What Is the Ash Content of Wood Pellets?

Traditionally, the quality of wood pellets is classified according to their ash residues.

• Premium wood pellets have an ash content of less than 1%.
• Standard wood pellets have ash content between 1% and 2%.
• Industrial wood pellets have an ash content of over 3%.

ENplus certification standard

According to the standard of ENplus certification, wood pellets can be classified into 3 classes according to their ash content. They are divided into A1, A2, and B.

• The ash content of ENplus A1 level is less than 0.7%.
• The ash content of ENplus A2 level is lower than 1.5%.
• The ash content for ENplus B level is less than 3%.

An American NPO—Alliance for Green Heat, has carried out a test on 4 popular brands of wood pellets, including American Wood Fibers, Pennington, Curran Renewable Energy, Nation’s Choice, and Takoma Park Silo corn. Their ash content was relatively similar, ranging from 0.3-0.6%, which is lower than the ENplus A1 standard of 0.7%.