Thursday 25 July 2013


What are the problems?

The timber industry believes it has had a big win with the NSW Government proposing to change the Protection of the Environment Operations Regulation, so that “waste from land rehabilitation activities involving the removal of invasive native scrub and logging debris from approved forestry operations on State forest or private land may be burnt to generate electricity”.

Some timber mills have long been using waste material from the milling process, to kiln dry timber and generate electricity. Sugar mills have also operated co-generation plants, burning a mixture of cane trash, mill waste, and noxious trees like Camphor Laurel.

However, building power stations specifically to burn logging residues is fraught with financial danger, because tree crowns and stumps, what most people see as forest waste, cannot be economically field chipped and transported large distances to power stations. Wood-fired power stations cannot compete with coal-fired generators, built adjacent to a mine where coal is fed straight from the pit into the furnaces by conveyor belt.

Environmentalists fear that, in the same way the wood-chip industry gained a foot-hold, claiming it would only use logging waste, biomass proponents will end up burning enormous quantities of logs from native forests when they find that 'waste' simply isn't an option.

Other than the fact that there are no convenient mountains of logging waste available, burning wood, as with coal, emits greenhouse gasses and toxins, with some 90 different compounds released during the burning process. A 2008 Canadian Government report identified 45 that are seriously detrimental to human health, including formaldehyde, hydrogen sulphide, cadmium, hexavalent chromium, cobalt, lead arsenate, phosphorus, mercury, hydrochloric and sulphuric acids, and sulphur dioxide.

The crunch is that while it's possible to filter out those compounds, it's prohibitively expensive. Even an adequate filtration system, one that reduces emissions to acceptable levels, costs about the same to run as the generation plant itself. Therefore, in order to make a wood-fired power station economically viable, we need solid logs sourced nearby, and a filtration system that filters out enough of these toxins to comply with whatever some bureaucrat proclaims to be “safe levels”.

- J Edwards