APPLICATION OF ROAD LIGHTING ENERGY EFFICIENCY EVALUATION SYSTEM IN PRACTICE

Size: px

Start display at page:

Download "APPLICATION OF ROAD LIGHTING ENERGY EFFICIENCY EVALUATION SYSTEM IN PRACTICE"

Roberta Ryan
6 years ago
Views:

1 APPLICATION OF ROAD LIGHTING ENERGY EFFICIENCY EVALUATION SYSTEM IN PRACTICE Pracki, P. 1, Jägerbrand, A.K. 2 1 Warsaw University of Technology, Institute of Electrical Power Engineering, Lighting Division, Warsaw, Poland, piotr.pracki@ien.pw.edu.pl 2 Swedish National Road and Transport Research Institute VTI, Stockholm, Sweden, annika.jagerbrand@vti.se Abstract The aim of this paper is to introduce the energy efficiency evaluation system of road lighting for roads with vehicle traffic. The most important information regarding the proposed road lighting energy efficiency system is given. The subsequent stages of the road lighting energy efficiency evaluation are indicated with some detailed considerations. The energy efficiency classifications based on normalised power (energy) density and power (energy) density are presented as well. Examples of lighting energy efficiency evaluation to show the application of the system for selected streets in Stockholm and Warsaw are presented. Keywords: Road lighting, Energy efficiency 1 Introduction The energy efficiency should be an important part of any lighting design and verification. Boyce et al. (2009) suggest that there should be an agreed metric for road lighting energy efficiency in order to promote more energy efficient road lighting. However, there is currently no commonly agreed system of energy efficiency evaluation for road lighting although the European proposal is advancing (forthcoming EN ). In this paper the proposed system of energy efficiency evaluation is based on the comparison of lighting energy efficiency measures for evaluated and reference objects. The evaluated object may be a single road or groups of roads. The system applies to situations with vehicle road traffic, where ME road classes (luminance criteria) are used (CIE 2010). Main objectives of using the energy efficiency evaluation should be to identify areas on the road where improvements are necessary and results in energy efficiency improvement for the whole evaluated object. The energy efficiency evaluation can be used on both planned and existing road lighting systems. The energy efficiency evaluation may be conducted on the lighting design stage (on the ground of the lighting design results) and on the lighting verification stage (on the ground of the lighting design, inventory of the lighting installation and field lighting measurements). The range of the energy efficiency evaluation comprises the following steps: Identification of lighting parameters for evaluated object Calculation of lighting parameters for evaluated object Determination of lighting parameters for reference object Calculation of lighting parameters for reference object Energy efficiency evaluation of the evaluated object In the progress of conducted research the measures for lighting energy efficiency were adopted and described. The measures based on the power (Pracki, 2010a): road lighting power density and normalised power density, and energy (Pracki, 2010b): road lighting energy density and normalised energy density, were adopted for the energy efficiency evaluation. The classifications of road lighting energy efficiency (Pracki, 2011), road lighting power and energy calculation procedures and recommendations corresponding to the road

2 lighting energy efficiency evaluation were introduced as well (Pracki, 2012). Some of these results are presented in this paper. 2 Energy consumption for road lighting The first stage of the road lighting energy efficiency evaluation is the identification of parameters, corresponding to road lighting, for the evaluated road. For each road the following parameters should be determined: The road width RW [m], luminaire spacing S [m] and area of the illuminated road A [m 2 ] The power of each luminaire P [W] Numbers of each luminaire type n The average luminance of road surface L [cd/m 2 ] Time of road lighting operation t [h/y] Then, for each road lighting installation the following parameters should be calculated: The installed power load P R [W] The installed power density P D [W/m 2 ] The normalised power density P N [W/m 2 cd/m 2 ] The energy consumption W R [kwh/y] The energy density W D [kwh/(m 2 y)] The normalised energy density W N [kwh/(m 2 y) cd/m 2 ] In practice the calculations are done for the spacings and for the reference time of operation. The calculation of the installed power load should be done for one, representative spacing and for 1 km of the road. Thus, the calculation algorithm differs depending on luminaire layout. The difference in calculations is small and results from the number of luminaires that determine the illumination of the road spacing. The illumination of a road spacing depends on luminous flux (power) of: one luminaire for single sided layout, two luminaires for staggered and opposite layouts. This is the result of luminous intensity distribution of road lighting luminaires and their locations in each layout. It is illustrated in figures 1-3. Figure 1 Location and luminous intensity distribution of luminaires in single sided layout Figure 2 Location and luminous intensity distribution of luminaires in staggered layout

