Incandescent light bulbs (the classic filament bulbs) have changed very little since their invention in 1879. Around 95% of the energy they use is wasted as heat with only 5% going towards lighting our homes.

The average incandescent bulb lasts just five months to a year. Modern low-energy Compact Fluorescent Light bulbs (CFLs), on the other hand, require only 20% of the energy incandescents need to produce the same amount of light and can last up to 12 times as long.

For example, a typical 60W incandescent bulb will be replaced by an 11W Compact Fluorescent. The CFL will be more expensive to buy, but you will need to replace it eight times less often and it will use less electricity, which often makes it the biggest electricity saver in your house.

Fluorescent tubes are even more efficient than compact fluorescent lamps, and last even longer. One can easily calculate the savings done by changing old incandescent bulbs with compact fluorescent ones. In fact, over a period of a year one would be saving around €200 and reducing CO2 emissions by 620Kg. (assuming 8 light bulbs are changed, each of which are switched on for an average of 5 hours per day)

Like appliances, light bulbs are graded A-G (A being the best) according to their efficiency - so it makes sense to buy 'A' to maximise the savings you'll make. Compact fluorescent light bulbs are available in many different sizes and shapes to fit in almost any fixture—from three-way lamps to dimmer switches—for both indoor and outdoor use. Compact fluorescent light bulbs also come in a variety of colour temperatures, which helps determine the colour and brightness of the light each bulb provides.

Before you reach for the light switch you should consider other options that will save you money and help reduce emissions. One obvious thing to do is to open the curtains and blinds - you can't beat natural light, and it's free. Nothing can really match that specific yellow illumination of the sun. The sky's changeable character of light is very appealing and it's great to know what is going on in the atmosphere above you. It is also suggested that one clean the windows - you'd be amazed how much more light a sparkling pane admits.

Turn off the lights in any room you’re not using, or consider installing timers, photo cells, or occupancy sensors to reduce the amount of time your lights are on.

Energy-saving bulbs contain a small amount of mercury, which is highly toxic. Please dispose of them correctly.