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Does banning the traditional light bulb make environmental sense?August 2009

The much-maligned light bulb is being phased out in favour of compact fluorescents. But will the ban make environmental sense? Richard Forster weighs up the evidence.

In a recent debate in the House of Lords, Lord Harrison asked: "How many politicians did it take to change a light bulb policy?" This question was raised in Delta T in June 2007. Lord Hunt responded: "It takes one member of your Lordships' House to change a light bulb and 712 to debate the matter for endless hours."

The economic and environmental cases in favour of compact fluorescent lamps (CFLs) against domestic light bulbs have been made for many years and yet have failed to convince the buying public. The recent increases in electricity prices have strengthened the financial argument, but to little effect on consumer buying habits.

A political solution was to remove the choice and force domestic light bulbs off the shelves. This was not by legal abolition, but an informal agreement last year by the major UK retailers that sets out a staggered timetable starting with 150 W lamps and above.

Table 1: The European phase-out plan for GLS and halogen lamps

Confusingly the European lamp manufacturers reached a similar conclusion but their timetable lags behind that from the UK (Table 1). In addition the lamp makers promised to introduce new energy-saving lamps that would retain some of the performance features that CFLs could not match.

The UK voluntary phase-out schedule for major supermarkets, large retailers and DIY stores for general lighting service (GLS) lamps is as follows:

Table 2: Comparison of GLS lamps and new halogen lamps (*From OSRAM packaging)
  • January 2008: cease to replenish 150 W lamps and above
  • January 2009: cease to replenish 100 W lamps and above
  • January 2010: cease to replenish 60 W lamps and above
  • January 2011: Cease to replenish all remaining GLS lamps
  • 31 December 2011: cease selling all remaining GLS lamps along with 60 W candle and golf-ball lamps.

As a consequence tungsten halogen lamps are now appearing that emit almost the same light output as 40, 60 and 100 W light bulbs but which consume about 30 per cent less energy and last twice as long. This technology was first introduced commercially in the 1960s with the addition of halogen gases to reduce the evaporation of the tungsten filament.

As they retain the tungsten filament of the light bulb, halogen lamps offer the same good colour appearance and rendering. They are suitable for use with existing dimmers. Unfortunately these new domestic halogen lamps emit slightly less light. This is probably insignificant in normal circumstances, but it weakens public confidence and provides an excuse not to change if the performance of replacement lamps is not truly equivalent.

For the aged and visually disabled, the reduction in illumination is more important and may present difficulties. A good point is the adoption of three new ratings of 28, 42 and 70 W as the norm by the lamp makers. This would appear to be obvious replacements for 40, 60 and 100 W lamps.

Information on the new halogen lamps is sparse and the only indication of light output is on the packaging where it is a requirement. Has the ambitious time scale set by the UK allowed sufficient time for the European lamp industry to restructure its manufacturing capacity?

Research for this article revealed that during January 2009 the shelves of the local supermarkets were devoid of 100 W GLS lamps with large empty spaces where the 70 W halogen lamps should have been placed. This halogen substitution is easier to comprehend than for CFLs, where there are 7, 8, 9, 10, 11, 13, 15, 16, 18 and 20 W ratings to replace three GLS ratings. This is confusing, and compounded by the various shapes, colours and differing lamp lives.

While the halogen lamp is much closer to the GLS lamp (Table 2), the energy and cost saving are much less than can be achieved by changing to a compact fluorescent lamps (CFL). So the first choice should always be CFLs. Figure 1 indicates typical domestic costs based upon today's prices.

For technical reasons CFLs are only produced as the better fluorescent colour options. When shopping, we all choose clothes, furniture, and food are under fluorescent lighting - the normal environment that has replaced daylight. Switching on lighting is more an indication of occupation than a call for illumination.

Figure 1: Typical domestic lamp costs per thousand hours based upon 2009 prices

European legislation has placed restrictions on hazardous substances, including the amount of mercury in fluorescent tubes. Today's products contain less mercury than in the past. However, disposal becomes a problem with fluorescent lamps as domestic products. The WEEE Directive calls for separate collection of waste electrical and electronic products to ensure specific treatment and recycling.

For this purpose convenient facilities should be set up including public collection points where private households should be able to return their waste free of charge. The local refuse centres perform this role, but householders have expressed reluctance to make a special journey for the odd failed lamp and are therefore putting CFLs in with household rubbish. This means the mercury is going to landfill, which is not what the legislation intended. So what constitutes 'convenient' needs further consideration by all parties concerned.

The final twist is that the current halogen lamp is also due to be phased out in a second stage proposed by European lamp companies unless its efficacy can be improved and the wattage ratings reduced further. Without more development such as different gas fillings or infrared coatings, halogen lamps may therefore have only a short stay of execution. Clearly a case of 'watch this space'.

So far there are a lot of questions but few answers. It is worth recalling that the filament lamp went through about 50 years of development before reaching maturity. Although the perception is of more rapid progress today, we may have to wait until 2020 before CFLs reach their prime.


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