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Values of the power density indicator (Dp) shall be always presented and used together with the annual energy consumption indicator (De) for assessment of the energy performance of a particular lighting system.

For illuminance based lighting classes (C and P) the maintained average horizontal illuminance (E) to be used for the power density (D_P) calculation shall be calculated according to EN 13201-3.

For luminance based lighting classes (M) the maintained average horizontal illuminance (£) to be used for the power density (Dp) calculation shall be the average of illuminance values calculated on the same grid of points which are used for the calculation of luminance in accordance with EN 13201-3.

For hemispherical illuminance based lighting classes (HS) the maintained average horizontal illuminance (E) to be used for the power density (Dp) calculation shall be the average of illuminance values calculated on the same grid of points which are used for the calculation of hemispherical illuminance in accordance with EN 13201-3.

Some lighting installations may be over lit in terms of significantly higher lighting levels than those required or specified. When such over lighting occurs, it should be determined if this is as a result of poor design or as an unavoidable consequence of other requirements. From an energy efficiency and environmental perspective corrective action should be taken to minimize any over lighting.From an energy efficiency and environmental perspective the calculated lighting level for any lighting installation should not exceed the required lighting level of the next higher lighting class (or not exceed the required lighting level by 50 % in case of the highest class) without considering other design solutions.

The system power (P) shall be calculated from the sum of the operational power of the light sources, control gear(s) and any other electrical device(s) (lighting point control unit(s), switch(es), photoelectric cell(s), etc.) which are directly associated with the lighting of the area to be lit and installed in order to operate or regulate the installation. The system power (P) should be calculated for the complete lighting installation or the representative section used during the lighting design according to the following formula:

%

Р = (2)

k-1

where

P is the total system power of the lighting installation or its representative section, in W;

Pk is the operational power of the 'k^th' lighting point (light source, gear, any other device like lighting

point control unit, switch or photoelectric cell and component, which are associated with the lighting point and necessary for its operation), in W;

Pod is the total operational power of any devices not considered in Pk but necessary for the operation of the road installation such as a remote switch or photoelectric cell, centralized luminous flux controller or centralized management system, etc. in W.

Where the system power is calculated for a representative area the total operational power P_ad should be proportioned according to the number of luminaires used to illuminate the area over the total number of luminaires supplied from the devices represented by P_Od.

nip is the number of lighting points associated with the lighting installation or the representative section whichever is used in the calculation.

If light sources (and other electrical devices) are operated on constant power, this power shall be used when the system power (P) is calculated.

If the lighting class changes during the night and/or seasons (for example reduction in lighting class during the night due to decreased traffic density, changes in the visual environment or other relevant parameters), the system power (P) corresponding to the required lighting class in that period should be calculated.

NOTE PDI can be a single number for full-time constant power operation and for 100 % dimming level in regulated systems, or it can represent different numbers for each considered state of operation. Annex A gives examples of calculation and Annex D gives an example of the presentation of results.

Where the luminous flux output of the light source is varied to compensate for changes in luminous flux output throughout lifetime of the light sources (for example the light sources use constant light output (CLO) drivers), the average system power associated with these variations should be used for the calculation of power density (D_P).

If the calculation for the main lighting class is based on a single calculation for a section of the road, i. e. for a typical arrangement and spacing, then the system power (P) calculation shall include the sum of the power of all luminaires and the electrical device(s) related to luminaires, lighting points and segments which are inside and on the edges of the calculation area relevant to this typical arrangement, in accordance with EN 13201-3. Annex A shows some typical examples. The number of luminaires and size of the area shall be relevant to each other.

If the calculation is performed for an irregular shaped area, the system power (P) calculation shall include the sum of the power of each luminaire and the electrical device(s) related to luminaires, lighting points and segments, which are needed to light the area.

The system power (P) should not include any power associated with devices which are not used to fulfil the lighting function, even if they are connected to the same network. Typical examples are illuminated advertisement and festive lighting.

The area used for calculation of the power density indicator (Dp) shall be identical to the area used in lighting design for lighting calculation of parameters according to EN 13201-2 and described in EN 13201-3.

If the carriageway of a road is not surrounded by other areas (for example another carriageway, footpath, cycle path or parking areas, etc., which have their own individual specified lighting requirements) and Edge Illuminance Ratio (E1R) is calculated in accordance with EN 13201-2, the surrounding areas used for calculating E1R are not included in the calculation of power density indicator.

5. Annual Energy Consumption Indicator (AEG)

The annual electricity consumption of a road lighting installation depends on:

• the period of time for which lighting is provided,

• the lighting class specified by the relevant lighting standard for each lighting period,

• the efficiency of the lighting installation, when providing the necessary lighting for each period,

• the way the lighting management system follows the change in visual needs of road users,

• the parasitic energy consumption of lighting devices during the period when the lighting is not needed.

