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Wood
The Yukon Government is committed to encouraging the development of local energy resources, as a way to:
Wood has been an important fuel throughout the Yukon's past, and shows promise as a means of continuing to keep Yukoners warm. In some cases, wood fuel may also have limited potential for export, and as a means of producing electricity. The forests are currently a source of commercial and residential heating fuel, and support existing small industries in sawmilling and firewood cutting. Fuelwood supplies approximately 25% of the space heating requirements of the residential sector, and its use represents approximately $4 to 5 million annually in direct employment and import substitution. As the timber harvest increases, so does the potential for generating power from wood waste, and for producing wood fuel pellets. A critical factor in these ventures is the long-term timber supply. A sustainable forest management policy is currently under development, led by the Yukon Forest Commission. Its goal is to provide stable and sustainable development of the Yukon's forest resources to support economic growth, while maintaining wilderness values and ecosystems. Accurate information is required for decision-making, with public, community and First Nation involvement in all management decisions, employing a cautious approach where the risks are unknown. Capital intensive forest products industries need high volumes, and high volume production may not suit Yukon conditions. However, wood in Yukon forests has certain advantages over that of other areas where conditions might seem, at first glance, more favourable. Due to the shorter growing season, Yukon wood has a higher density, which gives it greater strength and durability. Recently the seeds of Yukon lodge pole pines were in demand in Scandinavia: during the ice ages significant portions of the Yukon were not glaciated, so Yukon trees were regenerated from stock that had adapted to the long summer days; the forests of northern Europe had not been protected from glaciation by high coastal mountains, and after the ice ages had passed, were regenerated by trees from the south, less capable of coping with northern growing seasons. There is a need for long-term tenure when using wood wastes to generate electricity, since such systems are capital intensive and require long-term security of supply in order to obtain financing. The stable and sustainable harvest of the Yukon's timber resources will encourage capital intensive industries producing a variety of wood products. The waste material from these operations can be used to provide useful energy products, including processed wood fuel pellets and electricity. Historical Use Wood has been used by the first people in the Yukon for thousands of years for warmth and cooking, and today represents an important source of home heating for many families and some small businesses. During the gold rush, riverboats were used to transport freight and passengers. From the mid thirties to the mid fifties there were five boats operating on the Yukon and Stewart Rivers, and on Bennett Lake. The boats required four cords per hour, more or less continuously from June through mid-October. Wood camps were located all along the routes, and may have produced as much as 80,000 cords per year. There were even more boats operating during the earlier part of the century. During the building of the Alaska Highway, a district heating system operated in Whitehorse, supplying steam to heat numerous buildings in downtown Whitehorse. Rising energy prices in the 1980s made wood heating very popular, and with the upsurge in woodstove installations came local woodsmoke pollution. The City of Whitehorse established an education program to teach residents to burn wood with a minimum of smoke, coupled with a bylaw to prohibit wood burning when pollution levels are forecast to rise beyond acceptable limits. In recent years a number of wood chip fired boilers have been installed by the Yukon Government and some First Nations to heat larger buildings, and groups of buildings. Wood chips have been successfully used as an alternative to fossil fuels at the Eliza Van Bibber School in Pelly Crossing since 1983. Since the installation of that boiler system, several more have been installed in the Yukon: at the Elijah Smith School in Whitehorse, Insert photo of boiler room at Elijah Smith School a wood-chip fired district heating system to service several buildings owned by the Champagne & Aishihik First Nations in Haines Junction, and at the Administration Building of the Little Salmon Carmacks First Nation. Others at Burwash Landing and Teslin are under construction or under consideration. Similar systems are in use in wood products manufacturing plants in Alberta, Winnipeg and Montréal. Small automatically feeding wood pellet heaters are becoming increasingly popular for homes and small businesses. A pellet-burning appliance may be operated in the Whitehorse woodsmoke control zone during no-burn periods, because they emit relatively little smoke compared to most woodstoves. Heating with wood pellets currently does not offer cost savings over the use of oil; however, that situation is expected to change in the near future when wood pellets are manufactured in the Yukon. At the time of writing, a wood fuel pellet plant is being set up in Teslin. The owners expect to be producing pellets by early fall, and marketing them in the Yukon at a price considerably less than for imported pellets. Critical Factors affecting the Use of Wood Chips in Public Facilities Infrastructure factors
