LED Home Lighting

The Main Energy Saving Light Bulb Options

It might or might not be news to you, but it is nevertheless a fact that for the past few years now most industrialized countries have been phasing out traditional incandescent light bulbs. In many places all incandescent bulbs of 60 watts and above are already unavailable as governments quietly enact legislation to enforce low energy lighting as part of a package of measures aimed at reducing global warming.

So then, whether or not you take global warming seriously, your government certainly does and consequently you will henceforth be required to light your own patch of darkness with low energy light bulbs. So what should you be looking for as you poke around the lighting shelves and find them now devoid of the old familiar light bulbs of yore?

For a start, low energy light bulbs currently come in two main forms: the fairly common CFL (Compact Fluorescent Lamp) which has been around a few years already; and the, as yet, less well known LED (Light Emitting Diode).

A Tale Of Two Technologies

In terms of purchase price and availability, CFLs are the cheaper option and having been around longer are more plentiful. Compared to incandescent bulbs, CFL are about 4 times cheaper to run and last longer, but given that they are also presently twice as expensive to buy, many wonder at the true savings to be had with CFLs.

At present LEDs cost at least twice as much again as CFLs and are still something of a novelty in lighting, though this is set to change and fast. Many DIY and general hardware stores only offer low power LED spot lights and color changing bulbs, which serve adequately for ambient and mood lighting, but are not realistic as replacements for much existing incandescent lighting.

However, high quality LED light bulbs are easily available from specialist lighting stockists and online, and these really are more than capable of replacing halogen lamps and conventional incandescent light bulbs. For example, the Cree EvoLux LED globe is available with preset dimmer settings to emulate general service lighting ranging from 40w through 60w and right upto 100w, which is plenty bright enough for most folk. Similarly, the Sharp Zenigata LED spotlight produces light virtually indistinguishable from a 50w halogen lamp. Consumers in the UK have the excellent EXERGI LED light bulb easily available, which genuinely does replace bright halogen spot lights.

The principal difference between an LED spotlight and say an equivalent halogen spot is energy consumption, or more precisely energy wastage through heat. Some 90% of the energy used to run a conventional light bulb disappears as heat; barely 10% goes towards the very job it is supposed to do, which is produce light. As you can see, the world’s electricity bill (of which 20% is accounted for by lighting) represents wasted money and resources, not to mention environmental harm, on a staggering scale.

This also brings us to a crucial point when considering the cost of electric lighting, which is that the cost is almost entirely made of the running cost i.e. the amount of electricity used to power the lights. The purchase price of the light bulb is for most practical purposes irrelevant.

But it’s not just spot lights and some GLS applications - there are now many LED replacements for fluorescent tubes and the ubiquitous G4 halogen capsule. Both these types of lighting are absolutely pervasive in work places, public buildings and to a lesser extent in quite a number of homes.

T5 and T8 fluorescent tubes are easily replaced by retrofit LED T5 & T8 equivalent tubes. Incidentally, the name denotes the tube diameter size and as is common with lighting specification is based on eights of an inch, so a T8 tube is 8/8 (or 1 inch) and a T5 is 5/8 of an inch in diameter. The principal difference though is light quality; T5 tubes are noticeably brighter and being slimmer you can pack more into the same area.

The obvious benefits of using LED “fluorescent” tubes are the significant cost savings thanks to vastly reduced power consumption, much longer lifespan, and lack of heat to compete with air conditioning systems. Another benefit is that LED tubes don’t produce that flickering effect and are unaffected when connected to energy saving systems that switch lights on and off automatically in response to the presence or absence of people (something that regular and compact (CFL) fluorescent tubes suffer badly from).

LED G4 capsule replacements are another way to tackle stealth halogen lighting applications; many people are not necessarily aware that G4 halogen capsules (very small bi-pin light bulbs) are commonly fitted in, for example, desk lights, slimline cabinet lights and other applications that require a very bright but also very compact light bulb (yet another example of where CFLs cannot deliver). And once again these ferociously hot and wasteful halogen lamps can be simply replaced with LED G4 retrofit versions that will pay back their investment costs many, many times over.

Getting back to the LED then, this technology presently reverses the heat to light ratio since over 90% of the input energy is converted to light with very little heat loss. The word “presently” however conceals the really astounding feature of LEDs which is that they constantly decrease in cost yet double in power roughly every 18 months. Since they are at heart simply electronic devices, their development parallels that of integrated circuits following what is known as Haitz’s Law (a variation of the famous Moore’s Law describing how computer chips get ever smaller yet cheaper and more powerful).

