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100 Watt

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Overview “Floodlights”

Background

Floodlights used widely in a range of applications.  These lights typically use 150 to 400 Watt globes either HPS or less efficient halogen lights which not only use a lot of power but also have a bad power factor thus increasing costs.

Elexpert has developed an attractive  more efficient solution to this challenge.  This paper described the features thereof.

New Light Design

The basic idea of the retrofit LED floodlight is as follows that it is a single screw in unit like a conventional HID or halogen lamp. The basic light unit which includes:

  • A constant current power driver.
  • LED/s
  • PC board
  • Variety of lenses
  • Heat sink
  • Thermo switch
  • Cooling van.
  • A basic screw in structure.

The whole idea is that the light is modular.  If it fails it can be replaced under guarantee and only the faulty component be repaired.

Features of the light

The features of the new light can be summarised as follows:

  • Much more efficient use of electricity to provide the light. (70% saving)
  • Easy change of components.
  • Immediate light, not 10 minute waiting period.
  • Only 10% failure expected in more than 50 000 hours.
  • Excellent power factor.
  • Dimmable with leading edge dimmers.

The following will happen with light problems:

  • If the light or driver fails there will be immediate loss of light.
  • If the fan fails the thermo switch will cut supply when overheating.
  • Once the LED is cool, the LED will switch on again.
  • Such switching on and off will thus indicate a faulty fan.

Elexpert LED Lights

With the rapid development of LED lights, options are now becoming viable to displace the current inefficient lights.  A new light has now been developed which capture various features in meeting various customer needs in the market.  This paper sets out the features of the new LED lights with retrofit features.

Basically two options are offered:

  • For replacing 400 and 250 Watt HID lamps: Up to 90 Watts LED. The same unit can be set on the light at:
    • 90, 75 or 60 Watts.
    • E40 socket.
  • For replacing up to 150 Watts: Up to 30 Amps LED: Different units can be ordered to meet different needs.
    • 20 Watts, 30 Watts.
    • E40 or E27 Socket.

The picture below shows a 90 Watt unit with a 30 degree focus lens retrofit in an existing fitting.

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Retrofit

The idea of the retrofit is the following:

  • The old power supply and starter be removed.
  • The old globe be removed as well as the reflector. (important to air circulation)
  • The new driver be installed and 230V power connected.
  • The LED light be screwed into the existing E40 socket and be aligned.

The attractive feature of this is that no extensive construction work is required and the existing fittings can be used.

Maintenance / Failures procedures

One of the big challenges of new LED lights relate to maintenance / replacement.  Eventfully all lights will fail.  The cost at which many LED streetlights are being changed in South Africa is ridiculous.  Many of them will never reach break-even.  The following problems are thus being faced by customers in respect of the current complete LED lights:

  • They are faced with replacing the complete light in the future at an enormous cost.
  • They will have to keep complete units as spare. This is not just a small globe but a complete unit at high cost and taking much space.
  • When lights fail due to guarantee, old age, lightning or any other reason the complete unit need to be changed at high cost.

The Elexpert Globe approach overcomes all these problems as the cost is much lower as the light is a separate small interchangeable unit.

The maintenance on the light is very simple:

If the light goes on and off by itself:

  • The light is overheating. This will happen if the lights are on during the day (when day/night switch is faulty / bypassed).  Fix day/night switch.
  • This could indicates the fan has failed. Change the light with spare.

If the light goes off or dims:

  • This could indicate a problem with the driver or the LED.
  • Change the light with spare one.

To facilitate the process of fixing / exchanging faulty units Elexpert has made arrangements with courier companies to collect and return these to customers on site at a small fee.  It is recommended to buy some spare units as with HID lamps so that faulty units can be replaced immediately without having to way for replacements.

Light intensity

The 30 or 90 Watt LED light provides slightly less lumens that the 150 / 400 Watt HPS light but can be better focussed  to the areas that need most light.  This will enable good focus on the target area with least wasted light.

The comparative light spectrum for different lights are compared in the figure below for the 150 Watt HID light capacity.

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This shows that the Elexpert LED light provides more light in the horizontal axis but with less of a spread in the vertical axis.  This makes it much more efficient as a lot of light is wasted with other lights shining into the air and over exposing the area in the immediate vicinity of the light.

The comparative light spectrum for different lights are compared in the figure below for the 400 Watt HID light capacity.

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It is clear that the LED’s lights can provide the similar light as the HPS lights in the target area with much lower power.  With different lenses different focuses can be achieved to meet customers’ different needs.

Warrantee

The complete light (Globe) carry a 3 year exchange guarantee.

If any of the units fault after the guarantee period a fee will be charged to replace / repair the faulty components.

The customer will change any faulty units. If any of the units fault after the guarantee period, the same process will apply except that a fee will be charged to collect / install / replace / repair the faulty components.  It is important to note that only the faulty components will be replaced and be charged for.

Life Expectancy 

The life expectancy of the various key components of the product are as follows:

  • The Power supply. – 10 years continuous.
  • The fan. – 10 years continuous.
  • LEDs – 5 years continuous.

Lumen maintenance Lifetime.  The output of LED do reduce over time.  This is largely depending in the temperature of the LED.  The solution provided here will retain a surface temperature of less than 85° C.  This indicates that 80% light will be retained after 50 000 hours of continuous operation.

Break Even

The savings for customers will depend on the tariff applicable.  Most floodlights are used by private customers buying at municipal tariffs.  Calculations were done on the average price at the Eskom Megaflex tariff.  Municipalities typically charge more than 40% more than Eskom tariffs.  The expected break-even for the 2 options at a typical municipal tariff are shown in the tables and graph below:

image012 image014 image016 image018

The following can be concluded from this:

 

  • Breakeven is in less than 12 months after which significant profits will be achieved.
  • The 400 Watt light hold the greatest returns.
  • Companies who pay company tax can claim a tax rebate from SARS. The value of this is equal to about R230 and R560 for the 150 and 400 Watt lights respectively.  There are however measurement and verification costs involved which need to be factored in.  This can have a big impact on the break evens.

Why Change

The main drive for the installation of the new more efficient LED Streetlights are as follows:

  • Savings in electricity:
    • Lower usage of the LED light compared with other lights.
  • The ability to switch on and off in very short periods compared with Sodium Vapour.
  • Ability to dim the lights when there is very few traffic or say after midnight.

The new LED light with its power supply will use about 25% of the power of the existing light for similar usable light depending on the customers need.

This reduced electricity savings will off-course assist customers in the following respects:

  • Lowering their carbon footprint.
  • Moving towards achieving the 10% savings requested / required from key (eventually all) customers.

Conclusions

The new Retrofit LED Streetlight provides a first real affordable alternative to the high light intensity Sodium Vapour lights used extensively in South Africa.  It reduces electricity consumption by at least 70% and provides excellent return on investment.  The reduction in electricity demand offered by these lights can make a significant impact on the shortage of electricity supply in South Africa and a very significant reduction in impact on global warming.