Green light bulbs: not such a bright idea

Some states are planning to ban incandescent light bulbs. But how bright will the future be under their gloomy, ‘energy efficient’ replacements?

Rob Johnston

Topics Science & Tech

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If Angela Merkel invites you to her place for a drink, don’t drop an earring. The German chancellor has replaced her light bulbs with the low-energy alternatives. At the European Union summit in March last year she joked, ‘Most of the light bulbs in my flat are energy-saving bulbs. They’re not yet quite bright enough. When I’m looking for something I’ve dropped on the carpet, I have a bit of a problem.’

‘Low-energy’ bulbs are all the rage, with environmentalists and politicians urging us to go out and buy dozens of the things. The UK and Australian governments have announced bans on the sale of traditional incandescent bulbs in the next few years. ‘Low-energy’ light bulbs are compact fluorescent lights (CFLs), in other words, smaller version of the tubes that grace many a workplace. They emit light as superheated mercury bombards a thick layer of white chemical phosphors on the inside of the glass. CFLs can only really be compared to ‘soft tone’ incandescent lights – there is no direct equivalent of clear bulbs in which you can see the tungsten filament burning intensely.

There are many claimed advantages of CFLs but before submitting to pressure from people like spiked’s very own militant environmentalist, Ethan Greenhart, pause for a second to consider the reality behind these mythical benefits – or risk being left to rage against the dying of the light.

They will save you money

If you have simple needs and unexacting standards, do plenty of research and don’t think of your time in terms of billable hours, then you might save a few pounds a year. Theoretically, CFLs use up to 75 per cent less electricity than the ‘light equivalent’ incandescent bulb. The UK’s Energy Saving Trust claims that just one CFL could save up to £7 a year. Given that CFLs are said to last up to 10 times longer than incandescent bulbs, this saving could rise to £60 over the life of the lower-energy bulb (1).

A CFL that uses 13-18 watts is supposed to produce the same amount of light as a 60-watt incandescent. However, almost no one believes the ‘light equivalents’ on the packaging of CFLs; many websites exist to compare the relative merits of the many brands, manufacturers and styles (2). In practice, to replace a 60-watt incandescent you need a 20-watt CFL for approximately the same lighting level, and for maximum life expectancy you should keep your CFL on for at least 15 minutes each time. Used in the correct manner, the direct energy saving may be much less than claimed – more like 25-30 per cent than 75 per cent.

A number of other factors can also drastically shorten the life of your CFL bulb and reduce any cost advantage: turning on and off too frequently; using it upside down (ie, socket ‘up’, light ‘down’ – in this position the heat from the light rises and overheats the electronics); fitting it in a recessed or enclosed position (overheating again); fitting it somewhere cold; putting it in an incompatible dimmer system (designed for incandescents), electronic timer, motion detector or light detector; or placing it anywhere that vibrates (eg, near a garage door or in a ceiling fan) (3). Special CFLs are available for some of these situations but they are significantly more expensive.

‘Green’ light bulbs save energy and reduce carbon emissions

In Britain, domestic consumption is only 30 per cent of total energy use (versus 34 per cent for transport and 22 per cent for industry); lighting and appliances together account for only nine per cent of that domestic usage – in other words, less than 2.7 per cent of total energy consumption. Over 80 per cent of domestic use is for heating and hot water (4). Of all the energy targets, lighting is the least significant.

Surprisingly, incandescent bulbs in the home contribute a noticeable amount to ambient warmth. About 85-90 per cent of the bulb’s energy is converted into heat, so the 30-40 to be found in an average four-bedroom house (totalling, say 3,000 watts) could produce as much warmth as a three-bar electric heater. Wholesale replacement of all those bulbs with CFLs will cause a drop in temperature. If the central heating is turned up there will be additional (mostly gas) energy use. Since 20 per cent of our electricity comes from very-low carbon nuclear power, the switch of fuel sources is not carbon-neutral.