3 Figure 3 Location and luminous intensity distribution of luminaires in opposite layout Knowing the number of luminaires affecting the spacing illumination one may easily calculate the installed power load for the spacing and for 1 km of the road, as well as the installed power density and normalised power density. In this paper, we used examples of road lighting in Stockholm (Jägerbrand & Carlson, 2011) and Warsaw and evaluated their energy efficiency. Depending on available data and needs, time of road lighting operation may be determined differently (on yearly, monthly, daily, hourly calculations). For the purpose of this paper the reference time of road lighting operation was assumed. What more such assumption was acceptable because there was no lighting control used and full installed power was used each day of the year from the sunset to sunrise. In figures 4 and 5 the length of night and day period for each month of the year for Stockholm and Warsaw is presented. Figure 4 Number of hours at night and day for Stockholm Figure 5 Number of hours at night and day for Warsaw

4 The length of night period is: about 4250 h for Stockholm and about 4280 h for Warsaw. For the purpose of this paper and evaluation of energy efficiency purposes the same lighting operation time, 4200 h was assumed. For more detailed assessments the energy consumption should take into consideration the differences in day and night periods for each month of the year (e.g. longer night period in Stockholm in winter and longer day period in Stockholm in summer in comparison to Warsaw). The calculations of energy consumption for road lighting purposes should be done for luminaire spacing and 1 km of road. 3 Evaluation of road lighting energy efficiency The evaluation of road lighting energy efficiency may be based on different criteria. Reference object should be the least energy efficient (Pracki, 2012). In the progress of research four classifications of road lighting energy efficiency (RLEEC Road Lighting Energy Efficiency Class) were proposed. These classifications are based on: normalised power density P N table 1, power density P D table 2, normalised energy density W N table 3, energy density W D table 4. Table 1 Energy efficiency classification for the road lighting based on the normalised power density P N [W/m 2 cd/m 2 ] RLEEC A The most energy efficient 0,2 B Very energy efficient (0,2-0,4> C Energy efficient (0,4-0,6> D Immediate energy efficient (0,6-0,8> E Low energy efficient (0,8-1,0> F Very low energy efficient (1,0-1,2> G The least energy efficient > 1,2 P N Table 2 Energy efficiency classification for the road lighting based on the power density P D [W/m 2 ] RLEEC ME1 ME2 ME3 ME4 ME5 ME6 A 0,4 0,3 0,2 0,15 0,1 0,06 B 0,4-0,8 0,3-0,6 0,2-0,4 0,15-0,3 0,1-0,2 0,06-0,12 C 0,8-1,2 0,6-0,9 0,4-0,6 0,3-0,45 0,2-0,3 0,12-0,18 D 1,2-1,6 0,9-1,2 0,6-0,8 0,45-0,6 0,3-0,4 0,18-0,24 E 1,6-2,0 1,2-1,5 0,8-1,0 0,6-0,75 0,4-0,5 0,24-0,30 F 2,0-2,4 1,5-1,8 1,0-1,2 0,75-0,9 0,5-0,6 0,30-0,36 G > 2,4 > 1,8 > 1,2 >0,9 > 0,6 > 0,36 Table 3 Energy efficiency classification for the road lighting based on the normalised energy density W N [kwh/(m 2 y) cd/m 2 ] RLEEC W N A The most energy efficient 0,84 B Very energy efficient (0,84-1,68> C Energy efficient (1,68-2,52> D Immediate energy efficient (2,52-3,36> E Low energy efficient (3,36-4,20> F Very low energy efficient (4,20-5,04> G The least energy efficient > 5,04

