guide sl eng.pdf

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good PRACTICESGUIDE FOR IMPLEMENTATION OF PROJECTS

FOR ENERGY EFFICIENCY IN STREET LIGHTING

The present Guide has been worked out in the framework of the project "Energy Efficiency Strategy to Mitigate GHG Emissions.Energy Efficiency Demonstration Zone in the city of Gabrovo, Republic of Bulgaria", financed by the Global Environment Facilitythrough the UNDP. It offers a summary of the experience accumulated in the course of implementation of the Demonstration Project"Energy Efficiency Reconstruction of the Street Lighting System in Gabrovo", as all as that of similar projects implemented in othermunicipalities throughout the country.The Guide is the product of the joint efforts of leading experts in the field of lighting equipmentand automation, as well as consultants with practical experience in maintenance and construction of efficient street lighting systems.In a special section under the title Good Practices are presented successful projects, implemented in member-municipalities of theMunicipal Energy Efficiency network EcoEnergy, as well as examples from the European practice.

MU

NICIPA

LITIESA

NDEN

ERGY


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EnEffect is a non-profit NGO, founded in 1992, with the aim to support the efforts of the central and localauthorities for attainment of sustainable development of the country through more efficient energy use.

To contribute to the formulation of a policy for efficient use of energy resources at all management levels.

To support local institutional and human capacity building as a prerequisite for initiation, developmentand implementation of energy efficiency programs.

To promote the development of a local market for energy saving technologies, products, materials andservices.

To assist the exchange of experience and information aimed at improvement of energy efficiency.

Overcoming of all barriers to energy efficiency in Bulgarian municipalities and creation of incentivesfor energy conservation.

Development and management of investment and demonstration projects for energy conservation.

Development of municipal and regional energy efficiency programs.

Provision of education and training in the field of rational use of energy.

Collection, processing and distribution of information on energy efficiency.

EnEffect is acting as Secretariat of the Regional Network for Efficient Use of Energy and WaterResources in Southeast Europe (RENEUER). Members of RENEUER are municipalities, NGOs andcompanies from Albania, Bosnia and Herzegovina, Bulgaria, Macedonia, Moldova, Romania,Chroatia and Serbia and Montenegro.

EnEffect is acting as Secretariat of the Municipal Energy Efficiency Network EcoEnergy, whose mem-bership by 2003 comprises 159 municipalities as member minicipalities or associated members.

EnEffect is part of a network of similar energy efficiency centers in Poland (FEWE), the CzechRepublic (SEVEn), Russia (CENEf), China (BECon) and Ukraine (ArenaECO).

Energyefficiencyforsustainable

development

PARTNERS AND DONORS

OBJECTIVES

PR IOR I T I ES

State bodies, local authorities, research and training centers, univerities, companies and NGOs inBulgaria. Consultancy companies, institutes and NGOs from Europe and the USA. The GlobalEnvironment Facility, the US Agency for International Development, the European Commission, theUN Economic Commission for Europe, the United Nations Development Programme, the RegionalEnvironmental Centre, West European governments.

NATIONAL AND INTERNATIONAL NETWORKS

For contacts:Center for Energy Efficiency EnEffect

www.eneffect.bg

Tel. (+359 2) 963 1714, 963 0723,

963 2169; Fax (+359 2) 963 2574

E-mail:

[email protected] address:

1606 Sofia, P.O.Box 85

Office: 1164 Sofia,

1, Hristo Smirnensky Blvd., fl. 3


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Guide for Implementation of Projects for Energy Efficiency in Street Lighting | 3

GUIDE FOR IMPLEMENTATION

OF PROJECTS FOR ENERGY EFFICIENCY

IN STREET LIGHTING

The present guide has been developed as part of the project "Energy Efficiency Strategy to Mitigate

Greenhouse Gas Emissions. Energy Efficiency Demonstration Zone in Gabrovo", funded by the Global

Environmental Fund through the United Nations Development Programme.The guide is based on the experi-

ence gained during the implementation of the Demonstration Project for Energy Efficiency Improvement of the

Street Lighting in Gabrovo, as well as on the experience from similar projects in other Bulgarian municipalities.The separate chapters have been developed by leading specialists in the field of lighting engineering and

automation, and by consultants with practical experience in the maintenance and construction of efficient

street lighting systems.

The guide follows the implementation stages of energy efficiency projects - from the selection of norms,

through the audit of the existing condition and the identifying of energy efficiency measures, up to the selection

of the most feasible lighting fixtures from economic and technical point of view. Some aspects of the efficient

maintenance of the street lighting systems and the potential options for funding that kind of projects have been

considered, too.

The guide is targeting municipalities that will be implementing energy efficiency street lighting projects, and its

aim is to assist the city managers and experts when fulfilling such projects. The guide is not supposed to pro-

vide all necessary information and knowledge. On the contrary, it rather provides instructions where and how to

find additional consultation, what part of the job the municipalities can do by themselves, and when they needto contract specialized companies and consultants.The trend in Bulgaria being towards transferring the opera-

tion and maintenance of the street lighting to the municipal authorities, we hope that the present Manual will be

of help to the local governments.


