How does wood as a fuel compare with other sources in cleanliness?
Sources of Fine Particulate Pollution compares the quantity of particulate matter produced by various fuels and sources. It shows the number of grams of fine soot produced in an hour by home heating devices, recreational petroleum wax sawdust logs (they may contain other garbage as fuel also) and transportation. For comparison we also added thirty cigarettes to the chart. Agencies of the United States Government, and the Canadian and Australian governments promote the new wood stoves and fire logs to solve wood smoke air contamination. But their logic is flawed, as you can see in this chart.
By this we are asking what quantity of the fuel does it take to heat the house or cook the meal or power the lights. Solid fuels or biomass fuels are less efficient than oil, natural gas or propane. It takes larger quantities of peat, wood, or coal to do the job and they will produce larger quantities of smoke when they are burned. Solid fuels produce dramatically less heat for the amount of fuel consumed and produce dramatically more pollution. When we use more efficient fuels we produce less pollution. It is as simple as that. This has been described as the energy ladder. The dirtiest fuels such as grass and animal dung are at the bottom. Going up the ladder, step by step with wood, then coal, until the next most efficient type of fuel is used. Dramatic reduction in pollution occurs when the next physical state, liquid kerosene is reached. Liquid fuel is less polluting than solid fuel. Natural gas and propane are dramatically less polluting than solid or liquid fuels. Electric energy produces no at site pollution although it's generation does produce pollution. Wind, solar and hydropower are the cleanest forms of energy, as there is no combustion. Carrying the ladder analogy further, an Energy Pyramid symbolizes both quantity of fuel used and quantity of pollution produced going up the energy ladder. Say we do not know the number of grams that charcoal briquette combustion would produce. Charcoal briquettes are actually wood, initial combustion has burned off some of the start up pollutants. Thinking of the energy ladder we can place this cooking fuel in a pollution ranking because we know that it is in a solid form.
Burning Issues update: Nov. 11, 2002
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