They cost more, but save money over their life because of savings in energy and lamp costs. Install them in high-use fixtures for a quicker payback. For example, one 100 Watt incandescent bulb will burn for about 1,000 hours. To get the same amount of light you would need two 13 Watt CFLs, which would use a about 75 percent less energy and burn for about 10,000 hours. Use fixtures that direct light to the task Light fixtures help distribute light and control glare.
Some designs work better than others.
Efficient designs typically are more open and use highly reflective surfaces. Direct light to surfaces and tasks, not to the floor. Choose fixtures that are easy to clean and allow easy replacement of lamps. Use lamps that the fixtures are designed for. Keep rooms light and low A room's shape, size and color affect how much light you need to provide.