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4|good practices

The street lighting has an important impact on the life of the modern man. The

artificial lighting provides conditions for performing twenty-four hour activities.

Good street lighting is an important prerequisite for the ensuring of safe evening

and night traffic, increased traffic capacity of the street network, improved safety

and confidence of pedestrians and reduction of crime rate.

ROAD ACCIDENTS AND STREET LIGHTING

One of the main functions of the street lighting is to ensure the safe evening and

night traffic of cars and pedestrians and create conditions for increasing the traf-

fic capacity of the street and road network.

Road accidents are a major problem of modern transport. A lot of accidents

occurs during evenings and nights, when 25% of the automobile traffic takes

place. The number of the live casualties during that period almost equals the

casualty number falling on daytime, when 75% of the traffic takes place.

The total annual length of the dark part of the day, when artificial lighting is need-

ed, is 4200 hours. Researches in different countries point at a 1.5 times increase

of the accident rate during dark-time periods.

The Traffic Police Department of the National Police Service in Gabrovo conduct-

ed a research based on the police records for 4000 road accidents of 1994,

1995, 1996, 1997 and 1998, concerning road accidents that happened during

night hours and in daytime. Figure 1 shows the number of road accidents in

Gabrovo, that have caused material damage, during night and day time for

1994, 1995, 1996, 1997 and 1998. From the analysis of the results it is evident

that:

- 21-23% of the total number of road accidents in Gabrovo happen during dark

hours;

- road accident rate is highest during the winter nights - from October till

February - 26 to 36 %;

- road accident percentage is also higher at early night and morning hours of low

visibility - at dusk and dawn.

The high accident percent during the dark hours in Gabrovo corresponds to sim-

ilar data from other countries, according to Paper No. 8 of the International

Lighting Commission. As per the statistics in Germany, when the illuminance is

reduced by 50%, the road accidents number increases by 30%, and the number

of the lethal accidents - by 50%. Figure 2 shows, by graphs, the relationship of

accidents number in dark hours and daytime as a function of the roadway lumi-

nance.

All that evidence preconditions the need to focus on considering and assessing

the street lighting as a substantial factor for the reduction of road accidents in

darkness periods.

CITIZENS' SAFETY AND STREET LIGHTING

Ensuring citizens' safety is the main function of street lighting in the residential

areas, at streets within them and and in small towns with low car traffic.

According to statistics in Germany, when 50% of the street lighting is switched

off, the house breakings increase by 65%, hooliganism increases by 25%, and

car thefts - by 13 % (figure 3).

Data from the Gabrovo Police Department for the years 1995, 1996, 1997 and

1998 have been sorted and analyzed for the filed criminal acts that have

occurred only on the city's streets, squares, parkings and other open public

places having street lighting.

Over the total number of registered crimes for the respective year, only 26 to36% have happened on lighted open public places, streets, squares, parking

lots et al. (Figure 4). The share of those criminal acts falling on darkness hours is

80-90%.

INTRODUCTION

50% of the streetlighting switched off

Figure 3.

Citizens' safety and external lighting

Figure 4.

Crimes at public places in Gabrovo

65% more housebreakings

25% increasedhooliganism

13% more car thefts

1994

Average luminance, cd/m2

Day/nightroadaccidents

78.3 76.5

21.7 23.5

76.5

23.5

83.6

16.4

77.2

22.8

Day

Night

0

10

20

30

40

50

60

70

80

90

%

1995 1996 1997 1998

1995

92.4 89.9

7.6 10.1

82.8

17.2

82

8

Night

Day

0

10

20

30

40

50

60

70

80

90

%

1996 1997 1998

Figure 1.

Road accidents causing material

damage during night and day time in Gabrovo

Figure 2.

Dependence of the number of accidents in dark

hours and daytime on the average luminance


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STREET LIGHTING CONDITIONIN THE BULGARIAN MUNICIPALITIES

Bilyana Petkova-Chobanova, EnEffect

Guide for Implementation of Projects for Energy Efficiency in Street Lighting |5

TECHNICAL CONDITION

According to data from the National ElectricCompany (NEK) of 1999, around 1 million lightbodies have been installed in Bulgarian munici-

palities. About 90% of them use mercury lampsand are worn out. The information from the samesource, as well as from the observatons conduct-ed by EnEffect, shows that only about 30% of theinstalled lighting capacity (wattage) in the coun-try is in operation. That circumstance is due toseveral factors. On the one hand, municipalitieswere forced to switch off 60-65% of their lightinginstalled, because of their inability to pay theelectric power consumption. On the other hand,the power distribution companies operating thelighting systems did not provide for timely repairand maintenance of the light bodies, nor for reg-ular replacement of the burt-our lighting fixtures.That entails further reduction in the number ofworking lights. The operation cycle of the streetlighting systems is not efficient, either. The light-ing at streets, squares and other open areas isswitched on and off by photocells. They are notregularly cleaned, and that leads to increase inlamps' on-duty time and in power consumption.

