Guidebook for Energy Efficiency in Municipalities

not clearly identifiable, try switching the power off and then on; the lamps may ‘strike’
at different times so the number of lamps will be more obvious.
If the floor area is difficult to measure because of obstructions, the ceiling tiles could be
counted. Each rectangular tile has an area of 0.74 m² and each square tile 0.37 m².
Prospecting for savings in office lighting
Begin searching for lighting energy savings by checking for:
Old, dirty fluorescent lamps and fittings: cleaning the fitting will help, and using
new, efficient lamps will allow getting the same amount of light from fewer lamps.
Fluorescent lamps dim as they age, so make sure the initial illuminance is sufficiently
higher than the maintenance illuminance, although the extra quantity required can be
minimised by using modern ‘through-life’ tri-phosphor lamps, which lose less than
10% of their initial light output over their rated life.
Lighting levels significantly above those required: this is usually because the
lighting has been designed assuming the space will be used for office work when it is
actually a walkway or staff room.
Incandescent downlights: each 100W incandescent downlight uses more electricity
than a 2 x 36 W fluorescent fitting, although it delivers about 80% less light. Also, the
downlight housing causes the lamp to overheat, shortening the already short lamp life
and adding further to maintenance costs. Compact fluorescent downlights will reduce
the power required by 70% and are available from €30 (plus installation). In a typical
office, each incandescent down-light replaced will save €5 to €15 in electricity costs.
Street lighting
Electricity distribution companies normally and, to a lesser extent, state departments that
administer arterial roads provide street lighting (equipment, maintenance, and energy) on
behalf of municipality. Of all municipal services, street lighting is the one that uses the
most energy. It is also an expensive activity. Good street lighting has an important role to
play in the community. It contributes to people’s quality of life by improving pedestrian
and traffic safety, as well as making people feel safer; it also improves the appearance of
the local environment.
A decade ago, the electricity industry consisted mainly of government monopolies, whose
main concern was the integrity of the electricity supply system. Street lighting was a small
additional task that accompanied the poles and wires asset, so it was not a high priority
and the energy efficiency of the service was a small concern. During the 1990s, much of
the electricity supply industry was divided into smaller parts, as generators separated
from distributors and energy retailers. For distributors street lighting is a bigger issue than
it was to vertically integrated utilities. Street lighting accounts for about 20% of the GHG
emissions attributable to a distribution company, so there is as well an environmental
incentive to improve its energy efficiency.
Opportunities for savings
An Australian investigation of street lighting from 1999 found that present street lighting
systems are inefficient, in that the quality of illumination of both minor and major roads is
much lower than can be achieved, and the energy efficiency is low. Apart from that, there
is a basic mismatch between the light colour produced by many streetlights and the light
colour that the human eye can use under typical street lighting conditions.
The study also found that the quality of street lighting could be significantly improved, and
the energy consumption at least halved, by a combination of: