As the largest source of renewable energy on Earth, it can be a major player in climate change policies.
A number of people contacted me following last month’s article, wondering why I didn’t mention wood pellets or wood chip as a renewable fuel source.
Last month’s article focused on the efficient production of firewood from young broadleaf woodlands.
Timely first and second thinnings provide the better quality trees with more space for vigorous growth, allowing for the production of more valuable hardwood sawlog. The production of (fire-) wood from early thinning operations is a by-product of good management. The firewood market, together with support from the DAFM thinning grants, is a very important enabler to broadleaf management and allows forest owners the chance of some additional income.
All wood-fuel types — such as firewood, wood pellets and wood chip — will have an important role to play over the coming decades.
Wood fuel can displace fossil fuels for residential, commercial and industrial heating, thereby contributing to climate change mitigation policies.
On a global level, wood fuel remains by far the largest source of renewable energy.
Wood fuels are increasingly becoming more tightly specified and new technologies to use wood for heating are constantly developing.
Firewood, wood chip and wood pellets are all excellent wood-fuel options. Each has their own advantages and disadvantages.
Wood Fuel Types
Wood pellets are made from compressed sawdust in an industrial process and are usually derived from conifer timber.
Pellets are more expensive to buy, but more compact, easier to handle and have a low moisture content.
Wood chips can be produced and handled locally without additional processing costs. They are suitable for heating larger premises where space for storing is available.
Once cut, the wood needs to dry out very well before chipping takes place. Chipping green wood attracts lower prices and requires additional drying facilities. Chipping may take place either in the forest, at roadside or at the final destination.
Storage space needs to be taken into account when deciding on a wood-fuel heating system.
For instance, 1,000 litres of home heating oil has a volume of about 1.5 cubic metres. Wood pellets replacing 1,000 litres of oil will require double this storage space; firewood logs four times this volume, while wood chip will take up eight times the space.
Although I am repeating myself, it is a critically important point to make — don’t be tempted to burn wet wood.
It is bad for your health, bad for your pocket and bad for the environment.
New Publication
Wood As A Fuel is a new comprehensive publication describing all aspects of wood fuels, from basic wood properties to standards, to wood-fuel types, combustion and sustainable use.
It consists of five volumes, which describe the main wood fuels: firewood, wood chip and wood pellets. They outline raw material sources, seasoning, drying and production processes, transportation and quality issues.
Many examples of ways to improve product quality and efficiency are provided, and are designed to enable readers to produce and use high quality wood fuels.
The history of wood fuels, an outline of what wood is and why it makes such a useful and versatile fuel are covered in the opening volume.
Standards, the backbone of wood-fuel trade, are outlined. Trade itself and other relevant aspects of transacting wood fuel round out the introductory volume.
The final concluding volume comprises two parts. Combustion, wood ash and embedded energy are covered in the first, while the second part deals with economic and sustainability aspects of wood fuels, including one of the main rationales for their use — tackling the climate emergency.
Other topics covered include sustainable harvesting and how modern bioenergy use leads to clean combustion.
This publication is written by Pieter Kofman and Eugene Hendrick and can be ordered from arrowmanagement.ie.
Steven Meyen is a Teagasc forestry advisor based in Ballybofey; steven.meyen@teagasc.ie.
(Source – Irish Independent – Indo Farming – Steven Meyen – 02/11/2021)