Forestry Waste For Clean Power

Trees act as natural greenhouse gas sinks for carbon dioxide (CO2). But, when they're burned, landfilled or left to decay in the forest, CO2 is released back to the atmosphere, adding to the total greenhouse gas emissions.Ken Church of the CANMET Energy Technology Centre in Ottawa says that eventually the trees either decay or are burned, releasing greenhouse gases.The challenge is to capture and use the energy contained in trees or wood waste products.If wood waste is burned in a biomass electric generating plant, it can reduce demand for fossil fuelled power and reduce total emissions required to provide electrical energy to the economy, Church says.

Two Alberta projects are taking different routes to offsetting greenhouse gas emissions by burning biomass forestry waste.The Whitecourt Generating Station is using biomass to generate power that it sells to the Alberta grid, while the City of Grande Prairie is saving on electricity and heat costs by working with private sector partners to develop a power plant dedicated to local requirements.

This year, Grande Prairie, about 500 kilometres northwest of Edmonton, hopes to become the second community in Canada to become a home of a biomass power generation facility.Grande Prairie Alderman Carol-Lee Eckhardt sees enormous opportunities for her community to benefit from the power plant and the energy it will produce.

"In our case, it's a win for all project participants: the power company, the lumber company, and the Grande Prairie community and the environment," Eckhardt says."It saves tax dollars, creates local permanent jobs - about 20 of them - and prevents the waste of wood fibre and heat energy that previously went straight into the atmosphere from the waste burners.For the city, it also creates a direct cost savings of approximately $500,000 per year on the average cost of electricity."

When the plant goes into operation, it will consume all the wood waste from two Canfor sawmills in the area.Canfor's Chris Anderson says the sawmill operator has an agreement to supply all its wood waste to the power plant and steam heat.Electricity purchased at a low fixed rate will power the two sawmills and heat will be used in lumber drying kilns, eliminating burners to dispose of bark, shavings, sawdust and log ends.That will reduce fly ash particulates in the local airshed by more than 85 per cent.

"We'll receive a stable power price, an advantageous heat cost and we'll eliminate two waste burners," Anderson says."There are economic benefits and there are certainly environmental benefits."

Matt McCulloch of the Pembina Institute for Appropriate Development says biomass power plants using forestry wastes as fuel produce some particulates and nitrogen oxides but have far fewer emissions than beehive burners.And greenhouse gas emissions are negligible compared with landfilling forestry wastes, which produce methane.

Furthermore, McCulloch says, biomass power reduces the need to generate electricity from fossil fuels.

According to Pembina's Green Power Marketing Report, one megawatt hour (MWh) of biomass power produces 38 kilograms of greenhouse gases (GHGs), compared with an Alberta average 950 kilograms of GHGs per MWh of power generated by all sources.

In its latest Energy Supply/Demand Report, the National Energy Board says biomass provides an annual 66 petajoules of primary energy across Canada, mostly generated by the forestry industry and consumed by them for heat and power. This is about 1.9 per cent of Canada's total 3,398 petajoules of primary energy supply.

Eckhardt is optimistic about the potential of distributed power generation.She says small, local power plants based on biomass waste are quicker to build when needed, less capital intensive than much larger coal-fired plants, and eliminate the waste of resources.

"This is brand new to Alberta and North America but it's old hat to Europe. It's been going on there for 50 years. Our luxury of space and resources is almost to our detriment at the moment.It's almost as if we, in Canada, were at a disadvantage because we have it all."
Although a bright future is painted for this technology, its capital costs are higher than any conventional (fossil fuel fired) power generation technologies.

"This technology isn't free," says Peter Keskinen, a vice president with Probyn and Company that designed the Whitecourt Generating Station, about 150 kilometres northwest of Edmonton."The capital cost is way higher than for coal- or gas-fired plants," says Keskinen.At the Whitecourt station, it costs about $2,000 per kilowatt hour, consistent with the average biomass plant worldwide but far higher than the $1,500 for coal-fired plants and $1,000 for gas-fired facilities. "But the fuel is essentially free," he adds.

Although an initial high capital cost is required, the power prices offered by the plant are competitive with others on the Alberta grid.

The Alberta Small Power Research and Development Act sets rules for independent power producers to sell power to the Alberta grid at fixed rates, geared to inflation, under long-term contracts that make financing available.Larger plants on the other hand sell power as required by users, based on a hierarchy in which low-cost plants operate continuously and higher-cost plants are called on as demand rises.

"The station is guaranteed a fixed rate of $63 per MWh of power, which compares with a range of generating costs on the Alberta grid between $35 and more than $200 per hour," Keskinen says.

Due to improved operations, the company has boosted the plant production from original design capacity of 20.7 MW, which is sold under the fixed-rate contract to the Alberta grid, to 24.7 MW.Those additional four MW are sold onto the grid at market rates, enabling the plant to earn higher returns during hours of peak demand.

Of the total 200 MWh of annual power output, Edmonton-based EPCOR buys 67 MWh that it markets to homeowners through its Green Power program.It's a fraction of total plant output, but EPCOR's Tannis Tupper says that's not the measure of the power company's interest in biomass. She says EPCOR will exercise its option to buy more biomass power when the demand from the consumers increases.

Tupper thinks that the reasons for consumer apathy are complex, one of them being the esthetics.

"With biomass, they're still looking at a stack that releases an emission," she says. The idea that wood waste produces emissions -no matter what - and that biomass power reduces the need for new coal-fired capacity is just too complex for the public to embrace.At the residential level, it's not their favorite choice," she states.

Pembina's Andrew Pape-Salmon says a legally binding target for increased renewable energy development is needed from the Alberta government to help compensate for the lack of financial valuation of environmental costs in the marketplace. This will help boost producers' interest in developing those forms of energy.