5 Table 4 Energy efficiency classification for the road lighting based on the energy density W D [kwh/(m 2 y)] RLEEC ME1 ME2 ME3 ME4 ME5 ME6 A 1,68 1,26 0,84 0,63 0,42 0,25 B 1,68-3,36 1,26-2,52 0,84-1,68 0,63-1,26 0,42-0,84 0,25-0,50 C 3,36-5,04 2,52-3,78 1,68-2,52 1,26-1,89 0,84-1,26 0,50-0,76 D 5,04-6,72 3,78-5,04 2,52-3,36 1,89-2,52 1,26-1,68 0,76-1,01 E 6,72-8,40 5,04-6,30 3,36-4,20 2,52-3,15 1,68-2,10 1,01-1,26 F 8,40-10,08 6,30-7,56 4,20-5,04 3,15-3,78 2,10-2,52 1,26-1,51 G > 10,08 > 7,56 > 5,04 > 3,78 > 2,52 > 1,51 The examples of lighting energy efficiency evaluation for roads in Stockholm (ceramic metal halide lamps) are: 1 - Dag Hammarskjölds väg, 2 Valhallavägen, 3 Artemisgatan and in Warsaw (high pressure sodium lamps): 4 Panny Wodnej, 5 Budowlana, 6 Drawska. The data necessary to conduct the evaluations for the roads in Stockholm and Warsaw are presented in table 5. Table 5 Road, lighting and energy efficiency parameters for the evaluated roads in Stockholm and Warsaw No RW H S Lamp P L P R P D P N W R W D W N 1 8,0 8,0 30,0 CMH 108 0, ,45 0, ,89 2,30 2 8,0 8,0 24,0 CMH 108 0, ,56 0, ,36 2,63 3 6,0 6,0 21,6 CMH 79 0, ,61 0, ,56 3,71 4 7,0 9,4 35,4 HPS 170 1, ,69 0, ,88 2,22 5 7,0 10,9 33,7 HPS 170 1, ,72 0, ,03 3,03 6 7,0 9,3 29,2 HPS 170 1, ,83 0, ,49 2,33 Depending on the evaluation criterion the road lighting energy efficiency may be different. Let s consider the first opportunity of the energy efficiency evaluation, based on the normalised power density criterion. According to the classification in table 1, the analysed roads are classified as shown in the third column in table 6. Let s consider the second opportunity of the energy efficiency evaluation, based on the power density criterion. According to the classification in table 2, the analysed roads are classified as shown in the last column in table 6. Table 6 Lighting energy efficiency evaluation for the analysed roads Criterion of road lighting energy efficiency evaluation No Normalised power density Power density P N RLEEC P D ME class RLEEC 1 0,55 C 0,45 ME4 C 2 0,63 D 0,56 ME4 D 3 0,88 E 0,61 ME5 G 4 0,53 C 0,69 ME3 D 5 0,72 D 0,72 ME3 D 6 0,55 C 0,83 ME2 C

6 It is easily seen that in case of two roads, numbers 3 and 4, different energy efficiency classes were received, depending on the criterion used. The evaluation of energy efficiency on the ground of power density includes over-illumination of the road surface (higher luminance of the road surface that required by the standard). The evaluation of energy efficiency on the ground of normalised power density does not include this over-illumination. In case of road 3 the luminance is 38% higher that recommended one and in case of road 4 the luminance is 30% higher than recommended. The energy efficiency evaluation based on energy density and normalised energy density would give the same results as if conducted on the ground of power density and normalised power density respectively because in the analysed cases the total power load of lighting installation is used all the night period during the year. 4 Conclusions The evaluation of lighting energy efficiency should be based on the installed power density (the energy density) criterion. The normalised power density (the normalised energy density) is a useful, complementary measure of the lighting energy efficiency evaluation. On the one hand, the normalised power density indicates high energy efficiency of a new lighting installation but may lose information that may be the result of over-illumination. On the other hand, the normalised power density indicates low energy efficiency of a lighting installation that is maintained at a luminance lower than recommended. Thus, it seems that the use of the normalised power density criterion for the energy efficiency evaluation purposes requires some knowledge on the included measures in order to make correct evaluation. The evaluation of lighting energy efficiency should be a part of any lighting design and any lighting verification. For the energy audit purposes it should include the lighting conditions evaluation. References BOYCE, P.R., FOTIOS, S., and RICHARDS, M Road lighting and energy savings. Lighting Res. Technol., 41, CIE CIE 115:2010. Lighting of Roads for Motor and Pedestrian Traffic. Vienna: CIE. JÄGERBRAND, A., and CARLSON, A Potential för en energieffektivare väg- och gatubelysning: jämförelse mellan dimning och olika typer av ljuskällor. VTI Report 722, Linköping, Sweden. PRACKI, P. 2010a. Potencjal energetyczny oswietlenia. Przeglad Elektrotechniczny, 1/2010, PRACKI, P. 2010b. Dynamika energetyczna oswietlenia. Przeglad Elektrotechniczny, 3/2010, PRACKI, P A proposal to classify road lighting energy efficiency. Lighting Res. Technol., 43, PRACKI, P System oceny efektywnosci energetycznej oswietlenia wnetrz i drog. Warsaw: Oficyna Wydawnicza Politechniki Warszawskiej.

Abstract. energy efficient tunnel lighting solutions 2

Abstract. energy efficient tunnel lighting solutions 2 Abstract The tunnel lighting environment has evolved significantly in recent years. Not only has LED technology entered the tunnel lighting world but the control of the different systems available in the