FAQ’s
What is woodfuel?
Woodfuel comes in three forms; logs, woodchip or Pellets. It is a clean, renewable energy source which has the potential to make a substantial contribution to the south west’s renewable energy target and have a positive impact on the climate. Forest Fuels supplies woodchip and logs.
How much woodfuel do I need?
The volume of fuel required for storage will depend on the daily heating energy required by the biomass boiler, the number of days storage required and the calorific value of woodfuel used. Storage volume should be at least twice the delivery volume. Consideration should be given to the size of delivery vehicles that can access the site and any limitations imposed on the frequency of deliveries.
How much does woodchip cost?
Typically woodchip costs in the region of 2.2 to 2.7 pence per kWh. However, there are a number of factors that affect price including method of delivery and fuel store design, which can amount to one third of the cost of the fuel. It is crucial this aspect is given careful consideration during the installation process as poor design will result in a potentially expensive delivery/storage solution for the life of the boiler ie 25 years.
A long term fuel supply contract will ensure continuity of supply, reliability and price stability.
When do I need to think about ordering woodchip?
We are constantly asked to supply woodchip at relatively short notice, for many dry fuel boilers (less than 35% moisture content) consumers need to be thinking about their fuel up to one year in advance. Timber needs at least one drying season to reach less than 35% moisture content. The larger the fuel demand the more notice required to source suitable fuel. Don’t leave it too late! A long term fuel supply contract will ensure continuity, security of supply and price stability.
How should woodchip be stored?
Woodchip is delivered to site in bulk transport. The unloading process is usually by gravity from a tipper or chain bedded truck. The fuel store is therefore usually at ground level or below ground, although pneumatic delivery is also a possibility.
Good fuel store design and planning how the delivery will be received are very important; one third of the fuel cost can be from a poorly designed fuel store and delivery method.
Why is moisture content critical?
Many boilers are designed to burn woodchip or logs with a maximum moisture content of 35% or less. The ideal moisture content is 20-25% - any less than this and the woodfuel will burn too fast. Although this can be achieved by air-drying wood, freshly cut ‘green’ timber and tree surgery wastes will be of much higher moisture content – typically 50-60% – which will cause many boilers to shut down. The simplest method of ensuring good quality, consistent supply is to find a reliable supplier.
Is woodchip size important?
The size and shape of woodchips is important to ensure the smooth running of the boiler. It is important that specialist woodfuel chippers are used, as general purpose wood chippers can produce long slivers which can lead to blockages in fuel feed systems.
Can I use tree surgery woodchip in my boiler?
Whilst this is possible, great care should be taken as you risk damaging the boiler. Green woodchip has a moisture content in excess of 50%, depending on the boiler design it may or may not be able to use this material. The main issue however is the energy value, modern boilers are highly efficient and therefore to optimise the number of kilowatt hours it is best to use fuel below 35% moisture content. Why invest in the best boiler technology and then fill it with poor quality fuel?
Is woodfuel clean?
Woodfuel presents no risk if accidentally released into the environment and there are no harmful by-products. The flue gas is smoke free and the ash content of between 0.5% and 1.5% by volume is minimal.
Why is wood as a fuel carbon neutral?
As it burns, wood produces carbon dioxide - one of the main greenhouse gases responsible for climate change. But this CO2 is absorbed by new growth. This means that no extra carbon is put into the atmosphere - which is why wood fuel is carbon neutral. Although, during processing more CO2 is released to the atmosphere, this is insignificant in comparison to other fuel types the 'embedded' energy in woodchip is negligible, much less than wood pellets.
Woodland in the UK is a renewable resource and therefore as trees are felled new trees are planted or re-grow as coppice. During the process of photosynthesis carbon is stored in the growing tree and the woodland soil. In the UK woodlands are managed in line with the UK Forest Standards and all felling is controlled by the Forestry Commission. The standards ensure that woodland is managed sustainably and to the best environmental standards.
Does using woodfuel for boilers damage woodland?
On the contrary, a demand for logs and woodchip creates a market for timber and wood residues that would otherwise go to landfill. It can help provide financial support to woodland management and can have a positive impact on flora and fauna, if managed correctly.
Every woodland has a sustainable yield, which can be harvested indefinitely without depleting supplies.
Where does Forest Fuels source its wood?
Forest Fuels supplies woodchip and logs from a series of depots around the south west, Cornwall, Devon, Dorset and Gloucestershire, each depot is fed from local timber resources and provides a market for under-utilised woodland resources. This means that local farmers, co-operatives, woodland management companies, sawmills, arboriculturalists, etc can all feed into the woodfuel market. Woodfuel is beginning to show its potential for unlocking the numerous under-managed woodlands of the south west and the consequent benefits to biodiversity.
Can woodfuel benefit the local economy?
A growing wood energy industry benefits the local economy because it generates income for owners, contractors, processors and suppliers. The increased forest management improves future productivity and asset value. Wood energy crops also have the potential to offer an important diversification opportunity for farmers.
Is there enough timber in the south west?
It is estimated that the woodlands of the south west have the sustainable capacity to produce 200,000 oven dry tonnes per annum of woodfuel. This equates to 4 million gigajoules of heat - enough for 50 - 60,000 homes - without impacting on exiting timber markets. There is also the recycled waste wood stream which has the potential to yield substantial volumes of woodfuel material.
For further information download the document below:
SW Woodfuel Framework.pdf
How many woodchip boilers have been installed in the south west?
South west England currently has about 10MW of biomass heat installed and 2.2MW of biomass plant generating electricity over some 30 projects. The recently launched bioheat programme administered by Regen SW will see a further 32 MW of installed capacity which will equate to around 40 new bioheat systems. Confidence in the sector is growing with every new installation.
See a map of renewable installations http://www.surveys.energysw.com
For further information on Woodfuel supply you can download the following guidance documents.
Woodfuel Supply Contract Options
Woodfuel Distribution and Handling
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