For comparison and monitoring of the energy performance of a lighting installation, the energy consumption indicator shall take into account the annual accumulated energy use of road lighting illuminating the street or public area, however actual lighting needs may vary during the year because of the following reasons:

• seasonal variations of daylight / night time hours: this depends on the geographical location of the area,

• changing weather conditions which influence perceived visual performance (i.e. dry or wet road surface),

• changing traffic density on the street or public area during the night (i.e. different temporal pattern of usage such as increased usage at "rush hour”) or following the fluctuation in social activity (i.e. school terms, national holiday periods),

• changing functionality of the street or public area (i.e. roads are closed for a certain period or turned to pedestrian areas in festive seasons).

Annual energy consumption indicator (AECI) shall be calculated with the following formula: m

D_e- ^r (3)

/1

where

De is the annual energy consumption indicator for a road lighting installation, in Wh-nr²;

Pj is the operational power associated with the j^th period of operation, in W;

tj is the duration of j^th period of operation profile when the power P, is consumed, over a year, in h;

A is the size of the area lit by the same lighting arrangement, in m²;

^m is the number of periods with different operational power Pj- m shall also consider the period over which the quiescent power is consumed. This period would generally be the time when the lighting is not operational, i.e. daylight hours and any night time period when the lighting is not lit.

If the light output of a light source is intended to be constant, but the power consumption of this light source (or other electrical devices) varies in time (for example if constant light output (CLO) drivers are used), the average power consumption over the anticipated lifetime shall be included in the calculation. The calculation shall clearly indicate the lifetime assumptions used for calculation of the average consumption and how this value was evaluated.

Annual energy consumption indicator (D_K) shall be always presented and used together with the values of the power density indicator (Dp) for assessment of the energy performance of a particular lighting system

.Annex A

(informative)

Examples of calculation and typical values of energy performance indicators .

A.l Examples of operational profiles

A.1.1 General

Typical examples of daily operational profiles for road lighting are given below. Start time and end time of operation change throughout the year and depend on the geographical latitude and local conditions. It is advisable that the operation of artificial lighting is correlated with illuminance from daylight with respect to the illuminance required for a particular lighting class according to EN 13201-2. In the moment of sunset the illuminance level is considerably high but rapidly decreases. At sunrise the situation is reversed.

Examples of operational profiles in this annex illustrate the daily course of lighting level. Power level needed for the calculation of energy performance is associated with lighting levels depending on lamp type, lamp power and other factors.

NOTE 1 This annex does not deal with particular relation between lighting level and power level. '

For the calculation of AECI it is necessary to sum up daily operation hours for each of the lighting levels throughout a whole year.

NOTE 2 Parasitic power is not included in the operational profiles presented below.

A.l.2 Full power operation

The profile in Figure A.l is typical for lighting installations with simple switching devices like time switchers or photosensors. Luminaires operate constantly at full power throughout the night time each day.

у Юо

80

60 ■

40

2o

0 і —і 1 1 1 1 1 1 1 1 1 1— і

16 17 18 19 20 21 22 23 24/0 1 2 3 4 5 6 7

x

Key

x daily course of operation (h) у lighting level (%}

Figure A.l — Full power operational profile

A.1.3 Multi-power operation

The multi-power profile (e.g. bi-power profile shown in Figure A.2) consist of two or more time periods during the daily course when luminaires are operated at different power associated with different lighting levels provided. Each of the lighting levels should be derived from lighting class according to EN 13201-2.

У 100-J

80

60 —

40

20

0 h— і 1 1 1 1 1 1 1 1 1 1 1 і

16 17 18 19 20 21 22 23 24/0 1 2 3 4 5 6 7

x

Key

x daily course of operation [h]

у lighting level (%)

Figure A.2 — Bi-power operational profile

A.1.4 Operation with vehicle and presence detectors

If vehicle and/or presence detectors are used to control the lighting system, full power or multi-power operational profiles are truncated by time periods when no traffic is sensed by the associate detectors and luminaires operate at reduced levels. Figure A.3 shows an example of tri-power operational profile for lighting control with detectors where at least a minimum lighting level is kept throughout the night time. Peaks depicted in Figure A.3 depend on sensing and are not periodical. For calculation of AECI it is necessary to assume for annual probability parameter for each of the lighting levels.

x

Key

x daily course of operation (h) у lighting level (%)

Figure A.3 — Tri-power detector-driven operational profile

A.2 Example of calculation

Calculation of the energy performance indicators PDI (Clause 4) and AECI (Clause 5) is additionally explained by means of an example depicted in Figure A.4.

A generic road profile consists of two lane carriageway with sidewalks on both sides and grass strips separating them from carriageway.

