What’s happening to your light bulbs?

Since 2009 traditional “light bulbs” (more-correctly, lamps) have been systematically phased-out. This is a world-wide effort to greatly reduce the amount of electricity un-necessarily used by encouraging the development of ever-better low energy lighting. If you consider it is estimated there are some 700 million light bulbs in the UK, saving 90% of this extra electricity amounts to the output of several power stations.

For some 60 years most domestic light has been supplied by tungsten lamps (ordinary “light bulbs”), fluorescent tubes (often found in kitchens and garages) and – more recently – by halogen lamps (downlighters and security lights, for example). Commercial lighting tends to use more-efficient different types of lamp (sodium & metal halide for example) but these are generally larger and more expensive to buy.

These tungsten lamps have now mostly disappeared and are easily replaced with one of the following:

These were most commonly found in small downlights – and get extremely hot! They can now provide an almost indistinguishable replacement for old lamps. Generally they use about 80% of the electricity, and tend to be known as “Energy Saving” lamps.
As the name implies, these are miniature fluorescent tubes – usually coiled or folded in to a lamp-like size and shape. Although they are usually available in “warm white” (most like the old tungsten light) or “cool white” – and sometimes “daylight white” – they are seen by some as being unsightly and producing a slightly flickering – and harsh light. The earlier versions could take a little while to achieve full brightness, but this has been reduced markedly on newer lamps. They use about 25% of the electricity, should last much longer, and are known commonly as “Low Energy” lamps.
Although Light-Emitting Diodes (LEDs) have been around since the ‘70s (think of those little red lights on your hi fi) the development of white LEDs, and subsequently more-powerful LEDs has taken until very recently.
By design, LEDs are very directional – so they make very good spotlights. However recently developed are the equivalent of standard “bulbs” with an all-round light, and tubular replacements for fluorescent tubes. They come in warm, cool, or daylight white – although the colours vary with manufacturer (see chart below). They use around 12% of the electricity and should have a life well in excess of standard lamps (typically 30,000 hours is quoted).
A variation on the above. Due to the longevity of the actual LED, light fittings such as downlighters are made as sealed all-in-one units which are installed in the ceiling and forgeten about for several decades. There are no replace-able bulbs, and their efficiency, moisture-resistance and life are expected to be better than separate LED lamps above. Most manufacturers also give warranties of between 5 – 10 years.

What bulb should I buy?

Traditional bulbs were measured and sold in Watts (a measurement of the electrical energy they consumed). Thus one manufacturer’s 100-Watt bulb would use 100 Watts per hour, and had a brightness similar to other manufacturers’ 100-Watt bulbs … and we all knew where we were!

Now the same amount of light can be produced by much less energy (ie. a 20-Watt CFL can be as bright as a 100-Watt bulb) and we start to become confused! Fairly recently lamps have started to be labelled in a different way to try to iron-out this confusion: Brightness is now described in Lumens, and whiteness in “K” (thousands of degrees kelvin, colour temperature).

 The chart below shows the approximate equivalent power values for different types of light

Old Tungsten “bulb” Energy-Saving Halogen Low Energy CFL LED Lumens
100W 72W 22W 14W 1,400
60W 42W 15W 8W 800
40W 28W 11W 5W 450
25W 18W 8W 3W 300

The figures above are approximate, and for guidance only.

It is often commented that “these fluorescent lamps aren’t very bright” only to find that the lamp is only 11 Watts, and (as can be seen above) the equivalent of an old 40-Watt bulb – not surprisingly dim.

More commonly now, if you look at the packaging of a new lamp, it will tell you the old equivalent Wattage (i.e. 42W = 60Watts).

Other factors:

Colour Temperature

Old bulbs all roughly gave the same warm (yellow-ish) light.  CFLs and LEDs are available in several colours of “white”, described variously as Warm White, Pure White, Cool White, and Daylight.



The chart below shows the approximate colour temperature for each white (in degrees kelvin)

(Standard) Warm White Pure White Cool White Daylight
2500K – 3500K 4000K – 4500K 4000K – 5000K 6000K– 7000K

Daylight and cool white can be somewhat harsh in a living room, but perfect in an office or workshop.

Dimmable or not?

Like fluorescent tubes, standard CFLs and LEDs can not be dimmed.  If you want to use a dimmer you will need to buy specifically “Dimmable” versions of these lamps (which usually cost a little more).

Even then, LEDs are notoriously difficult to dim, and will usually require an LED-specific dimmer.  These can cost a little more than a standard dimmer.

Fittings (Caps)

There are numerous different fittings:  BC, ES, SES, SBC, R7, R7.5, G5.3, G4, G5, G8.5, G9, G11, 2D/2, 2D/4, TE, PL, DD, PLL, AR111, GX53, T4, T5, T8, and so-on. So – if in doubt, take advice.

There are many lighting solutions that you won’t find in your local DIY store, and Peak Electrics is happy to advise.

The future

There are many exciting ideas being developed.  We will have to wait – but be assured, Peak Electrics will stay abreast of available new technology.