Over the past several decades, controlling wood pellet quality for foreign and domestic residential heating markets has been very challenging. For nearly as long as there have been residential wood pellet burning appliances, there has been the knowledge that not just any pellet will yield the best performance of the appliance. Wood pellet burning appliances require fuel that is very consistent in properties such as moisture content, density, and dimensions such as length and diameter to yield well-balanced combustion for a clean and consistent burn. In addition, the pellets must be low in fines and durable to prevent the creation of fines in handling. It is also critical that ash content be as low as possible to assure ease of maintenance and that the pellets are free of contaminants that can corrode the appliance.
Over the years, there have been numerous efforts to control the quality of wood pellets for residential use. In the U.S., the Pellet Fuels Institute developed its first standards in the early 1990s. Remnants of this original standard can still be seen today in the form of a guaranteed analysis block displayed on the bags of many manufacturers. This early standard provided guidance for properties such as moisture content, fines and ash. Several other countries also developed residential wood pellet standards between the late 1990s and the early 2000s. These include standards such as the Austrian Önorm, the German DIN and the Swedish Svenska standards. These early standards provided guidance for physical and chemical properties of the fuel, but they did not provide any guidance for quality management to achieve the standards and there was no enforcement of the standards.
By the early 2000s it became obvious that more was needed to control the quality of the wood pellet supply for the residential heating markets. As a result, various quality management schemes have now been developed that include very robust guidance on chemical and physical properties, quality management, and third-party enforcement. The quality management schemes currently available and their primary areas of use are as follows:
Established in 2002, DINplus was the first wood pellet quality scheme to enter the market. It was established by DIN Certco in Germany and gained much popularity in European heating markets. It was based on the German DIN wood pellet standards, which gave it a very regional emphasis, but has since adopted the European Union standards for wood pellets (EN 14961-2) and is now also referencing the newly developed ISO wood pellet standards (ISO 17225-2). DINplus is still used throughout Europe and Russia.
The PFI Standards Program was first published in 2008 as a voluntary consensus-based program, but was revised in 2011 for use within the U.S. EPA's residential wood heating standard. The PFI Standards Program has since become the primary quality management scheme used for the domestic heating market, as it covers about half of the wood pellets produced and sold within the U.S. for home heating. To date, the adoption of this program has been largely market driven, however, with the recent prepublishing of the EPA's updated New Source Performance Standard for Residential Wood Heaters, it is anticipated that the PFI Standards Program will be much more widely adopted within the U.S.
ENplus was established in 2011 as a collaborative effort by several European countries under the Pellcert project and is overseen by the European Pellet Council. ENplus is based on the European Union standard for wood pellets (EN 14961-2) and is anticipated to reference the newly developed ISO wood pellet standards (ISO 17225-2) with the next draft. ENplus is largely based on the needs of the European markets and now covers around 60 percent of the European production for residential heating. In addition, several U.S. producers have also certified to ENplus in order to sell production into the European residential heating markets.
Canada has also developed a wood pellet quality scheme called CANplus. The CANplus quality scheme is essentially the same as ENplus in that wood pellet producers first certify to ENplus and then apply to the Wood Pellet Association of Canada for CANplus certification. The primary difference between ENplus and CANplus is that the CANplus quality mark makes use of the Canadian red maple leaf. In addition, both ENplus and CANplus have also been referenced in the U.S. EPA's prepublished NSPS for Residential Wood Heaters making it possible for producers that rely on these quality management schemes to also gain recognition within the U.S. markets.
While controlling the quality of the residential heating wood pellet supply has been long in coming, we can finally rest assured that highly robust quality management schemes are finally in place. They have gained significant recognition within their intended markets and are now even supported by regulation, at least within the U.S. As such, all entities that operate in the wood pellet sector, both foreign and domestic can finally have a high level of confidence in the quality of fuel that will be available for their use provided they make use of the fuel produced under these various quality management schemes.