Hardwood pellets

What hardwood pellets are

Hardwood pellets are made from the wood of broadleaved trees — in Central Europe, among others, beech, oak, birch, hornbeam and poplar. As with softwood pellets, the standards do not treat them as a separate category. ENplus defines the permitted raw material by origin (stemwood, wood-processing residues and so on), not by species^[1], and the species is not a mandatory marking on the bag^[2].

In practice, the market offers both single-species pellets (e.g. beech) and pellets made from a mix of hardwood species or of hardwood and softwood — the latter are described in the article on mixed wood pellets.

Hardwood in figures

Two things are worth noting. First, FAO’s typical ash values for the wood itself are identical for both groups^[45], although the Finnish VTT measurements lead to the conclusion that hardwood species contain more ash than softwoods^[44]. Second, the difference in calorific value is a few per cent — less than is often assumed.

Advantages and limitations

Strengths

• Slightly less sulphur in stemwood than in softwoods according to VTT data (0.0090% versus 0.0116%)^[44] — although both values are far below the ENplus limit of 0.04%^[1].
• Availability of raw material in countries dominated by broadleaved forests — such as Slovakia and Hungary, which matters for security of supply.
• The ability to meet class A1 — with clean, debarked raw material and a well-run process.

What to watch out for

• Bark. Hardwood bark typically has approx. 5% ash, and in extreme cases as much as 10%^[45]. Even a small admixture can push the pellets beyond the A1 limit (0.70%)^[1].
• Nitrogen. Some hardwood species contain noticeably more of it than softwoods — VTT gives 0.19% for grey alder^[44]. This is still below the A1 limit (0.3%), but the margin is smaller. More on the significance of nitrogen on the chlorine, sulphur, nitrogen page.
• A slightly lower calorific value per kilogram of dry matter — a difference of a few per cent^[44].

Common beliefs

Where hardwood raw material comes from

The share of broadleaved trees in forests varies considerably between the countries of the region. In Slovakia, broadleaved species cover 65.2% of forests, and beech alone 35.8%^[50]. In Hungary, oaks cover approx. 32.7% and black locust approx. 24.6% of the forested area (editorial calculation from data in hectares)^[53]. In the Czech Republic, broadleaved species make up 45.1% of forests, including beech at 11.1%^[51], and in Germany beech covers 17% and oak 12% of the forest area^[57]. In Poland’s State Forests, the share of broadleaved stands rose from 13.0% in 1945 to 25.0% in 2024^[49].

Details for individual countries are in the wood pellets by country section, including the pages on Slovakia and Hungary.