Biomass Short for biological mass or all living things. Used as shorthand for wood biomass.

Energy units
There are many different units for measuring energy. For wood derived energy the kilowatt hour (kWh), the megajoule (MJ) and their multiples, are the principal units
Energy = power x time
Kilowatt = 1000 Watts or the equivalent of a one bar electric fire
Kilowatt hour (kWh) = the energy consumed by the one bar fire operating for sixty minutes
Joule = 1 Watt per second
Megajoule (MJ) 1 MJ = 1,000,000 Joules
1 kWh = 3.6 MJ
British thermal units (BTU) 3400 BTU = 1 kW

Thinning woodland The removal of a measured volume and number of trees to promote the growth and quality of the remaining crop.

Roundwood Timber in the form in which it was growing before any lengthways cutting has taken place. Usually applied to smaller diameter material.

Arboricultural arising's Branchwood and other material from street and amenity trees which have been trimmed. This material may be subject to the control of waste regulations and require a licence before it can be removed, check with the environment agency.

Slabwood Material from a sawmill produced when round logs are sawn into boards.

Recycled wood Timber which has already been used for some other purpose eg pallets. The wood must be free of contamination to avoid atmospheric pollution. It must also be without metal fastenings etc to avoid damage to the machinery.