How we assess wood pellets

Our guiding principle

The certificate, country of origin, wood species and price all matter, but they are indirect indicators. What really tells you about pellet quality is the measured parameters of a specific batch — and whether the producer can keep them at that level from one delivery to the next. That is why every assessment we make starts with the same question: how do we know this figure is true?

Hierarchy of data sources

Every value on a product sheet is labelled with one of five statuses. We never mix them, and we never “average out” declarations and measurements.

We give the greatest weight to a result from an external laboratory that comes with full details: report number and date, name of the laboratory, test method (e.g. the ISO standard for the determination in question), sample basis (as received or dry basis) and who took the sample and when. A report supplied by the producer is valuable, but we note that the producer provided the sample.

Stages of assessment

1. Identification. Producer, plant, trade name, certificate number. We look up the ENplus number in the public register of certified companies^[3] and compare it with what is printed on the bag.
2. Documents. Product sheet, test reports and certificates covering the origin of the raw material (FSC, PEFC, SBP), where the producer holds them.
3. Sample assessment. Appearance of the pellets, length, dust in the bag, smell, condition of the packaging. This is an observation, not a measurement — and we describe it as such.
4. Laboratory analysis — where justified. If a product is commercially interesting and the available documentation is not sufficient, we may commission an analysis from an independent laboratory. We do not send every delivery to a lab — a value appears on the sheet as “independent analysis” only when we have the report.
5. Practical test. How the pellets behave in the burner: flame stability, the amount and structure of the ash, any clinker. The result depends on the boiler and its settings, so we always describe the test conditions.
6. Consistency. One good batch is not enough. In an ongoing working relationship we check whether subsequent deliveries match the agreed specification, and we compare the available results over time.

Class compliance and position within the class

A quality class (e.g. A1 under ENplus or ISO 17225-2) sets limits^[1],[11]. A result within the limit meets the requirement — yet products that differ markedly can all sit within the same class. That is why we assess on two levels:

• Compliance — whether every parameter is within the requirements of the declared class.
• Position within the class — how far the result lies from the limit. Ash at half the limit means, in practice, half as much ash to remove as ash right at the limit.

Price and quality

We will publish a value-for-money indicator only for products with a complete set of verified data. It will be based on the cost of the energy contained in the fuel (PLN per kWh, calculated from the price and the measured net calorific value as received), together with a description of the parameters that affect day-to-day use: ash, fines and the tendency to form clinker. We do not combine these into a single “magic” number without showing how it is derived.

What we do not do

• We do not publish rankings based solely on producers’ declarations.
• We do not accept payment for a place in a comparison or for a favourable description.
• We do not quote test results from reports we have not seen.
• We do not judge quality by the colour of the pellets or by the country of origin.
• We do not take credit for analyses carried out by others — we always name who performed them.

Conflict of interest

We are building a wood pellet sales channel, so in future some of the products we describe may come from our own offer. Those sheets will be clearly labelled, and the assessment rules will remain the same for every product — including those we do not sell.