Light Bulbs and Globes Compared

A comparison of LED, fluorescent and incandescent lights and their performance and efficiency

Standard Types of Light Bulbs or Globes

Let us look at the development of modern light bulbs

Incandescent tungsten filament lights

Incandescent, of course, means they work by electricity heating a filament so hot that it gives off white light but, unfortunately lots of heat as well.

Back in 1879 Thomas Edison was granted a patent for the first commercially practical light bulb, a design that, with a few modifications, has served us well for nearly 130 years.

His early production light bulbs had filaments made from carbonised bamboo and as time progressed the carbon filaments were replaced by far more reliable tungsten.

Halogen lights

Halogen bulbs have halogen gas inside the glass bulb which allows the tungsten to burn even hotter (and therefore brighter) than the ordinary incandescent bulbs. This also makes them fragile so jolting them while they are on or, more likely, fluctuations in the power supply can easily blow them and hence our problem.

The miniature halogen spotlights that have become so popular are known as MR16 lights. MR16 stands for Multifaceted Reflector with the 16 referring to the diameter of the front face in terms of the number of 1/8ths of an inch so an MR16 is, in sensible measurement, 2" or 51mm across the face.

Compact fluorescent lights

Over the past few years we have seen huge changes in household lighting as the old tungsten filament incandescent light bulbs have vanished almost overnight to be replaced by compact fluorescent lights. These produce less heat and are far more efficient but they do contain mercury. We can expect that compact fluorescents will be around for quite a while yet but many of us will soon be using LED lighting.

Light Emitting Diode or LED lights

LED (Light Emitting Diode) lighting has been around for a few years now but only recently have they become sufficiently developed to be considered a replacement for compact fluorescent lights.

In the early days of LED lights there was mass production of poor quality lights and the market was saturated with lights that had not been particularly bright, had poor colour and, worst of all, don't last very long. This flood of LED lights was also particularly frustrating in that many were designed with the light units built into their fittings so that if the light failed you would have to replace the whole fitting.

But now the game has changed, the lighting professionals have done some serious research and we are able to buy high quality LED lights that fit into standard electrical fittings.

Standard lightbulb types and the codes that identify their fittings

First let us quickly look at standard light bulbs or, more importantly, the fittings they go into:

The Quality of LED lights has dramatically improved

Some years ago I heard that Philips, noted for their very good light bulbs, had stopped all development of incandescent lights and were working on compact fluorescents. They went on to produce what are probably the best compact fluorescent light bulbs available with good warm colour, plenty of brightness and longevity. Their spiral "Tornado" bulbs are particularly good and set a benchmark.

But then a couple of years ago, just as the world was changing to compact fluorescents, Philips stopped all further development of those totally focussing its research efforts into LED light bulbs. They knew the future.

In recent years Philips have released high quality LED light bulbs that set high standards with very good colour, noticeably brighter than other led products available and with a life expectancy said to be in the 10 year range. They fall into 2 basic types.

The first are replacement units for the small halogen 25 and 50 watt MR16 miniature spotlights. The old halogen bulbs look great but they use a lot of electricity and are notorious for blowing easily and don't last long.

Philips LED miniature spotlights are designed to fit into existing MR16 fittings. They come in several different power outputs from 4 to 10 watts and give excellent light quality both in terms of colour and brightness. They also come in 12 volt and 220 volt versions and use the same small transformers that the old halogen mini spots did. Some are dimmable. Unlike the dreary LEDs we have been able to get up until now these really do match the performance of their halogen predecessors.

The second is a "screw in" type of light that fits the same fittings as the old standard A19 incandescent and compact fluorescent bulbs. The most technically advanced light in general production is the Philips L-Prize light so named because it won the L-Prize from the US Department of Energy. It replaces any standard 220/240 volt light bulb with a standard E27 screw fitting. It is LED, uses 10 watts of power while producing as much light as a previous 60 watt bulb and, like an incandescent bulb is fully dimmable. It is said to last 22 years and has no mercury in it.

A Comparison of Light Bulb Efficiency

Here is a comparison between different types of light bulbs:

* Based on usage of 6 hours per day.

As you can see the latest generation of LED lights use only a little more than half of the power per lumen when compared to compact fluorescent bulbs and less than a sixth of the power needed to illuminate the old incandescent lights.

This is only part of the story but is important because, by having bulbs available that replace existing standard light bulbs, LED lighting becomes accessible to the majority of existing houses.

If you go and try and buy a fluorescent strip light these days for your garage or office you may be surprised to find they won't have many in stock. Suddenly the market is offering 14 watt LED strip lights to replace the old 36 watt fluoro lights. They look good too, very compact and light in weight, good colour choice and not too expensive.

LED lights are leading a lighting revolution

You might also note that LEDs are starting to be used for street lights and even flood lights.

We are seeing a revolution in lighting technology and this is only the beginning, LED lighting offers far more potential for creative lighting ideas than the old incandescent lights.

Good quality LEDs are expensive with the miniature spotlights costing almost Rp200,000 ($20) each. But with considerably reduced electricity costs and life times of up to 10 years this high cost can be justified. We can expect prices to fall considerably as worldwide sales climb.

Finally a word of caution. In some parts of the world the electricity supply is notoriously unreliable with blackouts very common but of more concern spikes and surges that regularly destroy light bulbs. It is a good idea to put voltage regulators on your lighting circuits. Look for a good regulator that incorporates surge protection.