LEDs trip the light fantasic
February 5, 2010 by Nick Clayton · 13 Comments
Pedestrians walking along Princes Street tonight probably won’t realise they’re witnessing the latest example in a technological revolution that’s gradually becoming visible in every area of our lives. It might even help to save the world, or at least destroy it more slowly.
After 18 months of consultation four street lights next to the Balmoral Hotel have had their lamps replaced by LEDs from Dialight. It’s the first trial of its kind in Scotland.
LEDs – light emitting diodes – have enormous benefits and what could have been one serious downside for Scotland. In street lights they reduce energy consumption by an estimated 50 per cent while increasing lighting levels by a factor of four.
Their responsiveness also makes them suitable for additional energy-saving measures. In quieter streets they can work with proximity sensors so they switch on almost instantly so pedestrians feel safer, but without burning power when nobody needs them.
You probably know the other advantage of LEDs. For decades they’ve shown whether electrical devices are switched on. How long is it since one of those lights “died” on you? In a street light their expected life is seven years and they’re relatively vandal-proof.
And their potential disadvantage for Scotland? That comes from their low power consumption which means they produce less heat than other forms of lighting. This led to a real fear that snow would not melt on LED-powered traffic lights and put motorists in danger. In fact, even in parts of America with more severe winters than Scotland, designs to stop the build-up of mini-drifts have proved effective.
And the onward march of LEDs continues. At last month’s massive Consumer Electronics Show in Las Vegas many of the most desirable gadgets featured screens made from “organic light emitting diodes” (OLEDs).
Compared with the LCD displays used for most televisions, computer monitors and mobile phones OLEDs have enormous advantages. They don’t need backlighting so displays can be thinner and lighter. They need less power and they look better with blacker blacks and a greater contrast ratio.
There are problems as well. OLED displays degrade relatively fast and unevenly so colour balance can be lost and screens can burn in, leaving a ghost effect. More importantly they are very expensive, Sony’s XEL-1, which just has an 11-inch screen will set you back £3,500. But prices will fall.
OLED technology is also being used in some novel ways. A Welsh company Lomox has developed LED wallpaper which it says could start to replace light bulbs by 2012. It’s reportedly 2.5 times more efficient than standard energy-saving bulbs and produces a more natural light. If the claims are true it could really revolutionise the way the world’s living rooms look.
And if the people sitting in those living rooms are turning down the light with a dimmer switch to watch a movie from a DVD player they can thank one man for all of them. Nick Holonyak Jr invented the first practical LED in 1962, the first household dimmer switch and in 1977 fabricated the first laser on a chip.
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I had always believed that the energy consumption by street lighting was largely immaterial, as what is used, is mostly, surplus night electric, generated by the nuclear and coal plants, which would otherwise go to waste.
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Fantastic!
But… 18 months of consultation? EIGHTEEN MONTHS? To replace FOUR BULBS?
Is it just me, or do we need a new approach to decision-making?
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Very nice. Much better illumination than before.
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We’re a very long way from home and dry when it comes to using LED technology for general lighting purposes. We are seeing serious increases in light output, but that doesn’t come either easily or cheaply. The driver technology in order to make use of those high-powered LED units is in its infancy and prices are astronomical. Colour temperature considerations are very real when it comes to domestic use.
Yes, the LED revolution has arrived, as far as indicator lights of many different sorts are concerned. And it’s arrived as far as torches are concerned, now that manufacturers have realised that LEDs really need some means of directing the light in a useful direction. OLED screens have been around for years, though there are questions with regard to longevity. The revolution is on its way with regard to automotive use where vibration resistance is of great importance. However we haven’t yet seen anything practical for domestic lighting on a serious scale. If it’s not practical uptake will be very low.
It’s interesting to observe that the withdrawal of many patterns of GLS light bulbs without adequate substitutes has within the last few weeks resulted in a rash of adaptor kits to allow assembly (by the end-user) of substitute lamps using quartz-halogen bulbs. Consumers will need to be satisfied that new lamps meet their needs before they’ll adopt them willingly.
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Stopped off to have look last night, the illumination is great at least twice that of the same size lamps they replaced, very clear and bright light, it certainly makes the dark quiet area feel safer.
Looking forward to a lot more of these around.
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If they produce 4 times as much light then will they produce 4 times as much light pollution?
I’d remove at least 1 third of all the street lights in the city. YOu don’t need to be able to read a newspaper at 2 in the morning when walking down the street. All you need is enough light to avoid falling over. The brighter the light ehdeper the shadows. And the higher the crime levels.
And why put lights on motorways? My car has lights on it. I don’t need orange overhead lamps. That’s a waste of resourses.
Low energy lighting is good.
Dark skies are better.
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I’m with you PeterG,
Why allow shops to leave lights on all night and then bleat at us for flushing our toilets twice as they fly overhead with their flying bomb machines (I live nearish to Leuachars, audibly active this last few days and nights) and dare to wash my tatties in warm water.
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Me too.
Bring back night time.
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As I understand it the light produced from these LED lamps is more focused and should leak less than conventional street lighting. There is definitely a separate debate to be had on how much public lighting is required and where.
We’ve relatively recently become accustomed to the idea that any major building should be floodlit. At the same time the area covered street lights has grown considerably. But, can you imagine Edinburgh City Council deciding to switch off the illumination of the castle because it’s expensive, polluting and serves no real practical purpose?
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Lighting is important towards creating environment.
These new lights sound like the way forward in lighting up our city centers making them more user-friendly.
But I have to agree with Mark above. “After 18 months of consultation four street lights ….”
“consultation” sounds expensive and 18 months excessive.
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There is a problem with LEDs — namely, their degradation over the first few months of operation. They may look great at the moment; but in six months time, they may have lost as much as 50% of their illumination…unless the company that’s installed them has adopted the technology which gradually increases the power to the lights over time. It’s a problem that some of the CCTV manufacturers have spent a lot of time solving.
LED is a great concept which are very useful in the right place. But there’s still some way to go before it will be really effective for street lighting.
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@David Calder.
Nonsense, LEDs degrade to 70% of their initial brightness after 100,000 hours. This is actually when they are considered to have failed even though they are still working.
Read page 7 of this: http://www.philipslumileds.com/pdfs/RD07.pdf
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I agree. LEDs do represent a technology that’s still developing and it’s not some ’silver bullet’ to provide low-cost, low energy light everywhere. What’s interesting is 48 years after its discovery there are still major advances being made and problems being solved. It wasn’t so long ago that you could get LEDs in any colour so long as it was red. OLEDs are becoming more stable, but their price is still too high for Apple to use as the basis for the iPad. (It was considered.)
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