As a result from the above circumstances, duringthe period concerned, the actual illuminance andluminance at all categories of streets in theBulgarian municipalities were much lower thanrequired, as per the country's acting regulationnorms. By that technical condition, the street light-ing failed to perform in full its purpose as a factorfor the safe traffic of vehicles and pedestrians, for

reducing crime and creating agreeable night envi-ronment in the cities.

Meanwhile, a series of municipalities undertookactivities to improve the existing condition of thestreet lighting - by implementing energy efficientsolutions and technologies. In spite of the num-

ber of obstacles (mostly related to regulationand financial issues) faced in any project imple-mention, the respective municipalities reachedsubstiantial improvement of the quality parame-ters of their street lighting and proved the highenergy efficiency potential of such projects.More than 20 energy efficiency projects havebeen implemented within the municipal energyefficiency network EcoEnergy, to which EnEffectis a Secretariat. There are also a number of proj-ects that have already been developed and areseeking funding.

Table 1 compares the condition of the streetlighting in different Bulgarian municipalitiesbefore and after implementing energy efficiencyprojects. The data show that in the given munici-palities, prior to the energy efficiency retrofit, theaverage power of a lamp was between 190 and284 W, and after the installation of the new fix-tures it is almost three times lower: between 80and 100 W. The same trend applies for the aver-age lighting load per resident: from 13-23 W/res-ident before the retrofit, it was reduced to 5-6W/resident after implementing the energy effi-ciency measures. For comparison purposes, thedata for Cork (Ireland), Kutna Hora (CzechRepublic) and Neath Port Talbot (UK) are as fol-lows: average lamp wattage of 102, 114 and 77W and lighting load per resident at 7, 15.4 and

9.7 W/resident, respectively.

The data about the street lighting condition in the Bulgarian municipalities have been collected and summarized atEnEffect since 1998 - 1999. This chapter reviews the technical condition of the street lighting systems in that period, as

well as their development during the last years. The regulatory norms relating to street lighting have been analyzed from

the point of view of the existing technicalnorms for illuminance, as well as the disputed ownership of the street lighting

systems. A survey was made about the existing conditions for and barriers to the financing of energy efficiency projects in

street lighting in Bulgaria.

Table 1. Street lighting efficiency indices

6636

5122

18 741

14 942

2717

2672

10 000

9400

94.8

73.2

63.3

50.4

60.0

59.0

60.1

56.5

1586

432

3581

1478

772

263

2168

876.5

22.7

6.2

12.1

5.0

17.1

5.8

13.0

5.3

239

84

191

99

284

98

217

93

Municipality PopulationLighting Fixtures[Number/1000

residents]

LightingFixturesNumber

Total InstalledCapacity

[kW]

Lighting Load perResident

[W/resident]

Average LampPower [W]

Gabrovo

Varna

Kardjali

Ruse

70000

296200

45250

166350

Old condition

After project implementation

Old condition


Old condition


Old condition


1 The different obstacles are reviewed in Appendix

No. 2 to the "EcoEnergy" bulletin of EnEffect, No.

1/2002: "Major Barriers for Bulgarian Municipalities in

Implemention of Energy Efficiency Projects".

2 The data are from the "Guide to the Main Issues on

the Management of Public Lighting by Local

Authorities", issued by partners from the network

"Campaign for Energy Efficiency in Municipalities"(CLEEN)


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6|good practices

REGULATORY FRAMEWORK

The quality of street lighting, as well as the opera-tion and maintenance, depend to a great extent on

the respective regulations.Technical Norms

The norm requirements for roadway luminance,uniformity (evenness) of luminance distribution,blinding index, as well as the other indices, char-acterizing the quality of the street lighting of differ-ent street categories are specified in the BulgarianState Standard (BDS) 5504-82 "Lighting of Streetsand Pedestrian Areas". Unfortunately, BDS stipula-tions changed recently from obligatory to recom-mendable - so no control applies to the lightingquality in the cities. That means, in practice, thatthe municipalities do not have any regulatory obli-gation or incentive to bring the street lighting to

regulations requirements.There are no norms in the country, to regulate thelabeling of the lighting fixtures and light sourceswith respect to their efficiency - that impedes theselection of the most appropriate and high-qualityfixtures by the municipalities that have decided toimplement street lighting projects. Often inexpen-sive, but of low quality and efficiency, light bodieswin the tenders - such lighting fixtures do not meetthe norm requirements for street illuminance andalso deteriorate the street lighting quality.

Regulations on the Ownership and Managementof the Street Lighting Systems

As per the Local Government and LocalAdministration Act, the Energy and EnergyEfficiency Act, and the Territorial Planning andDevelopment Act, the local governments areresponsible for securing efficient external artificiallighting of the public areas. At the same time,municipalities implementing projects for streetlighting efficiency, face a number of unsettled anddisputed issues related to the ownership of thelight bodies. That discrepancy came up more fla-grant, after the adoption of the Energy and EnergyEfficiency Act in 1999 and the amendment of theMunicipal Property Act.The networks and facilitiesof the energy infrastructure were suspended fromthe municipalities' ownership scope, and in the

year 2000 they were listed as assets of the newlyestablished regional power distribution compa-nies.

