2) Lights powered by small Photovoltaic (PV) modules that convert sunlight directly into electricity. Consider PV-powered lights for areas that are not near an existing power supply line.
3) Outdoor lights with a photocell unit and motion sensor will turn on only at night or when someone is present.
4) Exterior lighting is one of the best places to use CFLs because of their long life. If you live in a cold climate buy a lamp with a cold weather ballast since standard CFLs may not work well below 40*F.
5) Consider high-intensity discharge (also called HID) or low pressure sodium lights.