Biomass boilers themselves can vary by as much as 40% for the same kilowatt output of boiler.
This is because of several factors, the first being the type of fuel you wish to use, if you were looking to burn a very wet fuel then you would normally require a fully stepped grate, which will cost more than a half stepped grate or underfed stoker, secondly the quality and quantity of materials used to make the boiler, as some models have considerable thicker steel and refractory linings, and thirdly the control functionality and software used to control the boilers can vary. As a general rule try and go for a mid ranged price boiler as this is most likely to offer the best value for money, these will generally be Austrian, Italian or Danish.
The system cost is very likely to out weigh the boiler cost and can make up to 80% of your total capital cost. The reasons for this, is completely dependent on the size of boiler / system required. A very small system will typically have a small fuel store (above ground) and can be connected almost directly into the heating system, where a larger system needing bulk delivery’s of fuel are likely to have a below ground fuel store and a district heating network connecting to multiple sub-plant rooms. Clearly any system utilising a below ground store and large district heating networks will involve a substantial civil element with large heating runs, this is likely to increase the cost of a project. However most large scale biomass systems lend them-self to large heat demands, therefore even though the cost can seem expensive the pay back period more than justifies the installation. Also as a general rule, the use of a district heating network will require more complicated controls, this is because of the delivery of heat to multiple buildings.