As municipalities cannot invest their own funds inanother's property, their efforts to introduce energyefficiency measures at street lighting and to meettheir responsibilities for securing normal externallighting are practically blocked.On the other hand,the power distribution companies are not interest-ed in introducing measures for energy efficiencyimprovement, because such measures reduce thepower consumption and hence direct incomesfrom power selling.

CONDITIONS FOR FINANCING

The acute shortage in financing is the main barrierto the implementation of street lighting energy effi-ciency projects. Municipal budgets do not plan

funds for replacement and repair of the street light-ing, so other funding sources are to be sought,such as: international programs, "soft" loans fromspecial purpose funds, bank loans.

For most of Bulgarian municipalities, bank creditsare not yet attractive as financial sources.The highmarket interest rate and the short payback termsare serious limitations for using such credits.Credits of 3- to 5-year maturity are consideredlong-term ones, while they are rated as mid-termones by the international banking. Guarantee pro-vision on bank credits is another big problem forthe municipalities. As a rule, banks require collat-eral guarantees that considerably exceed the prin-

cipal - usually 200% - while, after the acceleratedprivatization in the last 10 years, the municipalitiesdo not own realties that are attractive and accept-able for the banks.

The other sources for financing municipal projectsare not yet sufficient, and the municipalities are notwell aware of the opportunities offered by interna-tional programs.The only special purpose fund forenergy efficiency in the country was closed at theend of 1999, and now some funding for energyefficiency projects can be received only from theNational Environmental Protection Fund (NEPF) atthe Ministry of Environment and Water, and fromthe National Trust Eco Fund. Both funds, however,are targeted at environment protection, so energyefficiency is not their main priority. Municipalities'experience is quite limited in other financingmechanisms - like third-party financing or "com-modity credits" offered by the manufacturers orimporters of energy efficient equipment.

Municipal officials' insufficient qualification infinancing is a further encumbrance. Municipalitiesdo need consultancy (by outside experts) in draft-ing projects and business plans, as well as inpreparing their applications for funding from differ-ent sources.

PAYINGS FOR ELECTRIC POWER

Until 1 February 1991, there was a separate pricefor the electric power used for street lighting. ByGovernment Decree for liberalization of prices andsocial protection of the population, that price was

equalized with the price of the power used for"economic and public activities performed by thestate and municipal authorities, and by legal andphysical entities".

Equalizing the price of the electric power con-sumed for street lighting, with the price of powerused for economic activities, conflicts with thevery essence of that kind of usage. Street light-ing is a social activity and a public service thatcannot bring any direct economic output. In2002 the State Energy Regulatory Commission(SERC) introduced a separate price rate forpower payments for street lighting, which rate islower than the price rate of power for "public

needs", but the electric power is still paid atthree price rates.

To reduce their expenses for electricity, somemunicipalities have to install expensive and diffi-cult to maintain double-rate or even triple-ratepower meters. This is an efficient investment,because it pays back in several years, yet manymunicipalities cannot provide the initial fundingfor it.


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BASIC LIGHTING PARAMETERS

The luminous flux is the luminous energy emittedby one light source per unit of time (Fig. 5). Theluminous flux is designated by F and is measured

in lumens [lm]. The luminous flux of incandescentlamp 100 W is = 1300l m, of high pressure sodi-um lamp 70 W is =6600 lm, of compact fluores-cent lamp 55 W is =3000 lm.

The energy efficiency of the lamps is different.Quantitatively, it is estimated by the emitted lumi-nous flux per unit of capacity (wattage) and iscalled lamp efficacy:

! = /P [lm/W]The 70 W sodium lamp has 80 lm/W lamp effica-cy, and the mercury lamp of 80 W - 40 lm/W.

The luminous intensity is that part of the luminousflux which is emitted in a specific direction. It isdesignated by I. The unit of measure is candela[cd]. The luminous intensity of a 100 W filamentlamp is 100 cd, and of a car headlight - 50 000 cd.(Fig. 6)

The luminous flux that is emitted by one lightsource or fixture is not evenly distributed in thespace; hence the luminous intensity is different inthe different directions. If the luminous intensitiesare presented graphically in polar coordinates

with radius vectors, their ends circumscribe thephotometric surface of the lamp or the lightsource. (Fig. 7)

The intersection curve of the photometric surfacewith a meridian plane is called light distribution

curve of the liminaire. (Fig. 8) The light distributionof the street luminaires is usually asymmetric, so itis presented by a family of curves for differentmeridian vertical C-planes. (Fig. 9)

When the luminous flux diffuses in the space, itfalls on different surfaces and illuminates them.The density of the luminous flux diffusion over theilluminated surface is called illuminance. It is des-ignated by E (E = /S) and is measured in luxes[lx], 1 lx = 1 lm/m2.

Respectively, the illuminance of the street is:

- at sun's zenith during the summer - 100 000 lx

- summer cloudy sky and clear winter day -10 000 lx

- well lit streets - 10-40 lx

- moonlit night - 0.2 lx.

