Intelligent Street Lighting
Why Street Lighting?
Street Lights consume 350 GWh yearly, which means there is a great potential for optimising energy efficiency by replacing light sources. Therefore this is one of DOLL’s focus areas.
Within the next 2-3 years, Danish regions and municipalities have to replace outdoor lighting for up to €400 million. That gives a unique opportunity for achieving large energy savings, creating better lighting solutions and securing future-proof installations on Danish roads. In DOLL Living Lab these opportunities are explored among the 18 manufacturers who has displayed 50 different lighting solutions and in Quality Lab, where the quality of the light is measured and documented to enable decision makers to compare the products.
The LED technology is an evident replacement of traditional lighting sources because it is efficient and requires low maintenance. In combination with intelligent management of light, energy savings can amount to 70%.
The LED technology also offers completely new opportunities as to the way we use light. For example; by controlling street lights intelligently, it is possible to glare down to 10-30% of the intensity in periods of time with no traffic on the streets e.g. after midnight. When a road user enters the specific area, the lighting will increase the intensity to 100%, only in the area where the road is used.
Lighting with physical benefits
Energy savings and financial benefits are not the only things one should take into account when investing in new urban space lighting. Depending on the strengths of light, colour temperature and quality in relation to colour reflection, lighting can be experienced differently by various people.
Further, for financial benefits and energy efficiency considerations, one should take a stand on which function the lighting should fulfil, which types of urban space environments one wishes to create and how the aesthetic aspect turns out.
Lighting can be a very economically beneficial way of creating safety and comfort, giving urban spaces and residential areas their individual identity and fostering good traffic conditions for all types of users. However, these elements must be included from the beginning in order to be fully utilised.
Farewell to the mercury-vapor lamp
From 2015, marketing of the mercury-vapor lamps is prohibited in the EU due to more strict requirements for energy efficiency.
Since the 1960s the mercury-vapor lamp has been broadly used for street lighting and approximately 300,000 of them are still functioning on Danish roads.
The prohibition means that Danish municipalities are forced to invest in the replacement of lighting sources in much of the existing street lighting systems around the country.
There are several reasons for thinking of alternatives to the mercury-vapor lamps. Even if the lamp is inexpensive to purchase, it requires a lot of maintenance due to the high levels of power consumption (50 lm/W) and short longevity (10,000-16,000 hours). Moreover, the levels of mercury in the light bulbs are very high compared to other types of illuminates which provide the same amounts of light, and the quality of the light is very poor (Ra 60); it makes it difficult to distinguish colours in the gleam of the light.
The mercury-vapor lamps are also known as HME (ZVEI), HPL (Philips) and HQL (Osram).