Is group re-lamping cost effective?

Group re-lamping greatly reduces spot re-lamping labour costs because all lamps are replaced before they reach the point in life where failures are accelerating. In addition, the cost of energy is by far the largest portion of maintaining a lighting system. If lamps are not group re-lamped, almost half of this energy will be wasted on lamps that are performing below their designed level. As an example, an average 400 watt metal halide lamp consumes $800 of energy over its rated life. About $320 of these dollars are wasted on lamps not providing optimum performance. With group re-lamping, a new lamp and the labour to install it is generally less than 5% of the total energy cost. Group re-lamping also saves downtime because it can be scheduled over a weekend or shutdown period.