The Ban The Bulb energy efficiency campaign is one of Dr Matt Prescott's environmental projects  | Contact BTB  
     Energy Saving Day (E-Day) | Oxford Earth Summit | Earth Summit Info | Environmental Rating Agency | "Heat" | 100 Years
                   Please contact Matt if you would like to support Ban The Bulb or next year's Energy Saving Day (E-Day) 
              A campaign to save money and help the environment by using energy efficient light bulbs

Thursday, August 02, 2007

The Guardian : Light bulb review
The Guardian has published a light bulb review I wrote for them which assessed the performance of a wide range of energy-saving light bulbs and rated them (out of 10) according to a key set of criteria including warm-up time, light quality, looks (size), lifetime and cost.

In general, I was pleasantly surprised by the recent improvements in the performance of energy saving light bulbs, otherwise known as compact fluorescent lamps or CFLs.

I also realised that the traditional-style (globe-shaped) designs of CFL produced a much more even and pleasing light, for a room, than the more iconic stick-shaped bulbs.

Some of the lamps were significantly better than the energy saving bulbs I had used before and I ended up recommending the 60 Watt equivalents from Philips (12 Watt, Softone, 8 year), Tesco (11 Watt, Energy Saver, Bayonet cap) and GE (11 Watt, Energy Saving Elegance) as the best all round performers (please see the review below).

The Philips design shown in this picture costs £3.99 per bulb and scored 10 out of 10 in all of the categories tested. It also claimed to last for 8000 hours.

The Tesco-branded bulb scored 8 or 9 out of 10 in all of the categories tested, claimed to last 6000 hours and cost only 81p.

The 100 Watt equivalents from Philips (20 Watt, Softone, 8 years) and GE (20 Watt, Energy Saving Elegance, 6 years) were also very good - although the Philips design was much more compact than the very bulky design from GE.

My thanks to Leo Hickman, Lucy Clouting and Bibi van der Zee for their assistance with the collection of the different light bulbs and the production of this article.

Bright lights

Still not convinced by the performance of eco light blubs? Matt Prescott founder of the Ban the Bulb campaign, puts the latest models to the test

The Guardian Thursday August 2 2007

Blame the 1970s. One of the problems holding back the uptake of energy-saving light bulbs has been that many people have still not forgotten the poor-quality versions they used then. But today, with lighting now using approximately 10% of the UK's electricity supplies, energy prices rocketing upwards, and a generally increased concern about the effects of climate change, many people say they are now prepared to give energy-efficient bulbs a second chance - provided that their performance has improved. So I put some compact fluorescent lamps (CFLs) to the test.

Although not perfect, the good news is that energy-saving bulbs have improved considerably, even over the past couple of years. They might not work properly with dimmers yet, but they are generally smaller, brighter and softer on the eye than they used to be. Because they work by making a phosphorous coating glow rather than by heating a filament, energy-saving light bulbs use 60% less electricity to make the same amount of light as an equivalent incandescent. This saves about £9 worth of electricity per bulb per year; or put another way, they last 6-15 times longer than the 1,000 hours of a traditional bulb and offer the UK a quick and simple way of cutting CO² emissions by 2-3m tonnes each year.

Despite these advantages, energy-saving bulbs are a lot more variable in their performance than we have come to expect from incandescents, and each make and retailer offers quite a different product. For example, it is possible to buy traditional globe-, spiral- and stick-shaped bulbs of varying size, cheap and cheerful CFLs from China, or relatively sophisticated CFLs from the major western brands, which incorporate many of the latest patents. For this review, I have stuck to a basic range of 100W- and 60W-equivalent CFLs.

My personal assessments are based on how well each light bulb worked in the same room, straight out of the box, and how happy I would have been to continue using each bulb in my own home. I have not been able to verify the life-expectancy claims for each one, as this is said to range from 6,000 to 15,000 hours (you can only watch a light bulb for so long), but I have mentioned the manufacturers' claims.

In most cases, the information available on the packaging was close to useless and took plenty of very determined reading to yield anything useful. None of the labels explained, in plain English, the amount of mercury in the bulb, how to dispose of it safely once used, its financial, carbon and energy savings, or the spectrum of light produced. Given that these are the first things people always ask me when seeking advice about what bulb to use, it's a shame this isn't standardised on all packaging.

The presence of mercury is something I am frequently asked about. A small amount is still needed in order to make all compact fluorescent lamps work, although the amount has steadily declined and is now about 50% less than used to be the norm even a couple of years ago, at approximately 4 milligrammes per bulb. The fact that it is still used is regrettable yet unavoidable at present, but the average quantity is three times less than the mercury released into the atmosphere by burning the extra coal need to power equivalent incandescent bulbs. As the mercury is contained within a sealed glass container it should be a relatively straightforward matter to recycle it safely. The EU's restriction of hazardous substances directive came into effect on July 1 2006 and provides a framework for how such recycling could be done, but is not yet law. To date, Ikea is the only company I know of that recycles all the CFLs returned to it and I hope it will not be long before all retailers follow suit in this important area.

And the results are ...

Following my test, I found that I preferred the performance of the traditional-style CFLs. They all produced a high level and quality of light within 1-3 seconds and produced an even light quality in all directions. The light intensities were good in all cases, and they all illuminated my test room more effectively than the stick bulbs, which cast light spots and shaded areas on the walls. The traditional-style designs from Philips offered the best performance. They warmed up to a bright light almost instantaneously and provided a very good even light around the entire room. The 100W-equivalent Philips bulb was more than capable of lighting a large room on its own. The traditonal-style bulb from Tesco also performed well against all of the test criteria and was very cheap at only 81p even though the life expectancy was relatively short at 6,000 hours.

· Dr Matt Prescott is director of the Ban the Bulb campaign (

Labels: , , , ,