embodied energy and energy use

“Statistics are merciless things.” Le Corbusier, The City of To-morrow and its Planning, 126.

The Department of Energy has posted a lot of useful data on energy use in the United States, which helps identify the low hanging fruit for big gains in energy efficiency. Some of the key take-aways: Americans consume one fifth of the world’s energy. Two-fifths of that energy is consumed in and by buildings, with 22% going into our houses. 91% of that energy produces carbon or radiation. And, most depressingly, nearly half our energy is lost in transmission and distribution.

But beyond making the simple case for energy efficiency, renewable energy generation and on-site generation, the DoE data also help us evaluate the energy footprint of different construction methods. The embodied energy of different construction methods includes the production and transportation of materials, and their erection on site. Our steel frame, for example, accounts for about 5.5 pounds of carbon dioxide per square foot of building, which is just 14% of the embodied energy in South Florida’s more typical concrete block and stucco walls.

Another source for energy conservation is water conservation. The Buildings Energy Data Book includes data on the energy used to source, treat and distribute drinking water and sewer waste. We'll blog more on how water equals energy, and energy equals water, in the future.

[images from U.S. Department of Energy Buildings Energy Data Book]