Vegetation is called biomass in the energy world and the use of biomass to produce energy is referred to as bioenergy.
The sun's energy is the basis of biological life on Earth. Some of the sun's energy heats the ground and atmosphere and is stored by vegetation. The vegetation grows using solar energy, nutrients and minerals from the soil, and carbon dioxide from the atmosphere. The oxygen the vegetation produces as a by-product of photosynthesis supports other forms of life on the planet.
Bioenergy is considered a neutral fuel in the global warming debate. Living trees and other vegetation lock up carbon dioxide, a greenhouse gas, and store it until they die and decay, or are harvested and burned. Although burning wood and other biomass produces carbon dioxide, no more is produced through burning than was consumed by the tree during its growth. Therefore, as long as new trees are allowed to grow in place of those harvested a carbon balance is maintained. For this reason bioenergy is not considered a net contributor to greenhouse gases.
When a tree is burned, energy stored as carbon combines with oxygen from the atmosphere in a chemical reaction called combustion. Heat and light is produced and carbon dioxide is released as a by-product. The combustion process also releases other minerals and nutrients absorbed by the tree when it was growing, reversing in minutes the long process that led to its growth.
Today, close to 25% of Yukoners (compared to about 5.4% of the population nationwide) rely on wood for home heating. Many more Yukoners use wood heat as a back up or supplementary source of heat. This translates into an annual fuel wood consumption of up to 55,000 cubic metres or 22,000 cords. While this sounds like a lot of wood, it is actually less than 5% of the average annual firekill from forest fires. Over 90% of Yukon fuel wood is harvested from fire killed trees.
Many homeowners cut their own wood, but there is also a healthy commercial fuel wood market in Yukon. The supply of fuel wood has been valued at approximately $4 million a year in economic benefits and import substitution. Cordwood, delivered in 2.5 metre (eight-foot) lengths or cut to stove length, serves most of the market. Entrepreneurs have also made efforts to sell wood-chip, wood-briquette and wood-pellet fuels. Since wood is a high volume fuel, transportation is a significant factor in its cost, and firewood supplies are not always close to markets. Before installing a wood stove, homeowners should consider the likelihood of increased home insurance costs. When heating with wood, use dry wood, and burn cleanly to maintain local air quality. Remember, within the City of Whitehorse, only EPA-certified woodstoves may be installed.
Over the last decade, much has been learned about the science of wood burning. Wood can be a safe and economical fuel. Careful attention paid to stove selection, installation (for example, chimney size, location and height), wood quality and burning practices will minimize effects on air quality and health, and reduce the risk of fire. A fast-burning fire in a high efficiency woodstove uses less wood and consumes most of the harmful smoke particles and chemicals found in unburned woodsmoke. If you follow the wood-burning advice offered here, carbon dioxide and water vapour will be the main ingredients in your chimney gases.
Biomass can be converted directly into liquid biofuels for use in our vehicles. The two most common types of biofuels are ethanol and biodiesel.
Ethanol is a renewable fuel distilled primarily from corn. It is blended with gasoline to reduce carbon monoxide pollution and the exhaust pollutants that contribute to smog. Each gallon of corn ethanol used in a 10% blend with gasoline cuts greenhouse gas emissions 12 to19%. The ethanol content in gasoline can be as high as 10% without needing to modify standard engines. Many automobile manufacturers make “flex-fuel” versions of their standard gasoline-powered vehicles that can use even high blends of ethanol. In the future, ethanol will be produced from cellulose feedstocks such as wood waste and agricultural residues.
Biodiesel is a renewable fuel produced from oilseed crops or used cooking oils and unwanted animal fats. Biodiesel has significantly lower tailpipe emissions and addresses the urgent need to reduce emissions of carcinogenic diesel particulates. In addition, biodiesel’s lifecycle emissions of heat-trapping carbon dioxide are 78% lower than that of petroleum diesel. Biodiesel can be blended at any level with petroleum diesel, but is most commonly found mixed at a ratio of 20% biodiesel to 80% petroleum diesel (B20). At very low blends of 1 to 2%, it adds needed lubrication to ultra-low sulfur diesel. Diesel engine manufacturers have approved the use of up to 5% biodiesel with no reservations about engine warranties. Many fleets use B20, and a number of others burn B100 with only minor modifications to the engine and fueling system.
Biofuels in the Yukon
There are a number of biofuel projects underway in the Yukon by both the Government and resourceful Yukoners.
The Energy branch is working with the Agriculture branch to test the feasibility of growing several biodiesel crops in Yukon.
The Energy branch is also helping to fund the conversion of a diesel-fueled vehicle to a waste vegetable oil-fueled vehicle using waste oil collected from local restaurants. While these systems are well established in southern climates, the pilot projects will test of the practicality of these biofuels in the North.