Design Considerations
Last Update: October 30, 2010
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Sustainability

Buildings use 40% of the primary energy and consume 72% of the electricity in the United States (Environmental Information Administration, 2008) and produce the most global carbon dioxide emissions by sector (Environmental Information Administration, 2006) ahead of transportation and industry.

The carbon neutral concept, or having a net zero carbon footprint, is about eliminating carbon dioxide emissions in the process of operating day-to-day and then counterbalancing those carbon emissions that cannot be eliminated via offset purchases, such as investment in clean energy projects. Although carbon dioxide is the most abundant, it is not the only greenhouse gas (GHG) regulated by the Kyoto Protocol. These are:

  • Methane (CH4),
  • Nitrous Oxide (N2O),
  • Hydrofluorocarbons (HFC),
  • Perfluorocarbons (PFC),
  • Sulphur Hexafluoride (SF6), and
  • Carbon Dioxide (CO2).

“Climate neutral” takes into account these other greenhouse gases by expressing each in terms of their carbon dioxide equivalent impact on the atmosphere. Thus carbon neutral and climate neutral are often used interchangeably. See also Luminaires & Distribution/Luminaires & Sustainability.

Distribution of Carbon Dioxide
Sustainability Figure 1. Distribution of carbon dioxide at an altitude of 3.1 miles between March & May 2006. Image © NASA.
+ Click image to enlarge.

Embodied energy is the total energy required to produce a product throughout its life from raw extraction to end of life. That is the sum of the energy used to extract or create it, the energy to manufacturer it, the energy to transport it, the energy to install it, the energy to remove it, and the energy to dispose of it. Unfortunately, due to the quantity of components in an assembled product like a luminaire, it is more common to find data for individual materials than for a composite product. Embodied carbon is similar to embodied energy, only it is a measure of the total carbon dioxide emissions throughout the life of the product.

Transportation energy and carbon emissions can be a significant contributor to a luminaire’s embodied energy and embodied carbon. In the current global economy, luminaire component parts can travel around the world, perhaps even more than once, prior to reaching final assembly and then final installation. Transportation methods vary widely in their energy efficiency. For example, highway transportation by commercial truck adds more to embodied energy than the equivalent distance traveled by container ship. See Policies & Programs/Resource Efficiency for greater detail on embodied energy, including life cycle assessment (LCA), transportation impacts, embodied energy of raw luminaire materials, and an LED embodied energy example.

Although energy consumption and its associated pollutants has the greatest overall impact to the environment with regard to lighting use, there are other general sustainability issues to consider when selecting and specifying products and understanding the short term and long term impacts on our planet. These issues include:

Sustainability principles embrace social justice issues as well as environmental ones. This recognizes that our social structure well-being is as critical to human survival as the health of the natural environment. As Owners and the design community further embrace sustainable objectives, both contractor and manufacturer human resources and community practices are beginning to come under scrutiny as another evaluation criterion. Social justice issues encompass topics such as paying a fair wage, maintaining equitable employment practices, providing a safe and clean work environment, adopting reasonable work hours with adequate respites, respecting the native culture, and ethically disposing of waste materials.

Design Considerations

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