Your choice of boiler will dictate which fuel and vice versa, your fuel choice will dictate which type of boiler.
In general; domestic installations run on pellet, log or both, commercial boilers above 150 kW use wood chip, pellets or miscanthus (elephant grass)
Made from compacted sawdust, being a by-product from manufacturing; now mainly processed in the UK with an excellent network of distributors. Mainly used on fully automated boilers and can be delivered either in bulk or 10kG bags, requires dry storage as the moisture content needs to be kept below 10%. The larger the delivery the cheaper the fuel; consideration for this is important in the design stage. The largest delivery available at the moment is 20 ton which arrives in a 40ft HGV artic.
Woodland waste which is chipped, dried and stored, the moisture content can be higher than logs and pellets as the boilers are generally larger, having the ability to pre-dry the fuel in the burner box; larger storage than pellets is required. Chip boilers enable the use of cheap fuel with the added benefits of a fully automated operation; generally for the larger installation, 150kW plus, but units down as low as 20kW are available.
Usually sourced from own woodlands; requires drying to a 15-20% moisture content with an annual rotation for storage, along with manual input, (plenty of exercise without having to visit the gym) If logs are purchased it becomes less financially viable. Generally the largest log boiler Artizan installs is 60 kW anything larger and the man hours become a tie, requiring additional labour.
Ideal for farmer who can grow, harvest and store the fuel.
Harvested once late in the year, ready for use straight after harvesting. Suitable for larger boilers; with the ability to burn miscanthus.