is the most common technique and solid biofuel suitable for milling, such as non-durable pellets and briquettes or torrefied biomass, are well-suited to be used as a complementary fuel in such plants. Easiest, the biomass is milled together with coal and co-fired in pulverized coal power stations.
In many cases this may be the simplest and cheapest method to introduce biofuel into the national energy system. Experience from several types of plants and installations have for example been reported and documented by the International Energy Agency (IEA), clearly demonstrating the feasibility of this technology.