Use energy in wood crops or animal waste
Biomass is organic material that can be used as an energy source. Fuelling your business with solid biomass such as wood is a great opportunity for your brand and a safe bet for your business. Fossil fuel prices are more volatile than locally-sourced biomass and investment in fossil-fuelled equipment is becoming riskier.
Wood energy is a by-product of New Zealand forestry. It's low carbon because trees absorb carbon as they grow, offsetting the carbon that's released when wood is burned.
Establish a long-term relationship with local biomass suppliers for long-term certainty and protection from future carbon-related costs.
Is solid biomass right for your business?
- Temperature requirements above 100°C
- Mostly continuous energy needs for long periods of time
- Space available for storage
- Capacity to receive regular delivery trucks.
Wood pelletsDried and compressed sawdust and shavings from sawmills. They produce heat quickly, are easy to store and handle and burn very cleanly. They are more expensive per unit of energy than wood residue and need a specific type of burner to be most efficient. Available in sizes from 10kg bags to truckloads.
Wood residueUsually wood chips but can also be shavings, sawdust or bigger pieces (hog or slab wood). Wood chips are available all over New Zealand, are relatively cheap and burn efficiently at moisture levels of up to 55%.
Which type is best for you?
If biomass such as wood energy is available in your area, the next things to consider are:
- Fuel storage capacity. Wood pellets provide more energy per unit volume than wood residues
- Energy profile. If your energy needs vary a lot during the day, wood pellets burners offer more flexibility than wood chips.
- Boiler capability. If you want to convert an existing boiler, its design will dictate the type of biomass you can use.
- Wood fuel burning technology. It’s important to know what fuel specifications your combustion unit needs to optimise its capacity and efficiency.
If you need only space heating and/or hot water, a heat pump might be a better option. They’re fuelled by our 80% renewable electricity, can deliver temperatures above 90°C and are much more efficient than a boiler.
Converting to solid biomass
Some heating systems can be modified to use wood energy.
Coal burners. These are relatively easy to convert. You’ll need to build a steel bunker and feed system, then adjust the combustion characteristics. You may need to add safety features as well.
Gas and oil burners. You’ll need to change the combustion head and plan for the additional storage requirements of wood fuel.
Installing a new boiler
If you opt for a new boiler, you can still use the existing heating network. This is a particularly viable option if your existing boiler is due for full replacement.
Wood pellet boilers are specifically designed to burn pellets efficiently. The wood pellets are fed in automatically and the feed rate varies with the required heat output. Wood pellet fuel is very consistent in quality so a pellet fire can adjust the air to match the fuel, making sure that the wood is completely combusted even on low settings.
Wood chip boilers vary in their combustion and feed mechanisms. Most new ones are fully automated. Wood chip boilers use heat exchange surfaces to heat water so they’re a good option for hot water and steam heating systems and for large users of heat, such as hospitals, hotels and universities.
Agricultural residues boilers able to burn light forms of solid biomass (such as straw) are commonly used around the world for medium to large-scale operations.
Find out more
Bioenergy Association(external link) Visit the WoodEnergy portal to find experts, suppliers and case studies.
Wood Energy South(external link) Case studies on wood fuel in schools and commercial businesses.
Scion(external link) Crown Research Institute focused on forestry, wood and other biomaterial.