Today I want to give a short insight, what Lighting Designers and we, as Lighting Industry can do for Dark Sky.KL
I think everybody here has allready seen a lot of documentations from several institutions and from a lot of People dealing with unwanted light. I will not talk about zoning systems, I will not talk about definitions and limitations.
Documentations, lectures about the results from lighting installations, which protector is better, flat glass, deep bowls, which reflector and so on is better, I think there is some good information availlable and diskussed a lot.
KLIn summary, if there is a lighting instalation, there will be not only the wanted effect of lighting the Road Surface, but there will be some spill light on the souroundings, facades, into the nature ...
The results are the three phenomenas listed here.KLGlareKLObtrusive lightKLSky glowKLI do not want to get into the effects point by point now. The summary shows, the effect is simply said a waste of energy. And so it is not only light pollution, it is the production of greenhouse gases too.KL I know THE solution for a dark Sky. KLNo lighting at all, dark curtains at the windows and so on, just switch off all the lights. No sky glow, no light pollution any more.KLBut the lighting deals with the safety for drivers, for pedestrians, simply, it deals with the safety for People.KLSo Road lighting is necessary.KLLighting of working places about the exigence we need not to discuss. About the way to provide the right lighting this could be a separate lecture. KLAnd to talk about Sports lighting, there is the same, as before, a separate lecture. And sports lighting is also a social topic. It is better to know, that our children are on the sports place, then anywhere else.
And what is about facade lighting, effect lighting? I will come to this later. So the main target is, just to find the lowest level to comply the Standards. And of course, we have to satisfy the customer. But we can help him and find the right solution for his purpose.KLStandards for Road Lighting, 13201, and locally the O-1051 for pedestrian crossings and conflict areas, KLSports Lighting EN 12193KLand working places EN12464.KL For facade and effect lighting, there is no standard in Austria there it makes no sense there are only Standards and regulaqtions with restrictions, so I put it into brackets.
Standards show the State of the technology and shall be seen as minimum requirements to do it right.
From now on, I will mainly talk about road lighting, the main polluter in the case of light. Sport lighting is a question of the dose over the year, this is small. Working places there is the focus absolut on the right light for the working place. So there is only small place for discussions.
To find the right level, we can use the standards. KLBut we shall try to prevent from overlighting. This is for example the success from Schrder in the austrian market. KLFinding the exact right dose, reducing the power consumption through betterKLlighting desing and technology, to go as close as possible to the limit.
KLWhat do I mean with Use the informations needed for Lightingdesign.Here I have to talk a bit about the way to find the lighting class needed for a road lighting situation.
We have a lot of things that interacts with the class needed. This is given and defined in the Standard EN 13201.E.g. for a lot of road lighting installations, there are parked vehicles or objects that increases the complexity of the visual field resulting in a higher lighting class. Higher lighting class means more power consumption, more light, sometimes more luminaires and so on.KLIt is very easy to reduce the light level if there is a complete new road under construction. KLJust with the knowledge what can be done to reduce the light level from the beginning, everything can be optimized. If you prevent from having obstacles on the road, giving the driver a very simple situation for driving will result in a lower lighting level to fulfill the standard.And if there comes the argument with the driving speed and possibilities to reduce the average speed just place a radar box there, the investment of each Radar box have a short pay-back time ...KLAnd it is clear to try to find the best Lumianire availlable for the project and to do the lighting design as good as possible to prevent from overlighting.
Now let us talk about other possibilities to reduce lighting levels linked with reduction of Sky Glow.KLRoad lighting increases security on the road. KLAnd everybody knows, the better the lighting comfort, the safer is the traffic on the road.KLBut to increase the comfort, you do not need to increase lighting level. You have to increase the quality.To see objects on the road, our eye needs a minimum portion of contrast between the object and the road. And we know, the better the uniformity and the lower the glare, the lower light level is needed to get the minimum contrast level. And glare control means lower light pollution.
So there is the Idea, if the uniformity is much better as given from the standard, there shall be the possibility to reduce the level. KLKL E.g. Class ME3c means 1cd, Overall Uniformity of 40% and longitudinal uniformity of 50% and a TI with maximum of 15% that is giving a dedicated comfort.KLIf we increase the longitudinal uniformity to better 70% and reduce the TI to 10% or lower, we will get a better visibility than with ME3c with a lower light level e.g. 0,75cd.KLSo we do not have exact data from research in this direction, this shall be an Idea for starting the research needed. Fact is, the lower the glare, the better the uniformity, the lower is the lighting level needed. How much we can save with this has to be explored.The results has to be added into the standards.
So, what has to be done?KLAs first point, we will need some research, about the positive influence from uniformity and low glare to the contrast and how far can the level be decreased to get the same visibility as with the higher level but with lower uniformity and higher glare.KLOf course, the results has to be implemented into the standardsKLThe result can be a better comfort with lower light levels combined with less sky glow.
KLThis sounds perfect, doesnt it? I think this shall be a target to follow.
What is going on at the moment:KLThe new Standard for Light Pollution is under development. The O 1052 it shall be finished till mid of 2009. KLIt is more complicate, as thought at the beginning, so there are a lot of people involved to get the standard right.KLSo KLli