Technical and economic factors
Institutional factors
Traditional methods of producing heat from wood are well understood, as are their drawbacks: local woodsmoke pollution, potential fire hazards, effort required, and expense. However, changes in technologies available for burning wood now make it a practical option to supply much of the Yukon's space heating requirements. Large wood chip burning boilers have been installed in a number of Yukon schools and buildings owned by First Nations. The Champagne & Aishihik First Nations operate a wood chip fired district energy system, to heat their elders' complex, youth centre, laundry, administration building and workshop. The Little Salmon Carmacks First Nation has a wood chip boiler for their Administration Building, and the Kluane First Nation has ordered another for theirs. Wood chips are also being considered as a heating source for municipal buildings in Haines Junction and Teslin. Problems with the wood system are normally limited to the feed system. They can also be hand-fired, which ensures a reliable heating system for the building. Boilers can operate with wood of varying moisture content: testing conducted on the boiler at the Eliza Van Bibber School in Pelly Crossing showed only a slight decrease in efficiency when green cordwood and chips (30% moisture content) were burned, compared with firekilled chips (moisture content 10%). However, in fuel purchase contracts it is important to adjust the price of the fuel according to the moisture content (up to a specified maximum). Although these units operate with few problems, they have yet to deliver on expected savings. The reasons are a lack of efficiency in fuel harvesting and fuel handling at the sites, which have elevated the cost of producing heat beyond that of using the more conventional and convenient fuels: oil and propane. A greater degree of mechanization and more competition in the sector will improve the economics. A competent enthusiastic operator can fix problems as and before they occur. Chippers require routine maintenance and regular sharpening of knives to avoid large chips which can cause bridging and jamming of a boiler's feed system.
Local Markets The forests are currently a source of residential heating fuel, and support existing small industries in sawmilling and firewood cutting. Fuelwood use represents approximately $4 to $5 million annually in direct employment and petroleum import substitution. As the timber harvest increases, so does the potential for generating power from wood waste, and for producing wood fuel pellets. A critical factor in these ventures is the long-term timber supply. Fuelwood consumption During the period 1970 through 1993, the permits to harvest fuelwood averaged 52,000 cubic metres per annum, the heat energy equivalent of approximately 11 million litres of fuel oil. This represents approximately 25% of the space heating energy used by the residential sector. For every cubic metre of firewood burned, 220 litres of fuel oil are displaced, or at a wholesale price of $0.27 per litre this represents $60 in import substitution. At a volume of 50,000 cubic metres per annum, the average annual fuelwood harvest over the past 25 years, wood fuel represents a contribution of some $4 to $5 million to the Yukon economy, and a significant personal saving to individual consumers. The Yukon's total annual space heating requirement of 2,635 terajoules (TJ) could be supplied by the forest residues of 340 thousand cubic metres of logging, or through the harvesting of 37 square kilometres of typical firekill. This represents approximately 3% of the total destroyed each year by fire, on average. Between 1979 and 1996, the City of Whitehorse issued 3,406 woodstove installation permits. Approximately 20 to 25 thousand cubic metres of fuelwood are consumed each winter in Whitehorse. Wood could be used as an energy source in a thermal electric plant to produce electricity, although it suffers from most of the disadvantages of coal-fired power plants in the Yukon: high capital costs, the risk of stranded investment when power requirements are reduced, the need for highly skilled full time plant maintenance staff and operators, and the relatively high capital costs due to the small scale of plant required. Making Electricity from Wood Wastes It has been estimated that the wastes from 70,000 cubic metres of saw logs could produce a steady 2 MW of electricity, or 16.8 GWh per annum. This is about 30% more electricity than is used by the community of Watson Lake. One tonne of wood contains about 5,000 kWh. Unfortunately, it is difficult, on a small scale, to convert heat into electricity. Studies done for the Yukon Government by H. A. Simons Consulting on using coal to operate a 20 MW power plant (see Coal Resources paper) indicated that 20 MW is small by comparison with most thermal power plants, and smaller plants tend to produce expensive electricity due to the relatively high capital costs and the need for a highly skilled, full-time staff to tend the equipment. Electricity from a plant of that size would be competitive with diesel only if the plant could be operated year-round on low cost wood waste. At this time there is neither the wood waste nor the electrical load. Smaller plants have been