The luminance is the lighting value determining

our idea of illuminating the observed surface thatglows or reflects the light. It is proportional to theluminance L, which is defined in the following way(Fig.10):

L = I"/ S cos" ,

where S is the glowing surface, [m2]; I is the inten-sity of the light in the direction of the observer [cd];" is the angle between the direction of the obser-vation and the normal to the glowing surface. Theluminance is measured in cd/m2. (Fig. 11)

The light of the fixture that falls on the streetreflects partially in the direction of the driver or thepedestrian. It is accepted from them as lighting -luminance of the street. (Fig. 12)

STREET LIGHTING NORMS

Prof. Dr. Nikolay Vassilev, Technical University, Sofia,

The first step when building new street lighting or retrofitting the existing one, is to select the desired illumination level ofthe streets, squares, pedestrian areas and historical sights.The present chapter defines the basic lighting parameters and

describes the requirements of the standards regulating the illuminance level of the different categories of streets. The light-

ing engineers in Bulgaria are not unanimous on the issue concerning the illuminance norms that should apply in the coun-

try, and we do not give the answer to this question, either. Our objective is to offer information on the different decision

options, but the municipalities should select themselves the specific norm requirements, after consulting a lighting engi-

neer or the project designer in charge of the lighting engineering calculations.

Figure 5.Luminous flux

Figure 6.Light intensity

Figure 7.

Photometricsurface ofthe lamp

Figure 8.

Light-distribu-tion curves

Figure 11.Luminance

Figure 12.Definition of luminance

Figure 9.C-meridian curves system

Meridian curvesVisible surface

Light intensity l"

Luminous surface S

S1=S cos"

1800

1500

1200

900

600

300

00

Figure 10.Luminance


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8|good practices

LIGHTING CHARACTERISTICS OFTHE STREET LIGHTING

The illuminance created by a fixture k at the i pointof the street might be defined in the following way:(Fig. 13):

Eki

= I#

cos3 #/ h2

In a number of cases, the street lighting is regulat-ed and designed according to average illumi-nance. It is determined as arithmetical mean of theilluminance values of evenly distributed points ofthe street between two adjacent fixtures:

= $ i/ n,

where Ei is the illuminance created by the two clos-est fixtures to the right and to the left of the calcu-lation field at the i point of the street, and n is thenumber of the points between two neighbouringfixtures.

Additional indices, characterizing the quality of thelighting are:

- minimum illuminance of the street min- maximum illuminance of the street Emax- uniformity of the lighting, which is estimated bythe ratios min/ E min/ EmaxThe only lighting value, which is accepted directlyby the eye, is the luminance. The street's bright-ness impression is proportional to the street lumi-nance. That is why the visibility of the objects onthe streets depends on the average luminance andon the uniformity (evenness) of the luminance ofthe roadway. There is no direct proportion betweenthe luminance and the illuminance. Fig. 14 showsthe distribution of the luminance and illuminancealong the street, for the specific lighting system.

Following those considerations, the street lightingsystems are prevailingly regulated and designedaccording to their luminance.

The luminance Lki, created by the fixture k at the ipoint is calculated by the following formula:

Table 2. Street categories as per BDS

5000-10 000

2400-6400

2000-4000

2000

-

500-700

500

Street Type Street Function

PermissibleSpeed,km/h

Streets Crossed by:

Vehicles Pedestrians

Not allowedSpeedy,

transit,

non-stop

Servicing,in periods

Servicing

Servicing

Parking Traffic TypeTraffic Capacity,

no./h

MAIN CITY

NETWORK

SECONDARY

CITY

NETWORK

At different levels or regulated by traffic lights

One traffic-lights level

At different levels or traffic lights predominantly

One level, usually not controlled by traffic l ights

One level, not controlled by traffic lights

Compulsory on different levels

Speed City Highway

City Highway

City Main Street

City-District MainStreet

Main Shopping orRepresentative Street

Collection Street

Servicing Street

Square, Intersection,Other Junctions

Limited inbroadening

Allowed

The feature of the street with the highest requirements is accepted

1.5

1

1.5

1

1

0.5

1

0.5

1.5

0.5

0.25

0.6

0.6

0.6

0.5

0.5

0.5

0.4

0.4

0.4

0.4

0.4

0.4

0.4

0.3

10

10

10

15

15

20

20

Street CategoryIntergral

Uniformity U0

Blinding

indexTI

Speed City Highway

City Highway

City Main Road

City-District Main Street

Accepted are the requirements for the street withthe highest parameters, which "flows in" into thesquare or into the intersection.

