Online calculators help sawmillers utilise wood-waste for energy

7 February 2007

New Zealand sawmillers are being encouraged to find economic value in wood waste, with the help of a range of online bioenergy calculators.

The calculators, developed by bioenergy specialists at Crown Research Institute Scion in Rotorua, have been created to help the 300 odd sawmilling companies in New Zealand find ways to reduce costs by using wood waste for energy.

In sawmilling about 50 percent of wood ends up as a waste product. But that ‘waste’ does have different uses – for example bark can be sold to garden centres, or the wood can be used as a fuel to replace fossil fuels such as coal.

Michael Jack, a senior scientist in Scion’s bioenergy group, says wood waste is often viewed by sawmillers as having no value, so the calculators are aimed at helping them asses the economic value of the waste wood as a fuel and determine the most beneficial technology for extracting that value.

“Often sawmillers will come up with some good ideas for how to use the wood waste they create, but to test out their theory can be expensive. By using the tools we’ve created, they can get an estimate of the economic return and value – before getting consultants involved in feasibility studies,” he says.

The tools that are available include estimating the economic value of wood waste, assessing the economic return from replacing fossil fuel burners with wood waste alternatives for heat and power generation, and calculating the energy content of wood waste.

“There’s a lot of science behind the calculators and they are based on the knowledge Scion has gained over many years. But we are presenting that science in economic terms that has meaning and real application for sawmillers,” Dr Jack says.

The calculators are aimed at small and medium sized companies as pre-feasibility decision-making tools. Dr Jack says the calculators are unique because they are specificly designed for sawmillers.

“There is a lot of general information about bioenergy  out there but it is often very technical. It is difficult for any industry to get specific quality information that they can actually use to make a difference to the way they do business. That was our challenge,” he says.

The bioenergy team is planning to expand the calculators to include tools for forest growers to look at the value that can be gained from using wood waste produced during harvesting for bioenergy.

The calculators are part of a new Bioenergy Knowledge Centre, an initiative funded by the Forest Industry Development Agenda Bioenergy Programme.

Sawmillers can access the calculator at or can get more information at 0800 BIOENERGY.