studied for specific applications. The sawmill in Watson Lake, operated by Cattermole Timber until the early 1980s, made use of a steam-fired turbine to produce approximately 1 MW of electricity, when the equipment was functioning, for use by the sawmill. The sawmill was burning the waste material anyway to dispose of it, and some steam was needed to heat the plant. Cattermole ceased operation in the early 1980s. When the sawmill was refurbished, the new owners examined the potential for bringing the power equipment up to standard, but concluded that it would be too costly. They also examined the potential for generating 6 MW to supply virtually all of the electricity needed for the mill and the community, but again concluded that the pay-back period was too long. A critical factor in generating wood-fired electricity is the long-term supply of fuel at a very low cost. Only if the sawmill were operating would there be low cost wood waste. A study was done for the community of Pelly Crossing in the early 1990s. Although the use of wood fuel to generate electricity has the potential to create long-term jobs in fuelwood harvesting, the cost of producing electricity in this manner is several times that of using diesel generators, due to the high capital costs, the cost of harvesting wood fuel, the inefficiency of conversion of the energy in wood to electricity, the need for round-the-clock, highly skilled plant operators, and the limited demand for electricity in the community. Thermal power plants that convert steam to electricity require high temperature high pressure steam in order to obtain reasonable efficiencies. Typically the very best thermal power plants convert fuel to electricity at an efficiency of about 40%, roughly the same efficiency as a well maintained base load diesel engine. The 30 MW coal-fired fluidized bed power plant at Piney Creek, Pennsylvania, operated by Tampella Power (see Coal Resource paper) operates at an efficiency of about 30%. By comparison, reciprocating steam engines can have efficiencies less than 10%, due to the use of lower temperature steam and the difficulty of transferring heat from the cylinders. During the time of their active service, the riverboats typically used steam at close to atmospheric pressure and then condensed it in the cylinder, pulling the piston in with the vacuum. The riverboats used a lot of wood, typically 4 cords per hour; in other words each boat consumed energy faster than all of the diesel power plants in the Yukon's off-grid communities. There may soon be a better way to produce electricity from wood fuel, however. Research is being conducted on a power plant that uses hot gas in a turbine to produce electricity. While it is still in the early development stage, this method of turning the thermal energy in wood to electricity has the potential to produce electricity at efficiencies of about 25%, with another 50% of the wood energy available for heating buildings. Because no high pressures are involved, the plants can be designed to operate unattended. Comparison of Electricity Generation Options
Export Markets At best a tonne of wood displaces about $150 worth of oil in a residential market. Normally, because of its bulk, wood fuel normally cannot be economically transported for more than a few hundred kilometres. Compared to cordwood or raw wood wastes, processed wood fuels are less sensitive to transportation costs. A tonne of pellets occupies only about one quarter the space, and can sell for half again as much, as cordwood. Yukon logs have been exported in recent years, to a greater and lesser extent, depending on market fluctuations. Policies to determine the extent of the allowable cut and products to be exported are being developed in consultation with stakeholders. Wood wastes from logging and milling operations, available for energy, will vary depending on the export product.
Employment Firewood sells for between $100 and $200 per cord in the Yukon, depending on location. The bulk of the money spent on firewood goes to wages, and is spent within the community. Wages account for approximately half of the cost of producing wood pellet fuel. The production of 1,000 tonnes of wood pellet fuel creates 2 to 3 person years of direct employment. Employment is created at every step of the process, from the harvesting of wood wastes at logging sites, to transport of wastes, pellet manufacturing, sales, and delivery. Other Benefits The harvest of fuelwood is an important family tradition for many Yukoners, and provides not only a source of warmth but a sense of accomplishment and shared activity. Safety Proper installation of wood combustion appliances is specified by the National Building Code of Canada, which is enforced by the public safety departments of the territorial or municipal governments. Clearances from combustibles must be observed at all times. Routine inspection and cleaning of the chimney should be conducted to ensure that the buildup of creosote does not exceed 5 to 10 mm. Industrial boilers larger than 2 MW require an operator. Electricity generation normally involves pressures and temperatures that necessitate a First Class steam engineer. The use of large boilers is regulated under the Yukon Pressure Vessels Act. Competing Resources Each of the fuels has its advantages and drawbacks. The need for backup should be considered with any heating source, since each, with the exception of cordwood, depends on electricity to work.
