LEDs are widely known for their great potential to reduce light pollution and energy consumption because of their relatively low costs and energy efficiency (Parnell, 2017). As such, LED technology has been a significant contributor in the “sustainable lighting” movement. However, the current extent of global light pollution illustrates a case of poor usage of these promising lights. Instead of reducing overall energy consumption, the benefits of LEDs have led to the excessive installation of artificial lights that led to the prevalence of light pollution. It is also interesting to note that some studies involving satellite imagery that captures and records light emissions of cities are not sensitive to blue light wavelengths that are emitted by LEDs (Parnell, 2017). This means that the severity of light pollution as a result of LEDs is likely much worse than we can visibly see! As a result of this rising concern of light pollution, this has led to the LED Paradox which reveals the juxtaposing roles LEDs play, where it is seemingly most energy-efficient yet concurrently the most ecologically unfriendly (Schulte-Römer et al., 2019).
A study adopting a transdisciplinary method on investigating the LED paradox offers insight into this dilemma from multiple perspectives. Approximately 250 respondents were categorised into 2 groups — the “lighting professionals” referring to professionals involved in the planning, designing and production of lighting technology and “light pollution experts” referring to astronomers, conservationists and social scientists who conduct research on artificial light at night (ALAN) (Schulte-Römer et al., 2019). Table 1 and 2 are the summarized responses from the study which provides explanations as to why LED worsens and prevents light pollution respectively.
Besides highlighting this LED paradox at a glance, the recorded responses also bring up an important factor about the effects of LED lighting. While it is not inherently good or bad, its application in local contexts and hence the design and installation process is the determining factor of whether it contributes to or reduces light pollution (Schulte-Römer et al., 2019). With that in mind, it is important to know how to use LEDs responsibly.
How then can we best utilise LEDs?
The International Dark-Sky Association has provided a list of suggestions to take into account when choosing lightings. These suggestions include:
- Choosing “warmer” or filtered LEDs that directly minimizes blue light emissions.
- Taking into consideration the higher luminous efficiency of LEDs and avoid over-lighting accordingly
In addition, considerations in choosing appropriate lighting to manage the effects of an overexposure of lighting include:
- Installing fully-shielded lighting fixtures or lighting fixtures that only illuminate desired areas
- Utilise adaptive controls such as lighting dimmers, timers and motion-detecting motion sensors
The use of such technologies enable light usage to be fully functional yet efficient. In addition, it enables flexibility in adapting lights according to its required function — dimming light intensity where applicable and turning light off when unnecessary. Altogether, it offers a simple response to the LED paradox!
Till next time!
Trudie
References:
- International Dark-Sky Association. (2018, October 24). LED practical guide. https://www.darksky.org/our-work/lighting/lighting-for-citizens/led-guide/
- Parnell, B. A. (2017, November 23). Good night to the night: LEDs are increasing light pollution, not fixing it. Forbes. https://www.forbes.com/sites/bridaineparnell/2017/11/23/good-night-to-the-night-leds-are-increasing-light-pollution-not-fixing-it/#2610067b69cf
- Schulte-Römer, N., Meier, J., Söding, M., & Dannemann, E. (2019). The LED paradox: How light pollution challenges experts to reconsider sustainable lighting. Sustainability, 11(21), 6160. https://doi.org/10.3390/su11216160