Switching to CFL mode will cut emissions
2 Oct 2008, 1454 hrs IST,IANS
WASHINGTON: Yale scientists have found that certain countries will gain by using compact fluorescent lighting or CFL, more than others in the fight a
gainst global warming.
The study looked at all 50 US states and 130 countries to determine the impact of CFL on total mercury emissions in those regions.
Touted as a greener alternative to traditional lighting, CFLs are about four times more energy-efficient than incandescent bulbs and last up to 10 times longer.
This increased efficiency lessens the energy demand on generating stations powered by fossil fuels and reduces greenhouse gas emissions, as well as the amount of packaging and old light bulbs that end up in landfills.
But unlike incandescent light bulbs, CFLs contain mercury, a toxin with potentially hazardous effects that can be released during manufacturing and disposal.
Estonia, which relies heavily on coal-fired power generation, tops the list as the country that would see the greatest cut in mercury emissions for every incandescent bulb it replaces with a CFL bulb, according to an Yale release.
However, given its similar reliance on coal-fired plants, China stands to reduce its mercury emissions by the greatest overall amount. Other countries near the top of the list include Romania, Bulgaria and Greece; within the US, North Dakota, New Mexico and West Virginia have the greatest potential to reduce their mercury emissions.
But much of South America, Africa, the Middle East and parts of Europe, along with Alaska, California, Oregon, Idaho and several New England states, would actually increase their mercury emissions by making the switch from incandescent to CFL.
The results depend on a complex relationship between a number of factors, including how dependent a region is on coal-powered energy generation, the chemical makeup of the coal used in those plants, and existing recycling programmes for CFLs.
"Compact fluorescent lighting 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," said co-author of the study, Julie Beth Zimmerman, assistant professor in Yale's department of chemical engineering and its School of Forestry & Environmental Studies.
"It's always good to promote energy efficiency, but it's always a tradeoff," said lead author Matthew Eckelman, a graduate student in Yale's department of chemistry and the Centre for Industrial Ecology. "You may get a lower energy bill at home, but you don't see the emissions or the runoff downstream."
While the researchers stress that their study isn't an excuse to ignore the energy problem and stick with old, inefficient technologies, they caution that nation-wide strategies such as recent bans on incandescent bulbs, adopted by several countries including the US, may be too general.
The authors of the paper are Matthew Eckelman, Paul Anastas and Julie Beth Zimmerman, all from Yale University.
These findings appeared online in the Wednesday edition of Environmental Science and Technology.