The mainstream media is at last becoming aware of forestry as a sustainable energy resource, says Jim Childerstone of Jim's Forest Services. But it’s taken the likes of New Zealand's mega business, Fonterra, to make media headlines, he adds, with its most recent announcement in August being the establishment of an 11,000KW (11 megawatt) wood chip boiler for its Stirling cheese plant in South Otago.
A variety of biomass wood processing plant chippers, shredders and wood grinders, both mobile and stationary, are busily producing wood fuel for heat energy throughout New Zealand. They range from the massive Morbark and Doppstadt units munching up whole trees over a metre stem size, capable of producing up to 100 cubic meters of wood chips per hour, to the smaller mobile chippers capable of chipping skid site branch wood and rejected defect logs up to 450mm diameter, and stationary chippers mainly established in sawmills.
All this while recent media headlines stated that Huntly Power Station imported nearly 650,000 tonnes of coal last year to boost New Zealand's falling power supplies. The bulk of electric power is currently mostly sourced from renewable energy hydro schemes with a small percentage from wind, solar and other sources, including research into landfill energy recovery. Coal imports raise our greenhouse gas emissions by roughly 1.3 million tonnes per year (Scion research). Five industrial boilers running on wood biomass with a total output of 50 megawatts of energy saves 75,000 tonnes year (Polytechnik Biomass Energy). It’s going to take a lot of boiler installations and biomass just to mitigate what Huntly is using. Even every wood boiler in the country at present won't make it.
So what will? For more from Jim on the progress and challenges in this arena, get your copy of the November 2021 issue of NZ Logger magazine, on sale from November 1. Check the link on this page tosubscribe to either a printed or digital copy (or both).