YLP CPD Webinar: We share the night

Apr 6, 2022 | CPD, Industry, Webinars, YLP Webinar, Young Lighting Professionals

How do we re-think lighting in a way that has a lower impact on the environment, while still fulfilling human needs?

How do we implement our good intentions in real life?

Gladsaxe municipality needed a lighting solution that affected a nearby bat colony as little as possible, while maintain safety on the bicycle path running through a wooded area. Taking point of departure in this case, we discuss how lighting professionals should work to translate scientific research and technical knowledge into innovative site specific projects with the lowest possible environmental impact.

Speakers: Philip Jelvard and Rune Brandt Hermannsson, Light Bureau.

Hosts: Matt Fisher, YLP Chair and Toby Penter, YLP Vice Chair.


Flicker Free – what value are you targeting?

We are still following up on research on this, but have no real answer right now, unfortunately.

Other than ILP Guidance Note 8, what other standards or research do you typically reference when trying to determine environmental impact of a lighting design?

These are early days, but we try to do our researched case-based in cooperation with people who have local knowledge of the biotope in question.

Has any data been obtained from the area showing that bats are not exhibiting their light adverse behaviour to this lighting scheme or that this scheme represents a real improvement in terms of bat activity? Or is a case study currently being undertaken?

We have no good control study that we would be able to reference to see rather we have made any improvements. But we are in talks with local biologist to see whether they would be interested in doing some study in the area.

You mention in your ILP Lighting Journal Article that more time is required for the public to adapt the project. Have you received further public feedback since the article was written and how has the public responded to the installation initially?

We haven’t received much more feedback from the public and from the everyday users. But we plan on doing an onsite visit to get a better understanding of public opinion.

I’m all for the conservation issues touched upon in the presentations. However, I find myself, as a UK Lighting Engineer facing a dilemma. How do we address the environmental issues when the solutions would seem to contradict the demand for “better” lighting by the issue of Safety for Women (particularly at night), when the latter invariably means increased usage of white light at higher levels to help with CCTV and facial recognition etc?

That is a real dilemma and that should hopefully underline the fact that this particular scheme isn’t suitable everywhere.

we were comfortable in implementing a scheme with only red light. Would it had been elsewhere for-instance a public square a pedestrian path or a tunnel or underpass we would have been much more cautious about a scheme with only red light. Overall, we argue that a thorough analysis of needs for each project is needed, balancing the impact on the environment with human safety.

Research has shown that migratory bats are attracted to red light…appears a bit conflicting?

From the analysis of the local biotope, we received there was no mention of migratory bats thus were comfortable in implementing a scheme with only red light. Had there been any mention of migratory bats the scheme would have been different.

Has this project been assessed post completion? Are there any results of its effectiveness for people and bats?

Not yet, but we plan on making an evaluation on-site where we would like to ask commuters about their experience of the site after having used it for 6 months or so.

Was pure amber considered?

We considered a solution that would switch from more conventional warm white or even amber to red. But when we learned that the bats would be better of not having a changing lighting scheme that was the way we went.

There was a Dutch town lit in red for bats c.2018, was any evidence taken from this scheme or others?

Yes, we relied partly on their research.

What was the colour temperature of the lights you used?

It’s off the charts. We had it calculated and the specification sheet said 0K.

In terms of the carriageway and driving through the scheme, how does the lighting affect the drivers view of the carriageway ahead. Has the carriageway been calculated to comply with standards as the spill light from the footways in entering the carriageway? Does this open further risks of objects not being visible in the carriageway?

From the drivers point of view the levels of the red light is so low compared to the light coming from headlights of today’s cars that the road ahead will appear as you would be used to on an unlit road.

The lighting on the road does not comply with any standards, but this has been accepted by local authority to make the best scheme possible for the bats. In the areas where cyclists are crossing the road we are fully illuminating the roadway to make sure objects are visible, just like at a pedestrian crossing. Safety when driving a car in the dark is related to the ability to detect whether there is an object on the road in front of you or not, so it’s mostly about creating a contrast to the background. It is a very functional task not related so much to the shape of the object but more the fact that there is an object that you have to avoid.

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