What is the most efficient lighting source available today?
The most efficient lighting sources available today are high intensity discharge (HID) and low pressure sodium (LPS) lamps. 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 than incandescence. Most parking lots and shopping centers use HID lamps, called High Pressure Sodium, since they are especially useful for outdoor security lighting. Despite their advantages, these lamps do have some special characteristics. Like fluorescent, they need special ballast and have a warm-up time of three to seven minutes, making them unsuitable for some situations.