Lighting poles are installed in the grass strip between the carriageway and the right sidewalk. Two luminaires are installed per pole: Luminaire Pr for illumination of the carriageway and the distant (left) sidewalk partially also illuminates the right sidewalk. An additional luminaire Pf is installed to support the illumination of the right sidewalk and is, therefore, oriented towards this sidewalk. System power of the luminaires Pr and Pf is the nominal power usually provided by luminaire manufacturer. If calculation of energy performance is performed for a typical field between two consecutive lighting poles according to EN 13201-3, system power Pr and Pf is included in calculation only once. If calculation of energy performance is performed on the entire road length or its section longer than a single field for photometric calculation, all luminaires associated with this road section are included.

Illuminated areas for the carriageway Ar, left sidewalk A_F,. and right sidewalk A_FR can be calculated from the corresponding widths of road profile and the considered length of the installation (length of the road, road section or spacing of luminaires). Illuminance of the carriageway Er, left sidewalk Efl and right sidewalk Err should be calculated in accordance with EN 13201-3. Areas of grass strips and strips for calculation of the edge illuminance ratio are excluded from the calculation of energy performance indicators.

For calculation of AECI it is necessary to take into account the lighting control profile applied to lighting system as combination of reduction coefficient and annual operation time for each of the operational regimes and probability of motion detection, if used. For example in case of the widely used bi-power operation (see A.1.3) the total annual operation time is divided to the time of full operation tf_Un and the time of reduced lighting level Led when the system power is lowered by the reduction coefficient k_red.

Figure A.4 — Situation and description of parameters for calculation of PDI and AECI as an
exampleW

above,

(A.1)

(A.2)

hen applied to the situation in Figure A.4, and respecting the assumptions mentioned Formulae (1) and (3) for the calculation of energy performance indicators become as follows:

D_P=

^£FL ’^FL + A ‘ A? + Ar ’^FR

£) _ ⁺) ' (^full ⁺^red ' A )

Al ⁺ A ⁺ Ar

where

Pr is the system power of the main luminaire in the lighting installation, in W;

Pt is the system power of the auxiliary luminaire for illumination of the right sidewalk, in W;

Ar is the area of the carriageway, in m²;

Afl is the area of the left sidewalk, in m²;

Afr is the area of the right sidewalk, in m²;

Er is the calculated maintained illuminance on the road, in lx;

Efl is the calculated maintained illuminance on the left sidewalk, in lx;

Efr is the calculated maintained illuminance on the right sidewalk, in lx;

tfuii is the annual operation time of the full level illumination, in h;

tred is the annual operation time of the reduced level illumination, in h;

kred is the reduction coefficient for the reduced level illumination.

In Formula (A.2), for both luminaires the same lighting control profile is applied.

A.3 Typical values of energy performance indicators

A.3.1 General

Values of energy performance indicators PDI and AECI depend on many factors like the actual lighting class, road profile arrangement, width of carriageway and sidewalks, type of the light source, quality of optics and position of lamp in luminaires (through photometric data of luminaires), etc. In case of AECI, switching and control profile may strongly affect the value of this indicator. Assuming the lighting system is optimized to target photometric parameters, lighting designs may differ in energy performance. The lower is the value of PDI and AECI, the better energy performance.

Values of energy performance indicators PDI and AECI presented in this annex are based on numerous calculations of optimized lighting systems for different combinations of road profiles, lighting classes, light source types and luminaires that are common in practice. The values should not be used as benchmarks, they are intended to create an imagination on absolute values of the indicators and their variation and to aid how to distinguish between more and less energy efficient solutions.

Assumptions taken into for sample calculations are as follows;

• width of sidewalks and grass strips, where applicable, equals to 2 m;

• maintenance factor is set to 0,80 for all types of lamps and luminaires;

• for road reflection properties the R3 table is considered;

• mounting height is optimized within the range 5 m to 12 m (step: whole numbers);

• spacing of lighting poles is optimized and sought between 20 m to 60 m (step: 1 m);

• arm overhang is ranged from 0 m to 2 m with the (step: 0,5 m);

• luminaires are not tilted;

• annual operation time 4 000 h at full power.

Arrangement of the lighting system is generally single-sided and for some situations with wider carriegeway an opposite arrangement is selected. For each calculation, the lighting system geometry is optimized with preference given to the spacing in order to enlarge the illuminated area as much as possible and to have thus the energy performance indicators as low as possible. Mounting height and arm length affects to the indicators only indirectly.

Luminaires used in calculations cover the possible options. Low-cost or sophisticated luminaires incorporate reflecting diffuser or high-quality smooth or faceted reflectors, respectively. Lamp types comprise ellipsoidal and tubular high-pressure sodium lamps, mercury lamps, metal halide lamps and LEDs of different wattages. Lamp position in the luminaire, where adjustable, is optimized and not taken as an option.

NOTE Calculations are based on lighting products (luminaires) available in Ql/2014.

A.3.2 Two-lane road for motorized traffic (road profile A)

Table A.l — Typical values of the Power Density Indicator D_Pin mW-lx^-nr²for road profile A