Final Report Lot 9: Public street lighting - Amper

Where:
• L [Cd/m2] is minimum maintained average road surface luminance;
• UO is minimum overall uniformity (of road surface luminance, illuminance on a road area
or hemispherical illuminance);
• Ul is minimum longitudinal uniformity (of road surface luminance);
• TI is maximum threshold increment: measure of loss of visibility caused by the disability
glare of the luminaires of a road lighting installation
• E [lx] is minimum maintained average illuminance (on a road area);
• Emin is minimum illuminance (on a road area).
Please note that there also exist the following classes that are less frequently used:
• The ES classes are intended as additional classes for pedestrian areas for the purposes of
reducing crime and suppressing feelings of insecurity.
• The EV classes in Table 6 are intended as additional classes in situations where vertical
surfaces need to be seen, e.g. interchange areas, roundabouts etc.
• The MEW series corresponds to the ME series but also includes UO specifications for wet
road conditions.
• Class A can be used complementary to class S and uses 'hemispherical illuminance' as unit.
From this summary of performance requirements can be concluded that:
1. there is a large difference between minimum illuminance (Emin) and minimum maintained
illuminance (E) for category ‘S’ street lighting;
2. there is a large spread within minimum maintained luminance (L) for category ‘F’ and ‘M’,
while the other parameters e.g. UO, Ul and TI are rather constant.
3. the primary functional unit of street lighting can be considered as luminance L (cd/m2) for
categories ’F’ and ‘M’, and illuminance E (lx) for category S’.
For all street lighting luminaires we assume they are designed to meet these performance
requirements, all options resulting in inferior performance are not considered.
1.1.3 Functional unit for street lighting
Knowing the functional product segmentation used in this study for street lighting and the
related performance requirements, we now further explain what is called the “functional unit”
of street lighting. In standard ISO 14040 on life cycle assessment (LCA) the functional unit is
defined as “the quantified performance of a product system for use as a reference unit in life
cycle assessment study”. The primary purpose of the functional unit in this study is to provide
a calculation reference to which environmental impact such as energy use, costs, etcetera can be
related and to allow for comparisons between functionally equal street lighting luminaires with
and without options for improvement. Reducing the functional unit to light output alone would
reduce the perspective mainly to parts (lamp and ballast) which can not be individually assessed
for street lighting alone.
The functional unit (FU) for street lighting in this study can be defined as:
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