GreenTech

Bright LED’s not available yet for street-lighting

Nowadays we don’t stand still with the development of LED lighting, because it’s in allot of daily applications such as the back-lighting in many laptops, tablets and naturally smartphones. This widely popular invention got the 2014 Nobel prize in physics awarded to Japanese scientists; I. Akasaki, H. Amano and S. Nakamura. LED lighting is durable and energy efficient. However why is it that people haven’t switched from conventional lighting to LED’s? In this article we answers this and what possibilities lies ahead for future LED applications.

In the last few years LED’s are widely being used in our daily applications, such as the flickering Christmas decoration, in the back-light for LCD’s in smartphones, laptops and other gadgets. You can use them for car lighting an conventional household lamps.

Also, with blue-ray players they use a blue LED laser instead of an infrared laser which is used in regular DVD players. This blue laser makes it possible to store 5 to 10 times more data according to C. Wetzel, a physicist at Rensselaer Polytechnic Institute in Troy, New York.

LED’s could have a positive effect on the society, because people of third world countries can have lighting off the grid with a LED light combined with a rechargeable battery and a solar cell. Another important factor is that LED’s purify water directly at the faucet, turn on/off, which results in lower costs. At this moment only a few companies are working on LED water purification, but in a few years it could be everywhere according to physicist C. Wetzel.renee van wesepThe LED is a solid-state technology (ssc), which emits light from a piece of solid matter. That solid piece is the semi-conductor with LED’s and when electrons move around within this solid piece the LED lights up. You see the semi-conductor is made of a positive charged layer with holes and a negative charged electrons which floats around. When you put on the electricity it activates the negative charged electrons flow, which go through the positive holes and then you get light. Some of the light is trapped inside causing the bright light.

In agriculture scientist are experimenting with LED-colors to make their crops grow faster and healthy. Plessey is a UK leading expert in the manufacturing of lighting and sensing products and components and they developed Hyperion. Which will grow crops with a LED grow light and it’s available for all commercially grown plant varieties. Universities, research organizations and commercial growers work close with Plessey in the 60 UK based installations.

On 6 July 2015 the GrowWise Center from Philips opened her doors on the High Tech Campus in Eindhoven (Netherlands). This indoor farm facility uses LED lighting in order to do research on optimal growing conditions for fruit, vegetables and herbs. Some farmers are already commercially experimenting with LED lighting. Such as Koppert Cress in Monster (Netherlands) installed 16.000 squares of LED lamps in his greenhouse. Depending on what you plant the LED colors are suited to optimize the result.

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Philips GrowWise center in Eindhoven.

With led lighting you have pro’s and con’s and through recent development in costs, efficiency and output it opens up the market for large scale production. The costs per light bulb goes down. For example at the University of Cambridge  in England they use silicon wafers to grown semiconductors which resulted in a dramatic manufacturing cost reduction. They hope to reduce the future price with 50%.

First, you have the advantages of LED’s. Which are: they are instant on, unlike compact florescent bulbs, you have a wide variety of colors available and cooler in operation. But the most important advantage is that LED lighting can be used to battle environmental issues, because compared to an incandescent s lamps they reduce Co2 output with hundreds of dollars.

It’s all because LED’s are time and energy efficient. For example a 60 watt incandescent bulb uses 525 kWh a year. Not only saves it energy, time is also an important factor. Incandescent bulbs last 750 hours and their Geobulb counterpart lasts about 30.000 hours. Technological development in this field made it possible to crick LED’s efficiency up to 50.000 hours.

Lastly LED’s doesn’t make use of toxic mercury and other toxic material with a blue tooth connection lights can be customized and you can uses them to transfer data through LiFi. You can incorporate sensors with LED’s in order to switch on/off the lights when someone enters or leaves the room. Scientists are now exploring the potential to transmit data from the internet across an open space with LED’s . Because of the speed of light they will be able to transmit data faster than WiFi. 

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Before and after LED lighting in Brundidge (US)

With the many pro’s you also have a few big con’s. The first one is high upfront costs, which aren’t always available for the masses. One LED bulb costs can be equivalent to ten’s of incandescent light fixtures. However, it’s an investment in the long-run, because you save energy and time.

And although the picture looks pretty rosy about what scientists say about LED’s research indicates that some wavelengths may damage the eyes over a period of time. According to a recent study by Complutense University of Madrid LED’s emit high levels of blue radiation. And according to Dr. M. Babu, an American medical Association board member;”Despite the energy efficiency benefits, some LED lights are harmful when used as street-lighting.”

The AMA gives the guidance about potential harmful health effects from ”improper” LED lighting. This helps local US governments to choose LED street lighting. According to the organization medical experts LED’s emit too much blue light, which may cause the disruption of sleep, the suppression of melatonin and intervening with the body’s circadian rhythm.

Researchers of the Mid Sweden University compared the effects of caffeine and blue light on the brain. They found out that blue light ex posers performed better and positively influence us such as on alertness. According to professor R. Stevens from the University of Connecticut the color temperature of lights at night must be no more than 3.000 Kelvin. LED’s produce light at the same frequency as sun light and the brightener the LED lights the more blue it emits. Incandescent lights are 2.400 Kelvin and some cities such as New York and Seattle have street lighting of 4.000 or 5.000 Kelvin.

On the flip side B. Qureshi a London Eye Hospital consultant ophthalmologist it takes a huge increase in LED use to cause permanent damage, such as is concluded according to the Madrid study, which tested a person with a 1000 watt light bulb for 12 hours a day at a distance of 12 inches.

For the latest insights and news in the LED industry: (ledsmagazine.com) The yearly Anaheim convention in Calafornia USA from 28 February – 2 March 2017,(strategiesinlight.com)

Sources

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  • Cossar V.M.,LED lights: Should we worry about damage to our eyes?, Internet, 9 December 2013, (metro.co.uk)
  • Hawkins, A.J.,Lexus covered a car with 41,999 LEDs to create the most phantasmagoric ride ever made, Internet, 5 December 2016, (theverge.com)
  • Harris, Jim, The LED lighting revolution, Internet, 2 May 2016, (ibmbigdatahub.com)
  • Jin, J.,Plessey to Showcase LED Grow Lights At IPM Essen in Germany, Internet, 16 December 2016,(ledinside.com)
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  • O’Hare, R.,Are LED street lights damaging YOUR health? Doctors warn the bright lamps could cause sleep problems, Internet,22 June 2016, (Dailymail.co.uk)
  • Unknown,BrightBox research Centre Venlo, Internet, Consulted on 25 January 2017, (lighting.philips.com)
  • Unknown,Philips opens GrowWise Center to advance LED growth recipes, Internet, 28 August 2015, (lighting.philips.com)
  • Unknown,Osaka Prefecture University, Internet, Consulted on 25 January 2017, (lighting.philips.com)
  • Unknown,Tuinder Westland gaat over op knalroze led-lampen, Internet, 6 January 2017,(nos.nl)
  • Zhang, S.,How LEDs Are Making Weed Better, Internet, 15 Oktober 2015 ,(Wired.com)

 

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