Light-emitting diodes (L.E.D.) devices are often touted as a greener, more cost-effective alternative to light bulbs, but a study from Sandia National Laboratories suggests that these devices are unlikely to decrease the world’s energy consumption.
Jeff Tsao and Jerry Simmons, researchers at the laboratories, pointed out that L.E.D.’s might even encourage more use of energy, rather than promote energy efficiency.
The researchers found that people have steadily used more light over the past three centuries. People have consistently spent about 0.72 percent of the gross domestic product on artificial lighting, regardless of how efficient and cheaper the type of light source used became, the study states.
For example, Britain used less than 10 billion lumen-hours annually back in 1700 by burning candles. But by 1900, more efficient gas lamps increased the amount of light used to 10 trillion lumen-hours per year. Even though new technologies were more efficient, people still use more light, countering the energy a particular technology would otherwise save.
And as L.E.D. technology becomes cheaper, Mr. Tsao and Mr. Simmons feared that this trend will continue. Affordable lighting could entice people to use more lights and consume more energy in the process, they said.
“Presented with the availability of cheaper light, humans may use more of it, as has happened over recent centuries with remarkable consistency following other lighting innovations,” remarked Mr. Tsao.
"Every time there is an increase in wealth, or income, and a decrease in cost of light, we consume more light," he added.
Mr. Simmons agreed, “It’s a tension between supply and demand. So, improvements in light-efficient technologies may not be enough to affect energy shortages and climate change.”
Energy efficiency is not enough to decrease energy consumption, he noted. Rather, enlightened policy decisions are also necessary to complement energy efficient technologies to make a big impact.
This situation may cast a shadow over L.E.D.’s green credentials, but it can also make them economically attractive. Increasing light consumption will also increase productivity, as people will now be able to work at night.
The growth in productivity can add 1 percent to the world’s per capita gross domestic product by 2030, the researchers forecasted.
To answer the question of how much light is enough is quite difficult because no one yet has produced a gold standard for the right amount of light that would yield the best results, Mr. Tsao said.
Tomado de www.ecoticias.com