Improving the efficiency of school lighting is one of the easiest and fastest ways to save energy. There are two types of bulbs available as replacements for traditional incandescent bulbs.

Compact fluorescent bulbs (CFLs) are by far the most popular alternative to incandescents because they're both efficient and relatively inexpensive. They are widely availabe and come in all shapes, sizes and wattages. However, the small amount of mercury (a potent neurotoxin) contained in CFL bulbs remains a problem for disposal and if breakage occurs.

For this and other reasons, the market for Light Emitting Diode bulbs (LEDs) is growing. Their light is the color of daylight (or any color you want), they use only 2-10 watts of electricity and last up to 60,000 hours (that’s about 41 years if you use the light four hours a day.) In addition, they generate almost no heat, go on instantly, and focus light right where you need it. They are expensive ($30 to $60 each) but the savings in energy and replacement costs are significant.

Resources:

The Environmental Defense Fund has a handy online bulb locator where you can specify the type of fixture you have, and the shape, brightness and color you want, and the program will find the perfect energy-efficient bulb for you.