Flashing Lights!
Q "I've installed energy saving light bulbs in all the rooms in my house. However, in some of them, after I've switched the light off it seems to flash before the light dims. This didn't happen with the old-fashioned bulbs I previously had fitted, so what's causing it, and is it safe, or have I got some defective bulbs?" - L Philips, London

A This is actually quite common, and is usually caused by the particular type of circuits you have in the house. Some houses have what's known as two-way switching circuits installed in some areas, usually halls and landings. On these circuits, the bulb can sometimes store a charge which, once switched off, bleeds away - producing the flickering effect you're describing.

The flickering is harmless, and should not happen every time you switch off the light. However, if the bulb is constantly flickering then you may need to have it replaced. And, if the same socket is also flickering with a standard non-energy saving bulb installed, you should have a qualified electrician check the socket and the circuit, as this may indicate a more serious fault in your electrical system around the house.

Deliver or Drive?
Q "In your last issue, the Childs family congratulated themselves on having their organic food delivered. But wouldn't they have been better off walking to the nearest supermarket instead? Even delivery vans use energy!"- Mr Abrahams, via email

A If possible, the best way you can get your shopping is to walk rather than use any kind of motor vehicle - and it's good for you too! However, this isn't always practical if you have difficulty getting about, or if you have a large family to feed. If it's a choice between driving and delivery, in general, in urban areas, a single van delivering goods will be more energy efficient than several cars each making their own journeys. And don't forget the humble milk float too - if you can get staple foods delivered by these marvellous electric vehicles, it can save a lot of energy!

Travel Plans
Q "I recently read a report claiming that, for a family of four, it was actually more energy efficient to drive than take the train. Is this true?" - A Mitchell, Brighton

A There are no absolute rules on this, as it depends partly on how many people are travelling and how far. However, flying, no matter how "green" the aircraft, isn't yet as energy efficient as road or rail, so you should rule that out as an option. Generally speaking, rail will be the most environmentally friendly option. However, for a family of four, car or coach may actually turn out to use less energy, but it depends largely on how new and efficient the vehicle is. A small, well maintained family car which is travelling a long distance with a full load of people may turn out as the most energy efficient method of transport.