Lights Out For Incandescents

2005 October 30
by Chris Vernon

Light bulbPeak oil may be upon us, but I fear the primary challenge for the UK isn’t oil but rather electricity. With rapid decommission of the aging nuclear fleet and falling extraction rates of indigenous natural gas and coal, our three main sources of electricity (accounting for some 95% of our electricity supply) are all in decline.

For this reason, the country is planning an incredible increase in natural gas and coal imports – with apparently little concern for the effect on the balance of payments or the security of supply. Political debate is also approaching the need for a new nuclear build programme. However I am left thinking that although this shortage is arising from declining supply, the solution lies on the demand side.

This earlier article on Dynamic Demand shows a simple method which adjusts the profile of demand with respect to supply, allowing a far greater degree of intermittency to be tolerated without sacrificing utility. This in turn eases the deployment of renewables, usually criticised for their intermittency compared to traditional energy generation.

Light Bulbs
I have recently moved house and was amazed by the lighting arrangements in the new property. Incandescent bulbs throughout, with multiple spot lights in the kitchen and one other room, and not only that but each bulb had a lampshade hanging below it shadowing the room so that even with 100W bulbs the rooms were dim.

We’ve been using compact fluorescents for about 5 years now, but now I’m thinking enough is enough. Tesco et al need to stop selling 100W incandescent light bulbs for 18 pence each. In fact, the Tesco price isn’t the issue; I believe government should legislate against the manufacture, import and sale of incandescent bulbs. There is just no justification for incandescent bulbs and every reason for us to reduce our electricity consumption. The incandescent light bulb is as old as domestic electricity itself, its invention credited to Thomas Alva Edison in 1879, and remains little changed to this day. I think it’s time to bid farewell to this invention, celebrating the profound impact it has had on civilisation whilst at the same time recognising its inefficiency and therefore unsuitability for an energy scarce future.

At a personal level each 100W bulb used for an average of four hours a day will use 146kWh a year, costing £10.22 (at a typical 7 pence per kWh). Compare this to the 20W equivalent compact florescent which only uses 29.2kWh costing just £2.04 over the year, a saving of £8.18 per bulb. Say the average household has five bulbs with that kind of duty cycle and we’re looking at an annual saving of £40.88 on the electricity bill.

Some common misconceptions about modem compact fluorescents are covered here:

Do they flicker when you turn them on?
Yes, they do, but unlike early energy saver lamps a few years ago, the latest designs generally include electronic rapid start circuitry to make the lamp light in less than 1 second with virtually no flickering.
Don’t they give a rather harsh light?
Some older designs had quite a high “colour temperature” (see glossary) which may be perceived as “colder” but many energy saving lamps now use a “warm white” coating to make the light very similar to a normal incandescent bulb.
Do they take time to “warm up”?
The latest compact fluorescent lamps “warm up” very much faster than older designs, typically reaching 95% of their full light output in under a minute.
They are always too long and stick out above my lampshade!
Again, with the latest designs, this need not happen. Many compact fluorescents are now so small that they are virtually the same size, or even smaller, than ordinary bulbs. If the bulb is visible, you can choose from one of the designs that uses a decorative outer bulb to cover the fluorescent tubes.
Lightbulbs Direct

Compact fluorescents do cost more, typically a minimum of £3-5 compared with incandescents at 40 pence (I can only assume the 18 pence Tesco bulbs are a loss leader, similar to the £1.49 Ikea compact fluorescents, so won’t use those figures), however since compact fluorescents last 5 to 10 times longer than incandescent this unit cost differential is negligible.

At the national level, each of the 22 million homes saving 585kWh a year would save 12.9 Terawatt hours. For reference, a large nuclear power station generates approximately 8.8 Terawatt hours a year. So just the single, simple, modest action of replacing the incandescent light bulbs in domestic homes (which could be phased in over several years as incandescent bulbs need to be replaced) would reduce our electricity demand by one and a half nuclear power stations worth.

If government were to ban incandescents in a similar way as lead pipes and asbestos are already banned, then the average household would save around £40 a year and the nation would save the construction, operation and decommission of one and a half nuclear power stations (or equivalent gas/coal imports). Other benefits might include reduced number of household fires started by hot lamps or faulty wiring (less current being drawn through the lighting circuit), fewer people falling off chairs or electrocuting themselves changing bulbs (since the number of changes would be reduced by 80-90%), and less raw materials and landfill needed for construction and disposal of incandescents.

Any absolute ban like this would also remove incandescents from business and industry providing further energy and financial saving on top of those discussed for domestic users.

No comments yet

Leave a Reply

Note: You can use basic XHTML in your comments. Your email address will never be published.

Subscribe to this comment feed via RSS