Main Shopping or Prestigious Street

Collection Street

Servicing Streets

Square, Intersection,Other Junctions

light vicinity

dark vicinity

light vicinity

dark vicinity

light vicinity

dark vicinity

light vicinity

dark vicinity

Figure 13.Illuminance

Figure 14.Distribution of the luminance and illuminance along the street

Average Luminan-

ce of the Roadway

Lav, cd/m2

Longitudinal

Uniformity U1

Table 3. Norms for lighting parameters as per BDS 5504-82

100

80

70

60

-

50

30


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Lki = q %#.EkiThe lumi-nance factor

q %#!q "%!accounts forthe reflec-tion ability ofthe roads.Dependingon that abili-ty, roads areclassified infour cate-gories: RI,RII, RIII andRIV. The q %#values for

each category are given in a table. The RIII cate-

gory is the most widely used one in Bulgaria.The average luminance is determined as per thevisibility conditions for a vehicle driver (Fig. 15). Inthe case of two lanes and roadway with b, it isadmitted that the observer is placed at b/4 dis-tance from the right end of the street. The reliableroad safety requires good visibility on the part ofthe roadway that is at a distance of 60 to 160 m. Apossible obstacle on the street should be seenfrom at least 60 m distance, so that the drivercould react in time. At 1.5 m height of the observ-er, the control field (60-160 m) is seen under anangle of 1" 0.5".

The street lighting standard specifies the lightingnorm parameters for the established control field:

- average luminance L= $ Li/ n,where Li is the luminance at i point of the street,created by the fixtures; n is the number of thepoints in the control field where the L i luminancesare calculated. Usually Li are calculated only in thestreet sector that is located between two neigh-bouring fixtures, which begin in 60 m apart fromthe observer.

- integral uniformity Uo = Lmin/ L- longitudinal uniformity Ul = Lmin/ Lmax- Lmin - the minimum calculated luminance in thewhole field

Lmin and - Lmax - the minimum and maximum cal-

culated luminances on the vehicle's movementline.

Lmin, Lmin and Lmax are also determined for thesegment of the street that is between two neigh-bouring fixtures.

BLINDING EFFECT OF THE LIGHTINGFACILITY

The fixtures light the street, but at the same timethey blind the drivers and the pedestrians. As aresult, the visibility is deteriorated, and so is thesafety of drivers and pedestrians. To reduce theblinding effect, the fixtures' emission in the 80" 80- " > 70- " < 70

Q12 - takes into account the esthetic design of the luminaire

- The design and scale of the luminaire conforms with the street profile- The shape is not modern and does not conform with the street profile

Q13 - takes into account the blinding effect of the luminaire

- I# < 500 cd for # = 90 and I# < 1000 cd for # = 80- I# > 500 cd for # = 90 and I# > 1000 cd for # = 80

Q14 - takes into account the possibility for adjustment of the optical system

- Can be adjusted- Cannot be adjusted

10830

6420

86650

8105

86635

5

0

50

52

52

86

0

100

8654

100

100

50


19/40


curve of the fixture. The table shows the maximumadmissible light intensities for the angles # = 80and # = 90 as per BDS 5504-82 with respect tolimiting the blinding effect. Usually, the project ofthe lighting facility foresees supervision of thefacility's overall blinding effect - it is quantitativelyassessed by the index TI, according to BDS 5504-82 and the European norms to street lighting.

It is advisable to avoid direct falling of the emittedluminous flux over building facades, fenestrated

walls of private houses, and shop-windows - inorder to prevent lighting pollution of the respectiveambience. Lighting pollution of the environment isnot subject of supervision in Bulgaria. In WestEuropean countries, the USA and Canada, restric-tions are being set to the emissions of light upwardinto the atmosphere. For this reason, it is not rec-ommendable to use ball-shaped (spherical) lumi-naires, as over 50 % of their luminous flux is emit-ted in upward direction. Obviously, such luminairesare extremely inefficient in energy terms.

A MODEL METHODOLOGY TOASSESS THE QUALITY OF LIGHTING

BODIESProf. Dr.Nikolay Vassilev, Technical University Sofia

Table 14 shows a model system for quality assess-ment of lighting, electrical and operation parame-ters of luminaires for street lighting. The pointsassigned in the enclosed table are given as exam-ple. They may be changed for the different ten-ders, with regards to the specific conditions. Thelighting parameters of the luminaires shall beestablished by means of a statement of findingsissued by a lighting-engineering laboratoryaccredited by the Bulgarian Accreditation Agency.

In quantitative terms, the quality of the luminairesis determined by the sum of the points assigned toeach quality criterion:

Q$=Q1a+Q1b+Q2+Q3+Q4+Q5+Q6+Q7+Q8+Q9++Q10+Q11+Q12+Q13+Q14

The table does not include the light source,because the high-pressure sodium lamp has beenestablished as the most suitable one for streetlighting. The compact lamp can only be an equiv-alent for pedestrian zones, residential areas, parksand gardens. The low-pressure sodium lampshould not be used for lighting in population cen-ters because of its inappropriate light colour andinadequate colour rendering.

Light distribution is a particularly important techni-

cal and economic feature of the luminaire. It is,partially, taken into account through some of theparameters given in the table; however its overallimportance may be assessed only after the illumi-nation system has been designed. Therefore, intenders in Bulgaria this important paramerter ofluminaires is usually not taken into consideration.The bidders are required to submit calculationsregarding the implemented average luminanceand illuminance levels, the uniformity of the light-ing and the extent of blinding by the lighting sys-tem - for:

- Different categories of streets in the populationcenter

- The respective widths of street roadways, layoutconfigurations, hanging heights and distancesbetween the luminaires

- The submitted data is used to compare the extentof suitability of the suggested luminaires, withrespect to compliance with the norm requirements.

