Consider discharge lighting in industrial applications

Capital cost for this is

£60+ for a discharge fitting. The energy saving available is up to 50% if discharge lighting is chosen correctly, but an increase in consumption of up to 20% is possible if chosen incorrectly.

When good colour rendering is not important (such as in certain industrial areas, warehouses etc), many forms of discharge lighting offer a practical energy saving alternative to fluorescent tubes. There are, however, limitations that must be borne in mind:

As the energy savings figures imply above, there is considerable variation in the efficiency of the various types of discharge lighting. Fluorescent tubes are more efficient than certain forms of discharge lighting (particularly some mercury discharge lights). It is essential to choose wisely, checking manufacturers figures for bulb efficacy (light output per watt).

Discharge lamps do not have the dimming capabilities of fluorescent tubes.

The colour rendering is worse with discharge lamps than with fluorescent lamps (colours look unnatural with discharge lighting). As a rule of thumb, the higher the energy efficiency of the discharge lamp, the worse the colour rendering.

Discharge lamps cannot be started with immediate full light output, rather they take a few minutes to warm up to full luminous flux. Thus they are not suited for applications with frequent switching.

The above limitations demonstrate that only certain areas are appropriate for discharge lighting. However, if a continuous source of light is required in an industrial area with minimal daylight, discharge lighting can provide a highly energy efficient lighting solution.