Wood chips: still unbeatable in industrial heating
If we had to give just a single number as to why more and more plants are heating with wood chips, it would be this: the cost projected on useful heat is typically a half to a third of that of piped gas. This ratio has sometimes narrowed and sometimes widened over the past ten years, but the order has never reversed.
Wood chips are, moreover, a local product. They are generated as a by-product of forestry, sawmills, and logging, which is why their price primarily depends on the transport distance, not on the world market. Anyone who finds a stable supplier within a radius of thirty to forty kilometers can calculate years in advance.
What kind of boiler is suitable for wood chips?
The heart of wood chip firing is automatic feeding: the conveyor screw or the spring-loaded extractor continuously delivers the fuel from the storage to the combustion chamber, and the boiler automatically maintains the set output. The Fröling Turbomat, KWB Multifire or Hargassner machines, which regularly pass through our warehouse, have been the benchmarks in this category for decades.
The good news is that these boilers are exceptionally long-lived. A twenty-year-old, well-maintained Austrian wood chip boiler was built with a thick steel heat exchanger and a robust feeder, and after refurbishment, it will serve for many more years. This is precisely why it is worth buying used: hardly anything is lost from the useful lifespan, but all the more from the price.
Storage must be planned for
The biggest disadvantage of wood chips is their space requirement. For the same amount of heat, roughly three times the storage volume is needed compared to pellets, which is why a wood chip system is only worth planning where there is space: agricultural sites, industrial yards, timber yards.
Quality is also important: wet wood chips contaminated with soil reduce efficiency and increase maintenance requirements. When signing a contract, always specify the moisture content and particle size; material of class G30-G50 with a moisture content below 25-35 percent is ideal for most industrial boilers.
In our warehouse, several types of wood chip boilers between 20 and 500 kW can be viewed. We are also happy to help you find which design best suits your site and the available wood chips.