A couple years ago I came across this new cycling route in Nuenen near Eindhoven made by one of my favourite Dutch artist Daan Roosegaarde (figure 1). He used pieces of a material similar to “glow in the dark” in the asphalt to light the road when night falls. This artwork made me wonder whether there are more innovations in street lighting ready to light the way in reducing our energy consumption. Eindhoven was also the experimental ground for another innovation: a sustainable smart lighting system (Braw, 2014). Their LED light system manages the streetlights with computers. This combination enables it to control each lamppost individually and regulate the light intensity and colour. Depending on the activity in the street and requests from residents for a certain ambience, the light can be adjusted. It even has the ability to remember residents regular routes.
Another Dutch start up investigating adjustable light intensity is Tvilight. They developed a motion sensitive system in which can turn on the lights and dim again when nobody’s around. This saves huge amounts of energy while still giving users a well lit street when they need it (Braw, 2014). Dimming street lights has become quite a popular idea in saving energy and for good reason. Globally more than 280 million street lights were installed in 2014, consuming 8% of all electricity and produced 5% of the greenhouse gasses (Ocana-Miguel et al., 2018). This crusade of enlightenment is predicted to cost between $23.9 billion and $42.5 billion by 2025 (Ocana-Miguel et al., 2018).
A study done by Beccali et al. investigated the results of different dimming methodologies (2015). They consider three different scenarios were considered: first, dimming ordinary street lights between 17:45 p.m and 05:45 a.m. during winter and 20:00 p.m. and 05:00 a.m in the summer. Seconde, LED were installed with cut-off optics. The third scenario combined the two. Conclusively, they found that the third scenario achieved the most reduction, as depicted in figure 2.
Dimming the lights is not our only option to cut emissions, as demonstrated in Copenhagen at the United Nations Climate Change Conference. They lit the streets using solar energy harvested by solar panels on the lamps (Yoneda, 2009). The producers even claimed these street lights could produce more electricity than they used. While Copenhagen looked towards the sun for energy, Theresa Harmanen saw potential in trees (Pham, 2012). She had the illuminating idea to collect the energy used by trees to maintain a pH-balance between itself and the soil to power motion sensitive LED.
Thus far, changing the lights has been focused on decreasing our energy consumption. However, ecological effects are also important to highlight. It has recently come to light that streetlights can disturb some natural processes and habitats that depend on the darkness of the night, hence the term light pollution. In a paper by Gaston et al. several options are mentioned to minimise light pollution, yet still satisfying safety concerns (2012). The first option offered is maintaining natural unlit areas, introduce structures to provide shading or removing light sources. This will provide some areas for night creatures where they can escape the light. I think, especially in the Netherlands, we also could remove most of the lights placed alongside of the highway. This since all cars have headlights that are perfectly able to light the road ahead, this could already save huge amounts of both light pollution and emissions. However, its implication is limited and this will only be beneficial for local species. Migrating animals will still encounter light or skyglow, which can be harmful for them. Skyglow is according to Gaston et al., 2012 “the increased night sky brightness that is produced by upwardly emitted and reflected electric light being scattered by water, dust and gas molecules in the atmosphere”, as is depicted in figure 3.
The next solution mentioned is turning lights off at certain times, as is also mentioned above. The ecological benefits are still a research topic, but it is expected that in this will positively influence the affected species. A shining concept using this knowledge is that of Civil Twilight. Here the the intensity of the moon is measured and the street lights will adapt their luminosity, see figure 4 (Design To Improve Live, 2009). Therefore, these lights will not disturb natural cycles that are depended on the moon, for example the hatching of sea turtles where they mistake streetlights for the moon which they use to orientate themselves towards the sea (Design To Improve Live, 2009).