In hotter countries, with air conditioning, the ‘waste heat’ of light bulbs is a greater problem than in the UK, where ‘waste heat’ is something of an oxymoron. CFLs also require considerably more energy to manufacture, but since all that takes place in the Far East, it is not so obvious to greens.

The light from CFLs is just as good as incandescents

Whether the illumination from a CFL is good or not is an aesthetic judgement – but the light quality is certainly different. Light from CFLs may appear gloomy, flat and yellow – or soft, even and warm depending on your preference. Just don’t expect them to be the same as your existing bulbs.

When the US magazine Popular Mechanics compared a range of CFLs with a standard 75-watt soft bulb in 2007 and said the incandescent came off worst, it was deluged with complaints from readers who had tried CFLs and found them wanting on every point from light quality to reliability (6).

Other problems with CFLs include: flickering; being slow to come on and warm up to full light level; light levels fading as the bulbs age; radio-frequency interference with electronic equipment and broadband signal and remote controls.

One good thing to come out of low-energy CFL bulbs is that lighting manufacturers have been stimulated to re-engineer the conventional incandescent bulb. GE – the largest US supplier – has announced that a new, much more energy-efficient incandescent design will be available by 2010 (7). Although supermarkets are phasing out 150W and 200W incandescent bulbs, they can still be obtained on the web. Buy now while stocks last.

CFLs are toxic

Some sceptical campaigners claim we should stick to normal light bulbs and shun CFLs because CFLs are dangerous. Apparently they’re toxic, might give you a headache, and they’re a pain to dispose of. So, should we refuse to switch to the new, supposedly ethical light bulb on the basis that they’re bad for us?

In truth, CFL bulbs contain only 5mg of mercury (about the size of a pin head) compared with 500mg in an old thermometer. Yet the instructions for how to clean up a broken one do make them sound as environmentally friendly as an oil spill: open the windows and leave the room for 15 minutes; wear rubber gloves; don’t vacuum a hard surface (it will spread the fumes); pick the pieces up with duct tape; wipe everything with wet towels; double-bag the debris; and then take to a specialist recycling centre (5).

CFLs also emit a tiny amount of ultraviolet light, which may be dangerous for people with medical conditions that make them highly sensitive to UV, but it is not a problem for the vast majority of the population.

In short, CFLs are perfectly safe. We should question their widespread introduction, not on dodgy safety grounds, but on the basis that they are not very good at providing light and are being promoted in order to make us all myopically obsessed with our daily emissions. The only headache these bulbs are likely to give us – apart from one induced by eyestrain while reading under their dim light – is to make us worry unnecessarily about the minutiae of our daily lives.

Rob Johnston is a freelance writer on the environment, health and science.

Previously on spiked

Rob Johnston debunked ten myths about nuclear power and said that the answer to our energy problems is not blowing in the wind. Mick Hume was semi-incandescent over Ken’s lightbulb ‘amnesty’. Josie Appleton urged London to keep the lights on. Or read more at spiked issue Energy.

(1) See A bright idea has got even better: Energy saving lightbulbs on the Energy Saving Trust website

(2) What Compact Fluorescents To Use Where, and Where Compact Fluorescents Are Not Recommended, Popular Mechanics, May 2007

(3) See GE Compact fluorescent lights FAQs, and
Lights of America, Instruction sheet, 20W Mini Twister Sunlight CFL

(4) See Energy Consumption in the UK on the Department for Business, Enterprise and Regulatory Reform website

(5) FAQs: Information on Compact Fluorescent Light Bulbs (CFLs) and Mercury, US Environmental Protection Agency, August 2007

(6) Where Compact Fluorescents Are Not Recommended, Popular Mechanics, May 2007

(7) General Electric Announces Advancement in Incandescent Technology; New High-Efficiency Lamps Targeted for Market by 2010, General Electric press release, 23 February 2007

To enquire about republishing spiked’s content, a right to reply or to request a correction, please contact the managing editor, Viv Regan.

Topics Science & Tech


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