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Thursday, October 2, 2008

Is energy-saving lighting always best for the environment? | Energy Efficiency News

 

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Is energy-saving lighting always best for the environment?

Researchers from Yale University have found that switching to compact fluorescent lights (CFLs) may not always be best for the environment.

Energy saving CFLs are being implemented around the world in a bid to improve efficiency and tackle global warming. But CFLs have a downside – the bulbs contain mercury, which is extremely toxic and can lead to a variety of health problems. And that mercury can be released into the environment when those bulbs break or are disposed of through incineration or landfill.

CFLs are touted as a ‘green’ technology because their efficiency and long life time reduces both overall energy demand and the actual number of bulbs that need to be produced. A large portion of current mercury emissions arise from industrial processes such as coal combustion, so moving to CFLs should be a solution.

Concerns about potential mercury emissions have also led manufacturers to reduce the amount of the toxic metal in CFLs and adopt a voluntary code limiting mercury to 5 mg per bulb.

However, the Yale researchers calculate that there is a tradeoff between the reduction in mercury emissions through the use of CFLs and the emissions that are produced when they are disposed of.

Regions where coal is a major source of power and have an effective recycling programme for CFLs will benefit the most from their introduction. Parts of the US, China, and parts of Europe including Romania, Bulgaria and Greece would see great benefits from introducing CFLs.

However, in other areas such as California and many parts of east coast US the increased use of CFLs will actually lead to an increase in mercury emissions, according to the researchers’ calculations. Norway and most countries in Latin America, Africa and the Middle East could see a similar pattern emerging.

“CFL is an area where we’re really pushing this alternative and all these policies are being enacted, but we’re not looking at the potential unintended consequences of what we’re doing,” says researcher Julie Beth Zimmerman.

Unfortunately, many of the regions where introducing CFLs could have the most benefit in terms of reducing emissions from power generation are also those with limited recycling programmes.

“It’s always good to promote energy efficiency, but it’s also a tradeoff,” says graduate student Matthew Eckelman.

The researchers caution that nationwide or global strategies to ban incandescent light bulbs and replace them with CFLs could be too general and a local approach could garner better overall results.

For further information:
M. J. Eckelman, P. T. Anastas, and J. B. Zimmerman. Spatial Assessment of Net Mercury Emissions from the Use of Fluorescent Bulbs. Environ. Sci. Technol. (2008) doi: 10.1021/es800117h

Is energy-saving lighting always best for the environment? | Energy Efficiency News

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