Why install a pellet-burning stove?
Other considerations: An oil-fired space heater is smaller, slightly cheaper to install, at the time of writing costs less to operate (although with pellets manufactured in the Yukon that situation is expected to change), is quieter, more convenient, and will not cause an increase in fire insurance premiums. Since 1993 there have been approximately 150 wood pellet stoves installed in Whitehorse and over 300 conventional woodstoves. Pellet-burning appliances represent about 30% of new installations. Processed wood pellets can be conveniently loaded into a van with a forklift, and backhauled to points south. Markets outside may provide local pellet manufacturers with an important outlet for their product while sales build in the Yukon to levels that can sustain a manufacturing plant. To be sure that a pellet stove is both clean-burning and efficient, check to see that it has been tested and met EPA Phase II or CSA B415 standards. Pulp quality chips (bark-free, rot-free, species sorted, uniformly-sized) are sold to pulp mills in bone dry units (BDU). A BDU is 2,400 pounds. It takes approximately 3 cubic metres of log to produce one BDU of chips. In producing one BDU of chips, there is approximately one third of a cubic metre of bark available to be used as fuel, which has the energy equivalent of 65 litres of oil. While many forest industry products are energy intensive, their production creates an opportunity to use wood wastes to produce much, if not all, of the power required in their operation. A report on Forest Industry Development Options, prepared for the Department of Economic Development, estimated the power requirements of a plant producing 150,000 cubic metres of MDF (medium density fibreboard) at 68 GWh of electricity per annum, or about 10 MW. The bark alone from the 400,000 cubic metres of wood required could produce over one quarter of that power. Given an opportunity to harvest other waste wood in the logging and milling operation, it is likely that such a plant could produce all of its energy from wood wastes and have surplus power for sale to other customers. Forest Policy Administrative Control of Yukon Forests The Federal and Yukon Governments, in conjunction with Yukon First Nations, are developing a Yukon Forest Strategy which will help guide the development of a Yukon Forest Act. The administrative control of the forest resources will pass at that time from the Federal to the Yukon Government. The transfer is currently due to take place October 1, 1998. For further information on the Yukon Forest Strategy and related forest management publications contact the Yukon Forest Commission at 393-6424, or visit the web site at: www.yukonweb.com/government/forest/ Permiting Process Timber harvesting requires either a timber permit or a timber harvesting agreement, either of which is currently issued by the Department of Indian Affairs and Northern Development (DIAND). All forest harvesting activity must comply with regulations governing land use, protection of historic sites, workers' compensation, health and safety, water use, waste disposal, and fuel storage, among others Development Assessment Process (DAP) The Environment Assessment and Review Process (EARP) was replaced in January 1995 by the Canadian Environmental Assessment Act (CEAA). The Development Assessment Process (DAP) will be the Yukon's new assessment process once legislation is in place, and will cover the same types of projects now addressed under CEAA, including land use, water, socio-economic, and environmental impacts of development projects, such as road upgrading and power line construction. DAP is specified by the Umbrella Final Agreement on Yukon First Nations' Land Claims. Small-scale harvesting will be assessed by the designated offices in the communities. Larger projects will be assessed by the Yukon Development Assessment Board in Whitehorse. Environmental Impacts of Harvesting Fuelwood Environmental impacts of course vary considerably depending on the forest type, the terrain, the climate, and the state of the forest. Salvaging insect-damaged or firekilled timber has a distinctly different impact when compared with logging green timber stands. Many of the impacts listed below can be mitigated through silviculture and good forest management practice. Visual impacts Soil Erosion Changes to water retention Loss of habitat Changes to soil fertility Changes to climate Environmental Impacts of Burning Wood Local Woodsmoke Pollution Residential woodstoves can produce high levels of respirable particulate matter. In densely populated areas, woodsmoke tends to accumulate during certain weather conditions, notably temperature