A biomass boiler works in a very similar way to conventional boilers, combusting the fuel to produce heat that is then used to heat water. Biomass boilers are normally substantially bigger than their fossil fuel burning brothers though for a number of reasons. Firstly since they are burning the wood pellets as opposed to gas, the boiler needs to be larger to hold the larger volume of fuel.
In addition, you may wish to install an auto feed hopper on your biomass boiler, which will require additional room. This hopper stores a large volume of the wood pellets that are then automatically fed into the boiler as required, meaning that the boiler needs to be refueled very infrequently.
It is also a good idea to have a store of the wood pellets on your property so you can keep producing heat if for some reason there is an issue with your fuel supplier. Ideally this should be close to where the fuel is delivered to your home to minimize the distance you have to carry it.
Most residential biomass boilers can also run on logs as well as the wood chips, so if these are in plentiful supply or if you can source them cheaply or even for free, it will dramatically reduce the operational running cost of your biomass boiler.
Every four weeks or so, the biomass boiler will need to be emptied of the ash, but this can be put straight onto a compost heap, which will help fertilize the soil.
Biomass boilers are designed to work all year round, however you may choose to turn them off in the summer, so they can be coupled with solar heating or an electric shower, providing you with your hot water for washing only, during the warmer summer months.