Colin Sherwood says that inefficient light bulbs should be banned to help save the world (NCE letters last week).
Most offices, shops and public buildings that need lighting round the clock already use efficient bulbs on cost grounds. So assuming that increasing the atmospheric carbon dioxide content really does warm up the world, let's consider how much energy such a ban might really save.
In my house the lights are only switched on when it's dark. For at least nine months of the year, when it's dark it's usually cold, so I need heat as well as light. The 'inefficiency' of the light bulbs produces heat.
My central heating has a thermostat and therefore only produces the heat necessary to warm the house to the temperature I need.
So apart from the outside light, which comes on for a few seconds when someone approaches the house in the dark, the 'wasted' energy consumption of my dimmable, 'warm' wavelength, tungsten light bulbs is offset 100% by a consequent reduction in the oil consumption in my boiler for nine months of the year.
So I wonder just how much energy would be saved by using efficient bulbs during the other three months of the year when there are up to 18 hours of daylight.
Neil Besley (M), neilbesley@tiscali. co. uk