In the case of new lighting systems, the street cat-egory and roadway width are given. Calculationsare made about the maximum distance betweenthe luminaires, in observing the norm requirements

to: average luminance or average illuminance,lighting uniformity and admissible blinding extent.Obviously, the most efficient luminaire should per-mit the maximum distance of unit spacing. Such acase shall ensure the minimum of: the number ofluminaires and poles, the required investments forthem, the installed capacity, the power consump-tion and costs for its payment and the costs forreplacement of the burnt-out lamps.


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20|good practices

EFFICIENT STREET LIGHTING CONTROL SYSTEMS -NEEDS, ADVANTAGES, SHORTCOMINGS

Stoyan Andreev, Technical University, Varna

Street lighting is an important social benefit for people and takes a substantial part of municipalities' costs. The achieve-ment of reduction in lighting cost and of improved street illuminance is a rather sophisticated task. It requires various

methods and tools to be applied, to find the most efficient way of lighting switch-over control, aiming to shorten the

lights-on period.

Street lighting control can be implemented in sev-eral ways:

% Centralized lighting control for the whole city orpart of it:

- Radio-channel control,

- Network remote control.

%Local control of individual power substations:

- By electro-mechanical and electronic clocks

- By special relays and controllers with pro-grammed calendar: switching on and off in whole-night and half-night regime; switching over to amulti-rate power meter; operation in a differentregime - e.g. lights off from 00.00 a.m. until 05.00a.m.

% Control of the individual luminaires:

- By means of switch-over devices, embedded inluminaire, that provide switching over the powerfrom 150 to 100 W or from 100 to 70 W (a specialswitchable choke is required)

- By time relays, embedded in the luminaire - e.g.for half-night lights-on regime.

The most efficient control is achieved by a cen-tralized system, which allows: (i) simultaneous orconsecutive (by groups) switching the street light-ing on and off - depending on the astronomicalilluminance curve, (ii) simultaneous switchingover the price rates of the power meters measur-ing the power consumed for lighting, (iii) switch-ing off part of the lighting during night hours oflower traffic. Such type of systems is the leastcommon in Bulgaria, at present - due to the gen-eral opinion about their price being too high.However, the rapid development of technologiesin the recent years has considerably decreasedthe investments required for setting up such sys-tems and made their wide application possible.We suggest here below a description of the twomain types of centralized control systems.

Each centralized control system requires theavailability of a communication channel betweenthe central transmitter and the receivers that arelocated next to the commutation facilities forswitching the lighting on and off, and near thepower meters measuring the electricity consumedby the lighting bodies. The communication chan-nel is the physical medium, by which informationsignals are transmittted about specific actionscompleted by remote technical equipment. The

implementation of such a channel requires con-siderable investment.

The street lighting control systems can use the fol-lowing media for organizing a communicationchannel:

- conductor medium, using telephone cables

- optic-fiber conductor medium, using optic cable

- conductor medium, using power cables of thepower network

- radio channels that are implemented by meansof radio broadcasting of electromagnetic waves inthe atmosphere.

The first two ways are quite expensive, becausethey require building of the relevant communica-tion networks, which takes large investments.

The latter two ways have been and are beingused for communication between the centraltransmitter and the receivers distributed in thepopulation center. The third method of control isknown as network remote control (NRC), and thefourth is known as radio control at ultra-shortwaves (USW).

CENTRALIZED STREET LIGHTING

CONTROL BY NRC SYSTEM

The NRC system consists of a transmitterdesigned as a three-phase generator of sinusoidvoltage with sound frequency, which is mountedin the distribution substation. It is connected tobuses of medium-voltage (10 or 20 kV) by meansof isolating transformer and distribution capaci-tors. Such a transmitter is installed in each distri-bution substation that provides power supply forthe street lighting.

The transmitter is switched on and off by a conrolunit - as per a set-up program, or upon commandfrom the central station, which is located at thezonal dispatching center of the power distributioncompany. The connection between the centralstation and the control units of the transmitters in

the substations is implemented by means of aconductor telephone line.

The signals, sent by the transmitter toward themedium-voltage buses, are conducted along thethree-phase electric power network; then they aretransformed in the power substations and go intolow-voltage networks (380/220 V), to which net-works the receivers are connected. The receiversreceive the signals and perform the commandssent.

In the NRC systems the communication channel isorganized along the power cables of the cablelines.The command signals are transmitted simul-taneously in the three phases and consist in a

sequence of impulses and pauses. Each com-mand contains a different number of impulses andpauses set out in a sequence depending on theencoding information used. The receivers aretuned to receive one or several code combina-

tions, as per their capacity and the functions theyperform.

Signals about the fulfillment of the commands bythe receivers are not sent to the central station.The NRC system operates in one direction only.

