Wednesday, 6 January 2010
Is there a downside to saving energy?
The New York Times reports that transport authorities in several U.S. cities are concerned about the safety implications of their rapid switch to low-energy traffic lights. These traffic lights, which uses LEDs instead of incandescent bulbs, consume only a fraction of the electricity of traditional lights. Incandescents, after all, lose about 90% of their energy as heat. When it comes to reducing emissions from the hundreds of thousands of traffic lights around the country, the switch to LEDs is good news.
But what happens when it snows? When snow falls on a traditional traffic light, the heat from the bulbs can usually melt the snow, keeping the light visible. LEDs, by contrast, are much cooler and much less snow melts away. As the Times reports, snow-covered LEDs can pose a safety hazard - last April, one person died and four others were injured when a pickup truck ran through a snow-obstructed LED traffic light and struck another vehicle.
Thousands of miles away in Nepal, households are confronting a related issue. Their new, energy efficient stoves waste less heat. This means householders can cook with less fuel and reduce costs and labour burdens. In the winter, however, their houses can get colder than normal - all that "waste" heat had been keeping the room warm.
There are many other examples where "waste" energy from appliances and equipment actually serves a useful purpose. Without careful planning, the more efficient alternative may neglect this service.
This does not mean that we shouldn't continue implementing energy efficiency programmes and cutting carbon wherever possible. However, it does highlight the importance of careful planning to anticipate these potential trade-offs and taking action to reduce their severity. This is already happening with LED traffic lights. Rather than reverting to incandescents, officials realised that the waste energy only provided an extra snow-clearing service for a handful of days each year, and that there were other alternatives available:
"Transportation officials have been dispatching workers with brooms to clear the lenses[...]They are also experimenting with a solution that is less labor-intensive and more permanent, outfitting some of the lenses with sloping snow shields to make it harder for snow to stick."
The transition to a low-carbon economy means we have to do things differently. Careful planning can help ensure a smooth shift and deliver maximum benefit.
(Carbon Clear website)