So we have in LED light bulbs a means to right now reduce energy consumption (and hence running costs and environmental damage) to 1/10th the current levels with the promise that this technology could improve 300 hundred fold within a decade. Put another way, where today you might replace a 60w light bulb with a 6w LED, in just 9 years time you could produce the same amount of light using an LED that consumes a mere 0.003w (3/1000th of a watt).

How To Assess Which LED Light Bulbs Are Right For You

So back to your purchasing decision then. CFLs are the easy option and you’ll certainly walk out of the store having spent less. But in terms of what they actually will save you, then as we have seen they simply don’t bear comparison with LEDs. In fact there are many other serious problems with CFLs relating to their poor aesthetic characteristics, disposal issues (they contain small but not insignificant amounts mercury), and production costs (they have a more complicated design).

On all these points, LEDs perform favourably, but the final nail in the coffin for CFLs is not so much that LEDs are already a better technology for producing high quality, low energy light, but Haitz’s Law. A quite literally dazzling future awaits LED lighting, where for CFLs their future is pretty much already behind them since leading lighting manufacturers such as Philips have already declared that they will discontinue research and development into CFL technology, diverting their resources instead towards LED lighting.

So should you be buying LED light bulbs (which are still fairly expensive) to replace existing lighting? Would it make sense to wait for prices to drop and power to increase? The fact is that if you run the maths it turns out that it’s considerably more cost effective to switch to LED at the earliest opportunity, even if you then upgrade again some years down the line to take advantage of subsequent improvements. To put it as simply as possible: any time you can purchase lighting hardware that significantly decreases the running costs you should do so.

An analogy with computers bears this out - if you kept waiting for the price to be “right” you would still not own a computer and would have pretty much missed out on the modern world as most of us now experience it. People expect to have to replace their computers every so often - not because they’re worn out, but simply to take advantage of the latest improvements.

So assuming you’re at least now interested in the possibility of LED lighting, what should you specifically look for to ensure you end up pleased with your purchase?

Checklist For Buying LED Lights

The thing to remember above all else is that at present cheap, low power LEDs are simply not capable of replacing most existing lighting. Budget LEDs are a false economy. Look for more expensive (yes, the prices will make your eyes water a bit) brand name products such as those mentioned above. These will deliver the both fantastic light quality and remarkable cost savings. I repeat, if you try to install LED lighting on the cheap you WILL be disappointed by the result.

Next comes the issue of assessing brightness. We are accustomed to rating light levels according to wattage i.e. 100w very bright, 40-60w comfortable, below 25w getting somewhat dim. This doesn’t work terribly well as a measure for LEDs. At the moment a reasonable estimate is that an LED will produce as the same level of light as a conventional bulb rated at 10 times its power, so for example a 5w LED should be quite sufficient to replace a typical 50w halogen spot lamp. But obviously, this is set to change as Haitz’ Law does its thing.

A better (or at least more direct) way to assess brightness is by luminosity, measured in lumens (for example, a standard 40w bulbs outputs 360 lumens). However, luminosity by itself is not enough to determine how bright a light source actually appears, since both beam angle and light “colour” are also key components to perceived brightness. Light color is graded using the Kelvin temperature scale where 2000k is referred to as “warm white” and values above 4000k are defined as “cool white”.

Up until recently, LEDs have tended to betray their intrinsically highly directional nature with a very narrow beam, and they have also until recently tended to be on the cool side of things, producing a bluish light. This produces a rather harsh effect with small pools of very bright light surrounded by dark spots. Modern high quality LED spotlights however have much wider beam angles (120 degrees fro example) which give a uniform light pool and their light color is also much warmer.

As a general rule then, the wider the beam angle and the warmer the color, the more an LED will emulate traditional incandescent light quality. Contemporary LED spot lights are especially well suited as low energy a stylish kitchen lighting alternative to halogen lamps.

To sum up, check the suitability of any particular LED light bulb for its intended application by checking the packaging (or if buying from a catalogue or online, the product description) for the following items:

• brand name, price and guarantee (plus an estimated lifespan - 50,000+ hours normally)
• luminosity (or equivalent brightness i.e. “same as 60w”)
• light colour temperature (stated as “cool” or “warm” or given in Kelvins - see above)
• beam angle

If there is scant description, then chances are you’re looking at a cheap low quality LED which is probably best avoided (an exception here being outdoor LED lights where low power is not usually a problem, though reliability is still an issue).