First assignment of group n° 144



Resources used by the team


Book : The Principles of Green Urbanism, S LEHMANN



Book : Eclairage public : quelles solutions pour réduire la facture énergétique et la pollution lumineuse ? - R. Boughriet


Anne-Sophie EKOULE

Book : Rifkin, J. (2011), La troisième révolution industrielle, Editions Les Liens qui Libèrent



Book : Benyus, J.M. (2011), Biomimétisme: Quand la nature inspire des innovations durables, Edition Rue de l'échiquier



Book : Anderson, C. (2012), Makers: La nouvelle révolution industrielle, Edition Pearson



Book : Radjou, N. Prabhu, J., Ahuja, S. et Boillot, JJ (2013), Innovation Jugaad. Redevons ingénieux !, Editions Diateino



Book : Sempels, C. and Hoffmann, J. (2014), Sustainable Innovation Strategy, Palgrave Mac-Millan.


First description of our project

First description of our project's idea
Provide a proposition of title for your project

How to avoid energy losses in the big cities and consequently to reduce lighting and energy costs?

Please answer to the three expected questions:
1. What Problem do you want to solve ?

Light pollution is one of the less known. However it has major consequences on the environment, economy, health and science.

Indeed, street lighting emissions in France is about 670 millions kilos of dioxide carbon per year that is to say 21 kilos per second. Approximately 9 millions street lands are used to light French towns and countryside, that represents a consumption of 1.260Mw equal to nuclear reactor consumption according to the Ademe. Streetlight constitutes for little towns about one quarter of the global energetic bill and 38% of their electric charges. And for most of actual street lamps, 30% to 50% of light energy is lost because it going to the sky.

In 2008, the Ademe explained that modifying and adapting existing equipment’s could reduce by 40% street light charges.

Actually, overuse of lights has many negatives consequences in many fields:

• Astronomy: Astronomers are no longer able to work in urban areas because a low sky brightness is necessary for their research. Moreover, in the big cities of the world about 97% of stars are no longer visible. Thus, Canada's largest observatory, the David Dunlap Observatory, was forced to stop its observational activities because the still increasing brightness of the Toronto skyline has compromised its activities.

• Economy: public lighting is an energy and financial waste. Public lighting represents 23% of overall energy bill and 38% of the electricity bill of cities.

• Environment: biologists and environmentalists agree on several negative impacts related to the disappearance of the darkness. Plants need darkness, which determines their functioning and development. Excessive exposure to light can affect the germination, growth, leaf expansion, flowering and fruit development. Migratory birds are particularly affected by light pollution because they are confused by these light sources. Moreover, artificial lighting disrupts the life cycle of animals and men.

• Health: The World Health Organization has recognized that the disruption of the biological clock can cause many health problems, from insomnia to cancer through depression, diabetes and obesity. This disorder is often linked to a lack of melatonin secreted when we sleep, in the complete absence of light. It is therefore important to minimize the amount of light in our sleeping environment to minimize intrusive lights to avoid disturbing our biological pace, which is essential for health.

2. Why does this problem exist?

The second industrial revolution is characterized by the increasing production of electricity. Consequently, electricity and lightings are associated with a sign of progress. Nowadays, public lighting helps to reduce the feeling of insecurity in the streets. A great public lighting has to show security and safety for all who walks thought the streets or works at night. However, it is incorrect to associate a bright light to safety or the contrary to danger. For example, some cities, with the aim of reducing the light waste have decided to switch off the lighting between 2 a.m and 6 a.m, but these approaches are not conclusive. In fact, the population has a lack of confidence and a sense of insecurity. In the largest cities in the world, lighting is even used for decorative and aesthetic purposes. In France, 9 million lamps are used in cities and countryside, representing 1260 MW, the equivalent of a nuclear reactor. Each country starts to realize the importance and urgency to solve this problem. They are thinking of making solutions for reducing consumption. As an illustration, France passed, in 2013, a law to make energy savings. The concept is to switch off public signboards between 1am and 6am. Unfortunately, this law is not applied by all cities. In general, 30-50% of public lighting are completely lost. Why? Because it goes to the sky! Most lamps discharge 60% of the production of light to the sky. Public lighting, for townships, represents almost 23% of their energy bill and nearly 38% of their electricity bill. There is still much progress to be done and the potential to reduce the pollution is around 60%. A great margin for improvement...

3. What breakthrough are you commited to creating?

We want to create a device which regulate the intensity and duration of public lighting emitted by the streetlights. This device will adapt to the ambient brightness and settings decided by local authorities. We would like to create a universal electronic device that could adapt to any kind of bulb (led, sodium, mercury ...) and this at a lower costs. Indeed, in France, the cost of maintenance and investments are valued at EUR 1.2 billion. Thus municipalities have already invested heavily in new facilities and are not necessarily willing to invest again in expensive equipment. So the solution we propose will be possible for the various municipal budgets.

Potential experts already identified

Eglo, Philips, Smart&Green because they are lamp manufacturer and local authorities in order to have more information about street-lamp they already have. Homepage of the course