HID and LPS lamps produce the most light per watt of any light source. They create up to one-third less heat and last as much as 24 times longer then incandescent lights. Most parking lots and shopping centers use HID lamps, called High Pressure Sodium, since they are especially useful for outdoor security lighting. Use only the amount of light you need. Compact fluorescent lights and 3-way incandescent bulbs let you choose.
Watts measure the amount of energy going into a bulb.
Lumens measure the light output or brightness of a bulb. This information is printed on bulb packages. To determine efficiency, divide the lumens by the watts of electricity used. Fluorescent lighting delivers three to four times the light of incandescent bulbs of the same wattage and last up to 10 times longer. Inc. Web Pages by BayLogic , last rev.