Harvesting, processing and burning woodchip for heat
Choosing a biomass fuel source can be a daunting affair as there is a seemingly endless list of 'considerations'. Here we discuss using home produced woodchip as a fuel source for a biomass boiler.
At any scale of operation, does it make commercial sense to invest in your own harvesting equipment, storage facilities, handling equipment, maintenance, insurance, labour, training and HSE? Is it be more cost effective to employ third party contractors for either the whole of the harvesting, extracting and chipping process or perhaps just one or more part of the process? It is hard work and the kit is expensive to buy and maintain. No one will argue with you that these are not the ultimate 'boys toys' but can you really justify the capital and operating costs that go with them?
Woodchip specification and standards
For the efficient operation of any automated boiler it is important that a consistent size and quality of woodfuel is achieved. To ensure that your wood chip meets the required standard (in terms of size, quality and moisture content) for the boiler/burner, a simple common standard (CEN/TC 335 biomass standards) for end users is employed such that each batch of home produce or bought in chip will be of a consistent quality; not only for trouble free boiler operation but also to allow a much more accurate assessment of the amount of woodfuel you will need to produce the required heat and power. Wood chip particle size and moisture content being the critical considerations for self producing operations.
It is not really within the remit of the boiler manufacturers to consider in depth the logistics for clients wishing to process and use their own fuel but that does not mean it is any the less important. The challenge is to process a growing tree ( average moisture content of 55%) and process it to be an acceptable size, shape and dryness to be efficiently loaded and burnt by the boiler.
Logs, briquettes, pellets and wood chip are the most popular fuel options for biomass boilers however there are only a few boiler manufacturers that have dual fuel options.
Generally most boiler manufacturers will offer pellet burning boilers as a preference to wood chip, but in many instances we find smaller to mid sized operations (estates, tree surgeons, wood mills etc) where self-produced wood chip is a preferred and sustainable option.