ABSTRACT
Lamp efficiency, called luminous efficacy, is expressed in Lumens per Watt or lm/W. Compact fluorescent lamps, which are widely used in homes, are characterised with efficacies of around 55 lm/W. Fluorescent-triphosphor lamps, such as T5 (Figure 150), are high efficacy lamps, with up to 100 lm/W). LED lamps are based on light emitting diodes. Their efficacy varies, but it can be greater than 125 lm/W, with latest prototypes reaching 160 lm/W. This means that LED lamps are more efficient than the most efficient fluorescent lamps and far more efficient than the most efficient compact fluorescent lamps.
