FIRST THING Toso Bozic says type and availability of wood waste is the first consideration, and technology second, when considering biomass heating or power generation
A key source of energy in Alberta is going up in smoke — but Toso Bozic is trying to change that.
“Every small, rural county in Alberta right now probably burns on average 1,000 tonnes of wood a year, and it costs them money to do it. Larger counties burn much more than this,” says Bozic, bioenergy specialist and agroforester with Alberta Agriculture.
His job is to help rural communities and businesses design heat- and power-generation systems using biomass, which includes producing pre-feasibility studies to answer many of the questions related to wood fibre costs and availability.
Using wood fibre as fuel to generate heat and/or power takes careful planning to answer important questions related to wood quality, cost, availability, processing, transportation, and storage to design a dependable and economical system, he says.
Bozic says the first question potential woody biomass suppliers and bioenergy producers need to ask is who controls the wood source? The second question is how available is it? Potential wood sources include private woodlots, forestry companies that typically burn ‘slash’ (such as branches and treetops), or wood waste accumulating at a sawmill, pallet manufacturer, construction company or municipal landfill.
“But I’d like to dispel a myth, which is that there is no such thing as ‘free wood,’” Bozic says.
There are always costs associated with negotiating supply contracts, harvesting, gathering, pre-processing and transporting the wood, he says. The closest example of ‘free wood’ is wood waste that businesses pay to dispose of. Wood waste sent to landfills is another potentially low-cost source of biomass. But the type and quality of wood fuel needs to be matched to an appropriate bioenergy system.
“You should look at fuel sources first, and then at the technology,” says Bozic. “You look at a system that addresses your fuel characteristics, such as size of wood chips, moisture content, and contamination.”
It’s also important to have more than one supplier if the material is being supplied on a contract basis to ensure there is a dependable and consistent fuel supply, he says.
The logistics of transportation and storage are also important considerations, including whether some processing of what is often bulky, lightweight material should be done prior to transportation. The storage system should be designed to hold sufficient reserves and for easy material handling. It’s not particularly challenging to convert an existing boiler system from using fossil fuels like natural gas to woody biomass, although having a dual-energy system allows temporary use of natural gas should biomass supplies run short, says Bozic.