The switch to outdoor LED lighting has increased light pollution and power consumption – “The migration to LED isn’t having the anticipated benefit in terms of global reductions in energy usage”

Desdemona Despair

By George Dvorsky
22 November 2017

(Gizmodo) – To reduce energy consumption, many jurisdictions around the world are transitioning to outdoor LED lighting. But as new research shows, this solid-state solution hasn’t yielded the expected energy savings, and potentially worse, it’s resulted in more light pollution than ever before. [more]

Using satellite-based sensors, an international team of scientists sought to understand if our planet’s surface is getting brighter or darker at night, and to determine if LEDs are saving energy at the global scale. With the introduction of solid-state lighting—such as LEDs, OLEDs, and PLEDs—it was thought (and hoped) that the transition to it from conventional lighting—like electrical filaments, gas, and plasma—would result in big energy savings. According to the latest research, however, the use of LEDs has resulted in a “rebound” effect whereby many jurisdictions have opted to use even more light owing to the associated energy savings.

Indeed, as the new results show, the amount of outdoor lighting around the world has increased during the past several years. “As a result, the world has experienced widespread ‘loss of the night,’ with half of Europe and a quarter of North America experiencing substantially modified light-dark cycles,” write the researchers in the new study, which was published today in Science Advances. […]

“I expected that wealthy countries would appear to be getting darker (even if that wasn’t truly the case). Instead, we observed wealthy countries staying constant, or in many cases increasing,” said Christopher Kyba, lead author of the study and a researcher at the GFZ German Research Centre for Geosciences, in an interview with Gizmodo. “That means that even though some cities are saving energy by switching to LEDs, other places are getting brighter by installing new or brighter lamps (that need new energy). So the data aren’t consistent with the hypothesis that on the global scale, LEDs are saving energy for outdoor lighting applications.” […]

Disturbingly, the results presented in the new study may actually be worse than the data suggests. As previously mentioned, DRB is not able to detect low-wavelength blue light, which humans can see. Our planet, therefore, is even brighter at nighttime than the data suggests.

“This study is important because it validates with data two things we have suspected: that the rate of growth of light pollution continues upward on a worldwide scale, and that the migration of outdoor lighting from older technologies to LED isn’t having the anticipated benefit in terms of global reductions in energy usage,” John Barentine, the resident physical scientist for the International Dark-Sky Association, told Gizmodo. “The latter point is especially important because a number of governments have been convinced to convert their outdoor lighting to LED on the basis of promised reductions in energy usage.” [more]

The Switch to Outdoor LED Lighting Has Completely Backfired

ABSTRACT: A central aim of the “lighting revolution” (the transition to solid-state lighting technology) is decreased energy consumption. This could be undermined by a rebound effect of increased use in response to lowered cost of light. We use the first-ever calibrated satellite radiometer designed for night lights to show that from 2012 to 2016, Earth’s artificially lit outdoor area grew by 2.2% per year, with a total radiance growth of 1.8% per year. Continuously lit areas brightened at a rate of 2.2% per year. Large differences in national growth rates were observed, with lighting remaining stable or decreasing in only a few countries. These data are not consistent with global scale energy reductions but rather indicate increased light pollution, with corresponding negative consequences for flora, fauna, and human well-being.

Artificially lit surface of Earth at night increasing in radiance and extent