inversions with little wind and at a temperature of about -10° to -30°C. Woodsmoke has been identified as a health threat by organizations such as the Yukon Medical Association and the US Environmental Protection Agency (EPA). High levels of woodsmoke can lead to acute health problems, especially in children and the elderly, resulting in increased school absenteeism, hospitalization, and risk of death from respiratory causes. Woodsmoke is composed of fine particles, many of which are small enough to be deposited in the lungs, where, over time, they can set up an inflammatory condition leading to cough, asthma and shortness of breath that in turn can lead to chronic bronchitis, emphysema and possibly cancer. The Yukon Medical Association advises that health effects increase with woodsmoke levels, and that people experiencing worse than normal symptoms should consult their physician. The City of Whitehorse has responded to the problem of woodsmoke pollution with a program of education on how to operate a woodstove with a minimum of smoke. The City has also passed bylaws which specify maximum opacity, and when necessary, prohibit burning, to keep pollution at acceptable levels. Since April 1997 all new woodstove installations in Whitehorse must meet CSA (Canadian Standards Association) and US Environmental Protection Agency (EPA) emission standards.
Greenhouse Gases The issue of climate change was addressed by a Convention and Declaration at Rio de Janeiro in 1992. Canada has established a Voluntary Climate Change Action Plan and Registry Program. Both the Canadian Electricity Association and the Coal Association of Canada have signed a Memorandum of Understanding with Natural Resources Canada. Greenhouse gases are emitted when any fossil fuel is burned. They are also emitted during the stages of exploration, extraction, transport, refining and distribution. When wood fuel is burned there is no net increase in greenhouse gas emissions, provided that a tree grows in place of the one that was cut down. In the case of firekilled wood, the same carbon dioxide is released regardless, whether immediately when the wood is burned in a stove, or over a period of years when the wood decomposes and returns to the soil. Wood Ash Wood ashes in too great a concentration represent an environmental hazard, but spread evenly on the soil can be a valuable fertilizer. In New Hampshire wood ash is used as an environmentally sound fertilizer. Farmers in that state save approximately one half million dollars per year in fertilizer costs through the use of wood ashes.
A cord of firekilled (or other well seasoned) spruce or pine weighs about one tonne and contains about 18 GJ (gigajoules) of energy, or 5,000 kWh. Well seasoned air dried wood contains about 10 to 12% moisture by weight. Hardwoods (deciduous trees) contain more energy per cord or per cubic metre than softwoods, because they are denser (poplar being an exception). Softwoods contain slightly more energy per kilogram because they have a higher hydrocarbon content (pitch). Moisture in wood is reported either on a wet or dry basis. Wet basis refers to the percentage of the total weight that is water; thus it cannot exceed 100%. On a dry basis water is reported as a percent of the weight of the dry wood fibre, in which case it could exceed 100%. Fifty percent moisture wet basis would equal 100% moisture dry basis. A bone dry unit (BDU) of pulp chips weighs 2,400 pounds, and normally takes approximately 3 cubic metres of log to produce. Bark contains approximately the same energy content per kilogram as does wood. However, bark contains considerably more ash. In manufacturing fuel pellets, care must be taken to keep most bark out of the feedstock, to stop the ash from fusing in the pellet stove's normally small combustion chamber. A cubic metre of green wood at 50% moisture content (wet basis) weighs approximately 760 kg. In other words, it has a specific gravity of 0.76. In 1992, eight wood-fired power plants generated 10 percent of the electricity in the state of New Hampshire, while displacing 68 million barrels of oil, creating 800 jobs, and providing an economic benefit of $282 million statewide. One kilotonne of wood with a moisture content of 30% (wet basis), producing electricity at an efficiency of 25%, can make one GWh of electricity. A wood pellet plant producing 3 tons per hour, operating for one shift per day would produce approximately 6,000 tons of wood fuel pellets in a year. Since each stove burns about 6 tons per annum, one small plant could supply nearly 1,000 pellet stoves. Glossary of Energy Terms
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Overview
Last Updated 12-10-2005