Jane Powerson lighting up your life
There is no more potent (or calculable) symbol of saving energy than the light bulb. If a million Irish people decided to forgo their customary usage of a 100-watt bulb for just an hour a day, for example - say, by turning on the hall light an hour later - we'd be saving 100 megawatts of electricity. That's the entire capacity of Lough Ree, the troubled peat-burning power station in Co Longford.
Or if that incandescent 100-watt light bulb were replaced with a 25-watt compact fluorescent lamp (CFL), which generates the same amount of light, we'd be cutting the fixture's electricity consumption by three-quarters. Incandescent bulbs, which create light by heating tungsten filaments, are massively inefficient, as most of the energy is released as heat rather than as light.
A CFL, on the other hand, is a much cooler and, therefore, more efficient item. An electrical current passes through gas within the coiled or folded tube and produces ultraviolet light; when the UV rays hit the phosphor coating on the inside of the tube, visible and useful light is emitted.
For those of us who are accustomed to the warm glow of tungsten, the light can be unsettlingly cold. But CFL technology is progressing, and there are now bulbs with a colour temperature similar to that of the traditional light bulb. Look for "warm white" or "soft white", or a kelvin rating of 2,700. The higher the kelvin, the bluer and cooler the colour. Bulbs with a colour temperature of 5,000k to 6,500k mimic daylight.
Until recently CFLs were not compatible with dimmer switches, but now the energy-saving lamp manufacturer Megaman produces 11 watt CFL bulbs (approximately equivalent to a 60-watt regular bulb) that are capable of being dimmed, both from a rotary switch and a normal light switch (from Lamps & Lighting, Terenure Road East, D6; 01-4910185; www.lightdesign.ie). CFLs are now also available as candle bulbs for decorative fittings.
Compact fluorescent light bulbs are considerably more expensive than their incandescent relatives. But because their lifespan is six to 15 times longer, and because they burn a quarter or even less of the amount of electricity, the savings can be considerable: €100 or more during the lifetime of the bulb (see for yourself with the ESB's "energy-saving calculator" at www.esb.ie/main/ energy_home/appliance_calculator.jsp).
All CFLs contain a small quantity of mercury (about four milligrams), which means they should not be disposed of in the household rubbish. You can bring a used bulb back to the shop when you buy a new one (thanks to the WEEE directive), or you can dispose of it at one of the larger local-authority recycling facilities - but you'll pay the standard charge for a carload of waste, so make sure you bring lots of other detritus.