By Gavin Evans
Nov. 21 (BusinessDesk) - Wood fuel could dramatically reduce New Zealand’s industrial emissions within five years, but
not without a policy framework that actively encourages it, Azwood Energy general manager Brook Brewerton says.
The country has abundant wood residues sitting in its hills which can be transformed into energy, he says. Some firms
are starting to look at it as an alternative to coal, but many lack the capital to make the change.
Without that demand that fuel will remain in the hills, he said. The quickest way to drive that would be for the
government to provide accelerated depreciation on renewable heat plant, or low-interest Crown loans for them.
“It’s just waste and we can use it but we need to create the demand,” he told BusinessDesk.
“Biomass is a proven technology and with a long-term, secure, mapped supply strategy it could dramatically cut our
emissions over the next five years.”
Heavy industry accounts for about 15 percent of the country’s emissions. Food processing, heavily reliant on hot water
and steam, accounted for about a third of the almost 9 percent that came from manufacturing in 2016, according to
government data.
While the scope to reduce emissions from some high-temperature processes like steel and cement making is considered
limited, the Productivity Commission earlier this year recommended that the Ministry of Business, Innovation and
Employment and the Energy Efficiency and Conservation Authority take a more active role developing policy to reduce coal
use in process heat, including greater promotion of biomass supply and use.
Crown forestry research institute Scion estimated New Zealand produced about 5.5 million tonnes of wood residues last
year, of which just over 3 million tonnes – or 22 million gigajoules of energy – could be recovered. It expects those
recoverable volumes to peak at 4 million tonnes and 27 million GJ in 2022, and trough around 2037.
Azwood has been recovering forestry waste around Nelson for 40 years and considers the Scion estimates conservative.
While the national residue volume is dominated by the Bay of Plenty, Brewerton notes that all regions have some wood and
current demand is low. If demand did take off a lot could be done to use empty trucks and rail wagons on return trips to
shift wood waste around the country.
Brewerton said a real barrier to current uptake is the poor advice some firms get on boiler design and fuel
specification. Many consultants are not really across the technology and some are still designing projects with a
“fossil fuel” mindset and little understanding of the properties of wood and how to burn it properly.
Azwood executives have previously complained that some projects are being designed for wood chip boilers when
lower-cost, larger grade ‘hog’ would be a more economic wood fuel for larger-scale users.
Azwood is supplying Fonterra a blend of wood chip and hog which the company is blending with coal to reduce emissions
from its Brightwater milk powder plant. It will use about 2,000 tonnes of wood a year.
The company also plans to convert its cheese plant at Stirling, near Balclutha, using industrial scale heat pump
technology to run on electricity. That will reduce coal use there by about 9,700 tonnes annually.
Chris Win, Fonterra’s operations manager for the upper South Island, said sites looking at alternative fuels have to
look carefully at their overall energy needs.
Energy efficiency remains a major driver, but firms also have to look through their lower heat processes to see what can
be provided with electricity, what still requires thermal and what lower-emission options they have for that, he said.
Developing a plan, without closing out options to use technologies that are still evolving or not yet economic, is also
key.
“We need to get going on this as a country and as a company,” he said.
(BusinessDesk)
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