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LEDs & e-mail: False stories with long legs

Rick Nelson, editor in chief of Electronic Design News, recently shed some light on myths surrounding LEDs and e-mail.

LEDs: Solid-state lighting could increase the energy used for lighting by a factor of 10 within 20 years. Or at least that's what the New York Times said. The paper based its story on an article by Sandia researcher Jeff Tsao. Tsao wrote to explain to the Times that they misunderstood the entire article. The article had instead said that developing countries will drive substantial growth in the energy used for lighting over the next two decades, regardless of what kind of the lighting technology they adopt. He then estimated that the increase in energy use will likely cancel out any savings from more efficient lighting technologies.

E-mail: Mother Jones magazine reported that Mathew Yeager, who is said to work in a British data center, calculated that sending a 4.7-Mbyte e-mail letter generates as much greenhouse gas as boiling 17.5 kettles of water, presumably based on the electricity needed to send that letter. The NYT and Boston Globe then repeated the story. After some number crunching, it turns out that it would take about 5.67 kWh to boil all that water. So, at $0.17 per kWh (average for Nelson's area of the country), it would take about $1 to get all the water boiling. Meanwhile, Gmail provides Nelson with almost 7,500 Mbytes of free storage. He posits that Gmail would be out of business if each 4.7-Mbyte chunk of that free storage cost it $1, nor would e-mail be so inexpensive if the energy it took to send a large e-mail cost $1.

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