amount of energy used from lighting varies from industry to industry, but typically,
lighting accounts for approximately 15% of the electrical load in industry. In offices,
the lighting may account for 50% of the electrical load. By having an understanding of the
lamps, ballasts, luminaires and control options available today as well as the techniques
used to develop efficient lighting, lighting can be produced that is energy efficient,
cost effective and yields a higher quality of light.
In recent years there have been many new developments in the lighting industry,
in both technological equipment and approaches to lighting design. The developments in
lamp technology have led to lamps yielding higher efficiency, improved colour rendering
and longer lives. Developments in electronic ballasts have produced ballasts that provide
discharge/ fluorescent lamps with flicker-free operation, longer life, faster run-up time
and cooler operation; in addition, some units provide smooth and silent dimming. There has
also been many developments in electronic controls for lighting, either daylight linked or
One result of these technological developments in the lighting industry has been the
improvement potential in lighting efficiency, thus a reduction in energy consumption and
costs. In many cases electricity costs for lighting have been reduced by 65% or more. The
simple payback for the costs of a lighting upgrade is typically between 1 and 3 years.
The additional result of the these developments in lighting has been the improvement in
the quality of light available, as introduced above. Through improving the quality of
light in an industry or commercial building, there is often an increased productivity, due
to better working conditions in the building or plant.
Improvements in lighting efficiency can be
obtained in seven distinct areas:
· Lamps - replacing inefficient lamps with the most efficient lamp
for the purpose, taking into account size, shape, colour and output of the lamp.
· Ballasts -
replacing standard choke ballasts with high frequency electronic ballasts.
· Luminaires - retrofitting standard luminaires with high-efficiency
(see Fig.2) specular reflectors or replacing standard luminaires with high-efficiency
(photo: Brian Cook)
· Automatic control systems - installation of (a) timer circuits that
switch lamps off during room vacancy times,
(b) photoelectric sensors that sense the amount of daylight in the room and either switch
lamps on or off or adjust the lamp brightness accordingly and
(c) occupancy sensors that switch lamps off when work stations are unoccupied.
· Localized switching -
installing localized switches near work stations to control local lighting.
· Lighting design - (a) designing lighting systems that maximize the
use of daylight, such as the PSALI system (permanent supplementary artificial lighting in
interiors) and (b) introducing local task lights (e.g. desks lights), allowing a reduction
in general overhead lighting.
· Maintenance schedule - setting up a maintenance schedule to clean
and replace lamps on a regular basis.
To read the full article exploring some of the recent developments in the
lighting industry, with the focus on methods of improving the lighting efficiency and the
quality of light in an industry or commercial building, please click here.