Wood fired steam powering wilding conifer business

3 October 2023

Developing commercially successful projects from environmental challenges is bread and butter for the Central Otago social enterprise Wilding & Co. By extracting high value essential oils from invasive Douglas fir, the Queenstown business has removed thousands of the unwanted conifers from local high-country farmland. Constantly seeking to improve the environmental and economic performance of their business, Wilding & Co. have set an ambitious new goal of cutting out diesel fuel.

In order to decarbonise their operation, Wilding & Co. is working with Canterbury based start-up Mackwell & Co. to develop a 35hp Steam tractor that meets all of their energy needs. Capable of generating clean energy from abundant forest available fuels, including green wood-chip, hogged forestry slash and dry firewood, the Mackwell A35 is a modern steam engine unlike any other. For Wilding & Co., the Mackwell A35 will generate all of the steam power they need for distillation, hauling feedstocks and running PTO powered chippers and generators.

Wilding & Co. founder Michael Sly recently travelled to Mackwell’s Christchurch workshop to test his distillation unit with their 400hp (2MW thermal) prototype boiler. Michael was impressed with the Mackwell boiler’s speed to reach full pressure, ability to use a high moisture content fuels and the clean and safe, low volume – high temperature combustion system.

Predicted to come to full pressure in just 10 minutes, Michael considers the A35 Engine to be a “game changer” for small to medium scale operators, who generally find biomass boilers unviable due to safety concerns and the length of time they take to reach full pressure.

In recent years, diesel has become one of Wilding & Co.’s major operational expenses so the adoption of Mackwell’s advanced-steam technology promises to significantly improve the enterprise’s bottom line. Having crunched the numbers himself, Michael says the ability to use waste biomass steams to displace their most expensive input is a “no brainer”.

Further, the A35 promises to slash Wilding & Co.’s operational carbon emissions by over 96%. Wilding & Co. already leverages ecological benefits of removing wilding pines to market his premium oil product and sees an opportunity to further enhance their band position through decarbonisation.

Source: Mackwell & Co