Matters of Scale - The Hidden Cost of Embodied Energy

Matters of Scale Image

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Energy used to heat a conventionally built house in Vancouver, Canada, for one year
101 million Btu
Energy used to make and transport the materials to build that conventional house (embodied energy)
948 million Btu
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Energy used to heat an energy-efficient house in Vancouver for one year
57 million Btu
Energy used to make and transport the materials to build that energy-efficient house (embodied energy)
1,019 million Btu
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Therefore, total energy used to build and then heat a conventional house in Vancouver as of the end of its first year of occupation
1,049 million Btu
…and total energy used to build and then heat an energy-efficient house in Vancouver as of the end of its first year of occupation
1,076 million Btu
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But…total energy used to build and then heat a conventional house in Vancouver as of the end of its 30th year of occupation [948 + (30 x 101)]
3,978 million Btu
…and total energy used to build and then heat an energy-efficient house in Vancouver as of the end of its 30th year of occupation [1,019 + (30 x 57)]
2,729 million Btu
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Energy required to produce one cubic meter of air-dried lumber
1.2 million Btu
Energy required to produce one cubic meter of plywood
9.4 million Btu
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Energy efficiency of a one-mile urban trip by a 2003 Honda Civic, in miles per gallon
32 mpg
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Energy efficiency of a one-mile urban trip by bicycle, when the cyclist is fueled by meat (which contains the embodied energy required to produce and transport one mile’s worth of meat energy to the cyclist’s home), according to one analysis
31 mpg
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But…energy efficiency of a one-mile urban trip by bicycle when the cyclist is fueled by bread
300 mpg
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Sources: Vancouver houses, embodied energy and one-year operating energy: Tracy Mumma, “Reducing the Embodied Energy of Buildings,” Home Energy Magazine Online, January/February 1995; Vancouver houses total energy use after one and 30 years: Worldwatch Institute; air-dried lumber and plywood: Andrew H. Buchanan and Brian G. Honey, “Energy and carbon dioxide implications of building construction,” Energy and Buildings, 1994; Meat: Michael Bluejay, “Bicycling Wastes Gas?” at BicycleUniverse.com, 2004.