Exterior Lighting at LightSave Summit

1 November 2010 | Updated: 21 December 2010 10:54 am

The LightSave Summit at BEST addressed two major issues that affect the industry. The first forum looked at exterior lighting, with experts calling for a better use of darkness. Richard Brass presents the discussion, sponsored by Abacus.

Phil Gardner: In the city of the future, when we’re thinking about low-carbon, what will we do with the need to light roads?

David Gibbons: With the advances in technology in the automotive industry and the lighting of cars, we could look at reducing the lighting levels in cities overall.

Kelvin Austin: We need to think about other ways of street lighting, because we’ve been using a lantern on the end of a column for the last 75 years. With the invention of LEDs, I don’t see any reason why street lighting can’t be built directly into the column, or even into the kerb.

Brendan Keely: We’d like to mount equipment on walls, on buildings and on façades. It would remove visual clutter and the need for a column, which could save money in manufacturing and delivery. If we could mount on buildings more often, it would also reduce the amount of light pollution that goes into windows.

Paul Nulty: We did a public square in Southwark a few years ago, and we lit it without a single column or bollard. I’d say embrace the darkness as much as the light. Consider how easy it is to use good darkness within a space.

Nigel Parry: I don’t have a problem with using darkness as the focal point of a city, where it works really well. But the local authority engineer has some responsibility for making sure that, when somebody leaves their house at night, they’re going to have a safe passage to and from wherever they’re going. Something we’ve been trying to push for years is to get major authorities to have lighting plans. If you go to bigger cities like Birmingham and Westminster, they have detailed plans and can tell you which alleyways should be lit to what level. Across the UK – not just local authorities, but airports and other places – should have a more joined-up approach.

Phil Gardner: There may be a plan, but who enforces it? From my own experience, I see an urban environment where maybe one shop or curryhouse decides to illuminate themselves, and then one further down the road decides to light theirs in a colour, so there’s a competing brightness. I don’t see many people from the local authority going down and turning their lights off for them.

Brendan Keely: For any retailer to have their lights on at three in the morning is absolutely pointless and it’s burning energy. What needs to happen is some sort of strategy or guide document for shops and stores. Maybe have the front window lit, but at night it doesn’t need to be as bright because it’s competing with a lot less natural light.

Phil Gardner: If a future low-carbon city has less light in it, is there any fear of going too far and the city becoming austere?

David Gibbons: You have to remember that there are many reasons for light. Safety, attractiveness, navigation; and there’s a real role for decorative schemes, which many people say are clearly a waste of energy. Things that we put in city centres are designed to make them unique, memorable, attractive, so people want to go back there. It creates landmarks where people can meet.

Brendan Keely: The best way of creating landmarks or icons is to reduce the ambient lighting around them, instead of making them so much brighter than their surroundings. It would be good to see some research looking at how far realistically we can get in terms of reducing light levels, for pedestrians, for cyclists and for road users as well.

Nigel Parry: I’m happy to suggest that the peak-time lighting levels on suburban streets are dropped by 50 per cent – or 20 per cent at other times – but maybe we could make controls a bit more interactive. We’re all starting to use smartphones now. Maybe looking to the future, if you get off a bus at 10pm with a smartphone, the system could pick up that you’re entering that street and raise the light levels for the walk back to your house.

Kelvin Austin: The idea of using iPhones to increase the light level or dim it down is perfect. I don’t see why we can’t do it now. The problem with dimming footpaths or other areas is that if they’re so dim, you wouldn’t want to use them. Interactivity – really working with the lighting – is fantastic.

Phil Gardner: What about white light? Is sodium dead?

Kelvin Austin: It’s going that way. You see better at night under white light at low luminence levels. But, as the brightness increases, when you get up to about 50 or 60 lux there’s no advantage. Certainly at the low lighting levels, from car parks downwards, I think everything will gradually turn to white light. But people are being very sophisticated about it.

Brendan Keely: In terms of white light the take-up is still slow, but the quality of the lit environment with white light is so much better. And we can still create distinctive areas by using colour temperature; different styles of lighting; different column heights; and different furnishings of the features themselves. So I think we can still create distinctive routes and differentiate between them with white light. I think if we do that, city and town centres could be far more attractive.

Paul Nulty: Getting local authorities and investors to put more money into reducing their carbon footprint is going to get a hell of a lot harder. We sit in meetings with local authorities, and they don’t want change. They want to use the same globular streetlight they’ve been using along pedestrian pathways for the last 20 years. We’re really asking for a change in mindset from local authorities and from developers.

Nigel Parry: We need to let the industry and local authority managers know the real costs involved. We have to educate, and say there are alternatives to just switching off. You do need to invest in some sort of dimming regime; you do need to look at the new technologies. Half the UK still uses SOX lighting, which is perhaps the most energy-efficient in raw terms, but if they change to LEDs they’re going to start saving energy in a year or so. LEDs can be dimmed, and energy could be used a lot more cleverly than it is now without any implications to society of increased accidents or increased costs.

Participants at the Abacus forum on exterior lighting:

● Phil Gardner, head of design, Greyblue Lighting Design

(facilitator)

● Kelvin Austin, principal lighting engineer, Abacus

● Nigel Parry, director, Array Lighting

● Brendan Keely, lighting design associate, BDP

● Paul Nulty, director, Light Bureau

● David Gibbons, Urban Projects