Micaul Solar Biomass Boilers

Definition of Biomass versus Fossil Fuels

Biomass is material derived from living, or recently living organisms, as an energy source can be plant,

vegetable and animal energy and can include wood, food, industrial and agricultural waste and certain crops

which can be grown purposely for energy use.

Although the definition of fossil fuels is very similar to biomass, the critical difference between them is that

fossil fuels such as coal, gas and oil are made up biological material that absorbed CO² millions or year ago

and when burnt release this previously stored into the atmosphere today. Biomass on the other hand has taken

carbon out of the atmosphere whilst growing and releases it when burnt all within a much shorter and manageable

timeframe with no overall increase in CO² levels over this shorter period.

Wood Pellet Boilers

Many wood pellet boilers are now as automated and controllable as an oil boiler and with pellet transfer from

storage to the burner via vacuum or auger arrangement, the pellets are delivered on a automated heating and

hot water demand cycle. The burner itself can also be lit and extinguished when required.

Wood pellets are made from sawn timber which is crushed into pellets with maximum length 25mm and usually

about 6mm to 8mm diameter, with moisture level less than 10%. The resin lignin which is inherent in the wood

hold wood pellets together requiring no additional materials to bind the pellets.

The quality of the wood pellet is critical from its density and ability to be transported without breakdown to its

material content. Issues over the past years with non virgin wood with chemical additives being used to create

pellets has caused feed and very costly combustion problems that have resulted in burner and flue failures.

Costs of pellets vary from about £120 per tonne upwards and are usually dependent upon contractual commitment

with respect to supply volume and period, transportation costs and local storage capacity. The greater the local

storage capacity the cheaper per tonne the cost tends to be.

If space is limited within the building, some wood pellet systems can be supplied in the form of a pre-fabricated

external plant room.

Log Gasification Boilers

If logs are readily available and accessible, a log boiler can be used to either provide direct heat (via appropriate

vents and safety systems) to the heating and hot water or more usually these are now used as a source for

‘charging’ an accumulator or large thermal store. This charging or heating and storage of a large body of heated

water will enable the water to be used over a period of time to provide the heating and hot water directly from the

store. The disadvantages of using a log boiler are primarily availability and storage of logs and the manual operation

required to feed, run and clean the boiler.

When used as part of a multi-energy source heating system, a log boiler can provide a very useful and additional

heat source.

Biomass Boilers with Solar Thermal

When Biomass boilers are used in conjunction with solar thermal systems, reductions in energy and carbon

emissions are even greater. Although the operating costs of the biomass system are much less than other systems,

solar thermal operating costs are almost negligible, usually only the cost of running a central heating size pump.

Solar PV panels cans be used to power a DC pump and controller which will eliminate this cost.

To find out more, contact us on  01633 53 54 55