Dimmable Energy Saving Lightbulbs

There are now many energy efficient lighting options available to replace old fashioned energy hungry incandescent light bulbs and halogen spotlights – primarily LED lighting, CFL (compact fluorescent lighting), and the latest CCFL (cold cathode fluorescent lighting).

Greenpeace dimmable CFL light garden

One major disadvantage of energy efficient lighting products has been their complete incompatability with dimmer switches (see our articles 240V LED Bulbs and Dimmer Switches, and LED Dimmer Circuit). Standard CFL bulbs work best and last longest if they are turned on for a minimum of 15 minutes each time they are used. Since modern dimmer switches work by turning the power on and off many times a second, they are completely unsuitable for use with CFL bulbs.

Dimmable Energy Saving Lightbulbs

CFL and CCFL bulbs are now coming onto the market which are not too expensive, have very long lifetimes, and can be used with dimmer switches. The key obstacle to dimmability was the ballast – the component in a CFL bulb which sends electric current through the gas filled tube causing it to emit light. Similarly, in the last few years, dimmable LED bulb technology has come on in leaps and bounds.

Disassembled CFL bulb showing the electronic ballast

The basic ballasts found in old CFL bulbs caused a certain amount of flickering which put a lot of people off CFL lighting. Modern electronic ballasts overcame this problem, and have since been improved to enable dimming (down to as little as 2% of maximum light level) and to allow CFL bulbs to be switched on at a low light level (rather than having to be turned on at maximum light level).

Some of the bulbs on the market at the moment can even be dimmed with a standard light switch. Flicking the light switch on and off puts the lightbulb into dimming mode; additional flicking of the switch on and off sets the desired light level. Alternatively these bulbs can be used with standard dimmer switches smoothly moving between 2% and 100% of maximum brightness.

Dimmable CFLs still offer the long lifetimes (up to 10x that of incandescents) and low power consumption (around one-quarter that of incandescents for equivalent light levels).

Buying Dimmable CFL, CCFL, and LED Bulbs in the UK

There are now (January 2013) many outlets selling dimmable CFLs in the UK – most of them online as these bulbs are still not mainstream. Bulbs are available in both bayonet (B22) and edison screw (E14 and E27) fittings, and now finally in GU10 * (240 VAC spotlight) fittings for replacement of existing energy-hungry halogen spotlights.
* Pictured below is a Megaman GU10 dimmable 11W CFL spotlight available for around £15 with a 10,000 hour average life. It is a direct replacement for a standard 50W halogen spotlight and will save 390kWh of electricity during its life – around £40-50 at today’s prices!

Megaman GU10 dimmable CFL spotlight bulb

The commonest power outputs available are 7, 9, and 11 Watts equivalent to 25, 40, and 60 Watt incandescents respectively, with ‘standard’ 11 Watt units (suitable for the commonest light fittings) available for around £10 with discounts for bulb purchases (typically 5 or more bulbs).Click here to read our Review of Megaman Energy Saving Lightbulbs which looks at the energy saving GU10 spotlights mentioned above, and also dimmable bayonet and edison screw fitting common bulbs and candles.

If you are looking for branded dimmable bulbs – it is Megaman which we have recommended since around 2010 with their CFLs. Now we also suggest you consider this range: Philips Master LED Bulbs (see image below) which are excellent quality dimmable LED bulbs.

Philips Master LED dimmable light bulbs

To save a lot of money if you want generic bulbs (typically one third the price of big name brands), the best bet is to have a look on eBay. Here are some tailored links which will help you find what you want quickly (since there are 100’s of thousands of energy saving bulb listings now):

B22 led dimmable – bayonet fitting to replace standard incandescent bulbs.
GU10 led dimmable – replacements for 35W and 50W mains powered spotlights.
E14 led dimmable – small edison screw for chandaliers – candle light bulbs.
Dimmable CFL – all dimmable CFL bulb options (note that in around 2011, dimmable LED bulb sales overtook dimmable CFL bulb sales, and there are now far more LED bulbs available than CFL/CCFL).