Wood Fuel Quality

All woodfuels produced from Forest Energy first thinning sites were characterized for moisture content, ash content and gross calorific value. Wood chip was also tested for bulk density and particle size distribution. Sampling, sample preparation and test methods were all carried out according to CEN Solid Biofuel technical specifications.

Bulk density of wood chip, measured in kg/m3, is an important parameter, as energy content is quantified by weight, whereas the transportation and storage of wood chip is generally limited by volume, as wood chip is a relatively low density fuel compared with fossil fuel. Bulk density is determined by the basic density of wood, moisture content and mean and range of particle sizes produced by the chipper.

The two critical variables for estimating the energy content of wood fuel are weight and moisture content. Where it is neither possible nor practical to measure weight and moisture content directly, the bulk density could be estimated easily by sampling and the total load weight be derived from the load volume and estimated bulk density. The moisture content could be estimated from a fixed relationship with bulk density described for individual species and assortments. Delivered energy content could then be estimated from load weight and moisture content estimates. There are obviously large potential errors associated with this method, but in the absence of a more accurate approach, it could facilitate trade in wood chip for energy purposes.

Wood fuel database

This database was developed by the Waterford Institute of Technology to provide industry, researchers and interested organisations with information on the biomass properties of tree species growing in Ireland.

The information that populates the database was collected from the felling and destructive sampling of specimen trees. It is presented in an online web-based format, where users can query parameters to view specific data as graphics, download figures, and also tables of the underlying data, which is all freely available.

Wood fuel database

Fuel profiles

This page provides summary information about the characterisation and quantification of the various fuels produced by the wood fuel supply chains described in this website. Profiled characteristics include calorific values, bulk volumes, particle size distributions, ash content and bulk density.

This data should be useful to any parties involved in the trade of woodfuel.

Fuel Profiles

Firewood storage trial

The Forestry Research group at Waterford Institute of Technology established a firewood storage trial in June 2013 at the Carriganore West Campus of Waterford Institute of Technology. The main purpose of the firewood trial was to investigate the following:

  • The drying rates of Sitka spruce firewood outdoors, under Irish climatic conditions and to compare the drying rates of each firewood product.
  • To determine the bulk volume of the various firewood products to give an indication of how much space is needed for firewood storage.
  • To describe the types of waste produced during firewood processing and to quantify each type of waste.

Firewood storage trial

Standards and equipment

The Forest Energy Programme has the use of dedicated forestry research and laboratory equipment located at the Waterford Institute of Technology. The facilities are split between a laboratory in the Cork Road Campus, and extensive workshop space in the West Campus at Carriganore. This page contains a list of all quality tests performed, and the equipment currently used.

Standards and equipment

Further reading