Wood energy
Wood energy is the use of wood fuel to produce heat or electricity. Wood fuel is a sustainable, carbon-neutral fuel and offers a real opportunity for New Zealand to become greener and less dependent on fossil fuels. Wood fuel is any source of wood or herbaceous biomass (biological material derived from living, or recently living organisms). Wood biomass is the main source of wood energy in New Zealand. It comes in a number of forms, including firewood, shavings, sawdust, wood chips, agricultural crops and bark.
New Zealand has fast plant growing conditions and a successful forestry sector. Until recently, forest and wood processing residues were considered waste. Using wood that would otherwise go to waste as a resource delivers numerous benefits, including providing additional revenue streams for forestry and land owners.
New Zealand has a thriving wood fuel sector, with expertise in the production and sale of all types of wood fuel and the heat plant equipment in which to use them.
Wood chip for fuel can be sourced from forest harvest or wood processing residues. There are different grades of wood fuel which need to be matched to heat plant design for efficient operation. Bioenergy Association-accredited wood fuel suppliers supply consistently-graded fuels.
Heat plant feasibility studies should be only undertaken by Bioenergy Association-registered wood energy advisers because of their expertise in balancing fuel type and grade and equipment design.
Wood pellets are a high-quality form of wood fuel. They are small, cylindrical pellets made from wood waste, such as wood shavings and sawdust. They are shredded and then compressed under high pressure and wood’s natural glue – lignin – acts as a binding agent to hold the pellets together.
Residential pellet stoves are easily installed and the resulting emissions are so low they can be burned even in areas with burning restrictions. They have a near total combustion and their efficiency rating can be as high as 94 percent. Typically a wood pellet burner has a large hopper and can burn continuously for several days.
The wood pellet market is an established and growing sector in New Zealand, with a number of producers of fuel and providers of residential and industrial equipment. The market includes small-to-medium commercial operations.
More information on wood fuels, including wood pellets is available on the www.usewoodfuel.org.nz website.