FAQs - on wood energy use
Q: Why should my school or business use wood energy?
The use of wood energy can be an attractive option as it can provide economic and environmental benefits to your school or business and to New Zealand as a whole. Find out more about the economic and environmental benefits of using wood as energy.
Q: What are the environmental impacts of burning wood as fuel?
Unlike most electricity and fossil fuels, wood is a clean, efficient and renewable source of energy which has little or no negative impact on the environment. Although wood releases carbon when it is burned, this is off-set by the carbon which is absorbed when a tree is grown. Find out more on the environmental benefits of using wood energy page.
Q: Can I convert our existing heating system to use wood energy?
In many cases the answer is yes! Find out more on the wood fuel options for schools and commercial buildings page.
Q: What is the wood supply situation in my area?
New Zealand has an abundant wood fuel supply that for the foreseeable future will outstrip demand. For a national overview of supply, more information can be found in the New Zealand Biomass Resource Atlas.
Several feasibility studies have looked at regional supply in more detail. The areas looked at include:
Q: How much energy can I get from wood?
Wood can be converted into a number of different fuel and energy forms. The values in the table below provide broad estimates of the energy which could be created.
One cubic metre of solid Pinus radiata wood at 50% m.c (wet basis) could create:
|Heat||6.6 GJ @ 80% eff|
|Electricity||1.64GJ or 455kWh @ 20% eff|
|Heat & Electricity via CHP1||5.7 GJ heat (60% eff) and 228 kWh electricity (10% eff)|
|Biodiesel (31 MJ/l)||100 (90 to 106) litres*|
|Ethanol (24 MJ/l)||148 (140 to 152) litres*|
|Bio-oil (21 MJ/l)||300 (270 to 330) litres*|
|Wood gas (5MJ/m³)||1130m³ (requires drying to 15% m.c. wet basis)|
*assumes 1 cubic metre contains 0.440 oven-dry tonnes of wood
In comparison diesel has a calorific value of 39 MJ/l and natural gas is 36MJ/m3.