|Energy efficient lights have come a long way in recent years. These days you get Compact Fluorescent Lamps (CFL) which use a fraction of the energy of the old lamps. A quality CFL will produce more lumens (intensity of light) than a cheap CFL for the same amount of energy consumed, so be careful when buying these lamps. Do not just compare prices and light putput when choosing a lamp.|
For an even more energy efficient solution, look at the LED lamps now available.
A lumen is a unit of standard measurement used to describe how much light is contained in a certain area, whereas a watt is the measure of power consumption. Looking at lumens is a simple and quick way of comparing lamps with similar power consumption but with differing lumens output.
For reference the following may be useful:
Tungsten-filament light bulbs produce about 15 lumens per watt.
Fluorescent bulbs produce about 56 lumens per watt.
A dinner candle produces about 12 lumens.