Wellington
Foresters in general and farm foresters in particular have a much more valuable resource thanjust the logs or lumber.
Forest harvest contractors too could make more money by regarding the total tree, especially whatis now left to rot, as a multi-product supply.
"We're getting to a stage now where greater volumes of biomass is required for bioenergyactivities," says Bioenergy Association of NZ ExecutiveDirector Brian Cox.
"Using wood waste onsite, as in a sawmill has been economic for a decade. It's now becomingeconomic to buy in such products from forest harvest residues and purpose grown short rotationcrops."
Cox gives the examples of wood chips and reformed wood pellets being used directly as a heatsource, replacing coal in furnaces. The same chips or pellets can also be burned in a gasifier(retrofitted to an existing gas boiler) and used to replace natural gas .
However, this requires an understanding the science of combustion of biomass, under differentpressures, temperatures and amounts of air so that it can be utilised for its solid, liquid and gascharacteristics - and sometimes a combination of them.
By using lignocellulose from trees and short rotation crops such as willows to make bioethanol orbiodiesel, and extract the other 'good bits' for use in new biomaterials, landowners have newpotential income streams. Cox says it will take 10-15 years to develop commercial plant to makebioethanol or biodiesel from such sources, but that people should be planning for it now.Internationally pilot plants are being built and this is the last stage before full commercialinvestment.
He is a strong advocate that energy crops will be complementary to traditional land uses. Hegives an example of kiwifruit growers, whose 10ha property may only have 6ha of crop. The other 4hacould be planted in Miscanthus (atype of woody grass), and cropped annually as a feedstock for ethanol production.
Cereal growers in South Canterbury are doing a similar thing now with regard to growing rapeseedfor the production of oils for making biodiesel. The rapeseed is a fourth break crop so their soilfertility is improving along with their financial viability.
Cox says while one property's production may not be enough for a commercial ethanol plant, if say10 orchardists got together, it would form the basis for contract production from someone willing toinstall it. The same feedstock could, dried and baled, be an alternative for coal in a boiler .
On more pastoral-type properties, pine trees are probably more suitable for land steeper than 15degrees, but other woody fibre short rotation crops can be considered on flatter land.
"On many farms you can have an opportunity for a mix and match in terms of production ofbioenergy feedstocks, the nature of the land, the market and timing," says Cox. "Farmers might bebetter off growing other species such as eucalyptus for example, which can have better value becauseof its other byproducts."
Cox says that as a nation we need to really start thinking about the potential for bioenergycrops as they can be a stimulus for the economic growth that the government is seeking.
His association has produced an 18 page document, '
The Ministry of Economic development Energy Outlook analysis supports the Association's (quiteconservative) numbers and assumptions and that the strategy supports a realistic scenario 10-15years out.
"We want to get the information out there, and gives the market view that this is what we thinkcould happen," Cox says.
"Entrepreneurs and land owners need to see that there are opportunities here."