WE wouldn't need to worry so much about how we produce electricity, and whether it involves fossil fuels such as CO2 producing coal and gas, if we used less of it. It would also mean we could ignore the growing concern about the threat of blackouts as some of our ageing nuclear and coal fired power stations need time out for maintenance or are even closed down for good.

So until we have reliable ways of storing surplus renewable energy from sunny and windy days, or splash out on building tidal schemes around the country, we'll need to cut down on use, and save money at the same time. The answer is simple - it's the way we light the houses we live in.

It's well over a century since the gas mantle gave way to the electric light bulb, and the original incandescent bulbs should clearly have had their day by now, and long ago, but they persist in large numbers in all our houses. While they are cheap to buy less than three percent of the electrical energy produces light, with the rest being heat, and so the running costs are high.

These bulbs have now been banned in many countries, and have limited time left in the EU, and they have been replaced with compact fluorescent and LED bulbs, with the former producing at least five times as much light per watt, and the latter ten times.

Folk have generally been slow to buy LED bulbs because of the cost, though that has now reduced considerably. However an investment now will certainly save money in the longer term by reducing electricity bills as the following figures show.

Imagine a dark December evening, with folk home from school and work, and the main lights on downstairs. These will use about 15 gigawatts (that is 15 billion watts) out of a national total of around 55, so almost 30 per cent of the electricity production is used for lighting.

It's seems that if all the bulbs in the UK were LED ones the demand would fall by eight gigawatts, so saving 15 per cent of all electricity production, and additionally LED bulbs have much else to recommend them.

They light up instantly, last almost indefinitely, don't contain mercury and provide better quality light than most other bulbs. They cost more, but last about 20 years, and will pay for themselves in reduced electricity bills in two years so are a real investment.

It would also help if we fully turned off all equipment left on standby, such as computers, printers and televisions. Not wasting this electricity would reduce demand and bills by up to £100 every year.