What exactly constitutes energy wood?

When most people hear energy wood, they think of log fires and increasingly today of pellets, but energy wood comes in many guises. And therein lies the problem. 

In Switzerland, energy wood is officially classed as either: natural wood (divided into logs and woodchips) or wood residues or reclaimed wood or wood pellets. It could however be argued that all these types of energy wood are “natural” (and not just logs and woodchips), because all of them originally came from trees. 

Indeed, wood residues consist largely of the sawdust and shavings left over after wood has been processed into timber. Although wood residues are very versatile and can be transformed into insulation, paper and particle boards for example, many smaller sawmills simply burn them to heat their own premises.

Reclaimed wood constitutes unwanted wood from the furniture, packaging and building trades. It is increasingly being used in large waste burning plants in what is termed the “optimised cascade”. This is just a fancy way of saying that wood should first be used as a material before being burnt, but burning treated, varnished and painted wood results in highly toxic emissions and ash.

As for wood pellets, they are currently made both from “wood residues” and “natural wood”, so why have a separate category? 

Another term much used by officials and proponents of the biomass industry is “waste wood”. They claim to burn mostly waste wood, but while this definition is key, it is not clear cut. As we have seen, those benefiting from burning wood may have a very different definition of waste wood than a nature organisation or a manufacturer of particle boards, for example. 

And do you really believe that up to half of all silvicultural interventions consist of “waste” or “inferior” wood? Well, this is what officials claim but again it is a question of definition. 

It is also a question of logistics. Switzerland’s 292 sawmills specialise in conifers and only process around 4.3% of hardwood, hence why “At present, a disproportionately large proportion of high quality beechwood has to be used to generate energy or is exported at low prices to Italy and Asia”, according to Switzerland’s 2022 Market Statement to the UNECE. 

In 2022, 74% of all logged domestic hardwood was burnt. Do you really think it was all “waste” wood? Do these beech trunks look “inferior” to you?

 All these whole trunks, mostly of old beech wood cut in the Jura were chipped in 2023