To reduce skyglow Gaston et al. suggests another possibility, improving lighting design (2012). This because some of the light produced by the lamp is emitted in unwanted directions, creating skyglow. The last solution mentioned is adjusting the light spectrum in lamps. This because different species visual systems are sensitive to different wavelengths and behaviours of animals can be influenced by different wavelengths. This idea was incorporated in a pilot project was launched in Zuidhoek Nieuwkoop, near a natural reserve, bat friendly lights were installed (Cooke, 2018). The red LED lighten the road for humans, but are still perceived as darkness by bats (Cooke, 2018).
Personally, I think this could be a great way to brighten up our so far gloomy looking future. There are some truly great ideas out there that could both cut our energy consumption and decrease the light pollution. Therefore, making the switch from traditional lights to these advanced system is not only be beneficial for us, but also for the environment. Hopefully, these ideas mentioned will be implemented at large scale and maybe there is a sustainable light at the end of the tunnel.
Figure 1: Roosegaarde, D. (2015). Van Gogh Path [Picture]. Retrieved from https://www.studioroosegaarde.net/project/van-gogh-path
Figure 2. The depiction of the energy use of the three different scenarios compared to the base load during the months of the year. Reprinted from Beccali, M., Bonomolo, M., Ciulla, G., Galatioto, A., & Brano, V. L. (2015). Improvement of energy efficiency and quality of street lighting in South Italy as an action of Sustainable Energy Action Plans. The case study of Comiso (RG). Energy, 92, 394-408. doi:10.1016/j.energy.2015.05.003
Figure 3. An nine level the Bortle scale indicating the different luminosity of night sky at a particular location. International Dark-Sky Association. 2012. Fighting light pollution: smart lighting solutions for individuals and communities. Mechanicsburg, PA: Stackpole Books.
Figure 4. Illustrating the energy use of the new streetlight compared to different moon light intensities. Reprinted from Lunar-Resonant Streetlights (2009, April 30). Retrieved from https://designtoimprovelife.dk/lunar-resonant-streetlights/
Beccali, M., Bonomolo, M., Ciulla, G., Galatioto, A., & Brano, V. L. (2015). Improvement of energy efficiency and quality of street lighting in South Italy as an action of Sustainable Energy Action Plans. The case study of Comiso (RG). Energy, 92, 394-408. doi:10.1016/j.energy.2015.05.003
Braw E. (2014, March 12). Illuminating cities with sustainable smart lighting systems. The Guardian. Retrieved from https://www.theguardian.com/sustainable-business/sustainable-smart-lighting-systems-cities
Cooke L. (2018, June 07) Dutch town helps out rare bat species by installing “bat-friendly” streetlights [Blog post]. Retrieved from https://inhabitat.com/dutch-town-helps-out-rare-bat-species-by-installing-bat-friendly-streetlights/
Gaston, K., Davies, T., Bennie, J., & Hopkins, J. (2012). REVIEW: Reducing the ecological consequences of night‐time light pollution: Options and developments. Journal of Applied Ecology, 49(6), 1256-1266.
Lunar-Resonant Streetlights (2009, April 30). Retrieved from https://designtoimprovelife.dk/lunar-resonant-streetlights/
Ocana-Miguel, A., Andres-Diaz, J., Hermoso-Orzáez, M., & Gago-Calderón, A. (2018). Analysis of the Viability of Street Light Programming Using Commutation Cycles in the Power Line. Sustainability, 10(11), 4043. doi:10.3390/su10114043
Pham D. (2012, April 05). Theresa Harmanen’s ALMA Lamp Is Powered by Trees [Blog post]. Retrieved from https://inhabitat.com/theresa-harmanens-alma-lamp-is-powered-by-trees/
Salata, F., Golasi, I., Bovenzi, S., Vollaro, E., Pagliaro, F., Cellucci, L., . . . Vollaro, A. (2015). Energy Optimization of Road Tunnel Lighting Systems. Sustainability, 7(7), 9664-9680. doi:10.3390/su7079664
Yoneda Y. (2009, December 03). Path to COP15 Will Be Lit by Solar-Powered Street Lamps [Blog post]. Retrieved from https://inhabitat.com/path-to-cop15-will-be-lit-by-solar-powered-3xn-gotham-street-lamps/