Dumb eco-questions you were afraid to ask

New Scientist offers the definitive guide to everything you wanted to know about being green but were too embarrassed to ask

15th November 2008

If I switch the light on and off every time I enter and leave a room, does this use more energy than leaving it on all evening?

Switching the light on and off does saves energy, but there is a catch. Every time you flip the switch, the bulb takes a jolt of electricity, which shortens its life. Studies by the Electric Power Research Institute in Palo Alto, California, found that turning low-energy compact fluorescent bulbs on and off at frequent intervals can shorten their lifespan by as much as 75 per cent. The institute's director of energy…