Pellets: A Sustainable Fuel for theThird Millennium
The first wood pellets appeared in Switzerland in the late 1990s. They quickly gained popularity as a supplement to firewood and wood chips.
Two major advantages over “traditional” product lines:
- High energy density: about 2× that of logs and 4× that of wood chips. A furnace that used to burn 2,000 liters of fuel oil per year now needs, with a pellet heating system, only about twice as much storage space as before—which is generally feasible.
- A raw material that’s “already there”: initially, the pellets came exclusively from sawmill and planing mill residues (sawdust, shavings, wood chips). “Waste” that has become a high-quality energy source.
Unsurprisingly, the first pellet heating systems were installed mainly in single-family homes. Pellet heating thus introduced wood-based energy to a younger, urban audience with fewer ties to the forest.
Please note: In Switzerland, pellets made from forest wood and agricultural biomass are still rare. Residues from secondary processing (carpentry, furniture) are not permitted, as they are no longer in their natural state.
Two markets that don’t communicate with each other
1998–2023:
- The number of pellet heaters (including stoves) has increased from 172 to 32,367.
- Annual consumption has risen from 850 metric tons to nearly 430,000 metric tons, with an estimated 550,000 metric tons by 2027.
Their use extends far beyond single-family homes to include apartment buildings, housing developments, hotels, and tourist complexes. The reasons: they take up less space, and the air-injection feeding system is simpler than that used with wood chips. This high demand raises questions about the security of the supply of pellets and raw materials.
Order of magnitude for raw materials:
- Sawing 1,000m³ of roundwood produces approximately 90 metric tons of sawdust and wood chips, plus 110 metric tons of wood chips → a theoretical potential of 200 metric tons of pellets.
- 2007: 2.4 millioncubic meters of sawn lumber → approx. 480,000 metric tons of potential.
- 2023: 2.0 Mm3 of sawn lumber → approx. 400,000 metric tons of potential, which is less than actual consumption.
These figures are theoretical: many sawmills use their own waste (for drying and district heating) or send it to their pellet plants. The particleboard industry is also a major consumer. As a result, annual pellet imports have hovered around 100,000 metric tons for years. Imports of sawdust and wood chips for pellet production, however, are difficult to quantify.
Key point: Sawmills are not increasing their sawing output because demand for pellets is rising. Sawmill output is primarily driven by conditions in the construction sector, both in Switzerland and internationally. The two markets are decoupled. What was long considered an advantage (“the raw material is available anyway”) is now becoming a limitation.
New raw materials, new concepts
In 2022, Switzerland and much of Europe feared supply shortages of wood fuel, particularly pellets. Some countries raised the possibility of halting exports in the event of a crisis. The crisis was averted, largely thanks to the mild winter.
Everything points, however, to a continued rise in demand. For environmental and energy policy reasons, the goal is not to respond solely with more imports (pellets or raw materials). Local sourcing and the circular economy remain decisive factors; otherwise, we might as well import oil or gas.
Observation: Centralized sources of raw materials for pellets are already being extensively exploited. The logical next step is to examine decentralized resources from forestry and agriculture.
With thePROXIFLEX mobile pelletizing plant, a proven technical solution enables production to keep pace with these decentralized resources. The result: short transport distances and an excellent environmental footprint.
by Andreas Keel, March 16, 2025