Advantages and Shortcomings of the NRCSystems

Advantages:- Using the established three-phase power net-work, for the transfer of the control signals fromthe transmitter to the receivers

- High-reliability transfer of the control signalsalong the power network

- High reliability of the receiver equipment

- Multi-functionality of the receiver equipment (onereceiver can fulfill up to 8 different commands)

- Programmability of the receivers

- Centralized control of the transmitters, by thezonal dispatching center of the power distributioncompany

- Optional use for other purposes - e.g. for con-trolling the load schedule of the power network,traffic-light control, control on civil defense sites,fulfillment of individual orders, etc.

Shortcomings:

- The remote receivers at power substations maypotentially fail to work, due to low level of the con-trol impulses, especially at times of high workloadof the transformers

- All NRC systems in one population center shouldoperate at the same frequency, because the

Central control station

of the street lighting system


21/40


power networks may be supplied from differentsubstations

- A separate room is needed in the distribution

substation, to locate the transmitter, the connect-ing components and the control unit

- Qualified maintenance staff is needed, due tothe sophisticated structure of the different compo-nents

- High price

- Import equipment

- No option for feedback.

CENTRALIZED STREET LIGHTING

CONTROL SYSTEM THROUGH USW

RADIO CHANNELS

The system is composed of a central computercontrol station with a radio station for radial (not-channeled) radio transmission of encoded sig-nals, and radio receivers located in the cells forswitching the street lighting on and off, or next tothe power meters for switching the price rates.The receivers capture and fulfill the transmittedcommands. When necessary, feedback can beorganized for transmission of messages from thereceivers to the central station. The feedbackmakes the system substantially more complicatedand expensive.The radio channel is implementedby transmission-reception equipment, working inthe USW band. The working frequency that maybe used is either the frequency allocated to therelevant civil defence municipal service, or thefrequency allocated to the local power distributioncompany.

The central station consists of a PC, a control unitand a power pack. The station may transmit anunlimited number of commands, which are protect-ed by sophisticated codes for prevention of incor-rect actions by the receivers. The antenna of thereceivers is mounted on the roof of the power sub-station or on the first pole next to the power supplycell. The connection between the antenna and thereceivers is implemented by a coaxial cable.

The receivers may be organized in groups forseparate control of the lighting in different city dis-tricts or residential areas. A code is assigned toeach one of those groups.This allows consecutive

switching on of the lighting and relieves the powernetwork regime. All receivers are controlled byone central station. The number of receivers isunlimited.

The antenna of the central station is installed at anappropriate place, where it may ensure efficientradio broadcasting of the transmitted USW sig-nals and their receiving by all receivers.A suitableplace would be the dispatching center of thepower distribution company.This is also a suitableplace from another point of view. According to theEnergy Act, only the power distribution companyis entitled to switch over the price rates of thepower meters. So, potential disagreements areavoided between the municipal authorities paying

the power costs, and the power supplier. In thecase of such location, the central station shouldbe programmed to automatically transmit thecommands in compliance with the time and theastronomical illuminance curve.

It is possible to place the antenna of the centralstation on a municipal building, or elsewhere, butthen one must locate receivers at the power dis-tribution company - for supervising the time ofswitching over the price rates of power meters.

A street lighting control system through USWradio channel has been installed in Gabrovo, and

it controls 150 power substations. The whole sys-tem has been manufactured in Bulgaria. Themunicipality obtained full control over the opera-tion regime of the street lighting and is able todirectly manage its power consumption costs.

Advantages and Shortcomings of the ControlSystem through USW Radio Channels

Advantages:

- Control of all receivers by a central station

- The system is digital, allowing the use of com-plex bias/interference-protected codes

- Multi-functionality of the receivers

- The transmitter has low power transmission

- The system operation may be programmed

- The system can be started either manually, orautomatically - by photorelay, program clock orsoftware program

- The system uses allowed frequencies

- Low price

- Locally manufactured

Shortcomings:

- Temporary interference in the radio channel ispossible

- Possibility for damage of the receiving anten-nas.

Figure 20. Centralized control system through USW radio control

Power station Luminaries

Central control station

Antenna

Central control station of the street l ighting system


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MAINTENANCE OF THE STREET LIGHTING SYSTEMS

Ivan Chanev, Street Lighting EAD, Sofia

The forthcoming transfer of the ownership over the street lighting systems to the municipalities will pose to localauthorities a number of problems relating to organization, operation, and maintenance. This chapter offers an

organization model, which closes the cycle of applying to and winning a retrofit project: (i) investment, design and

construction of street lighting systems, (ii) submitting the built systems for maintenance, (iii) long-term use by the

population.

22|good practices

The effect from the retrofit of street lighting sys-tems (SLSs) has many aspects: environmentalbenefit due to reduced consumption, resp. output,of electric power; financial effect manifested inreducing the funds for power; and, perhaps themajor one, a social benefit. The implementation ofthis service to the population is doomed to failure,in case there is no maintenance system for thebuilt facilities.

The forthcoming privatization of power distributioncompanies (PDCs) will perhaps promote theresolving of a seemingly irresolvable problem - theownership over the SLSs. In their major part, thesesystems still belong to the assets of PDCs and,when de-nationalized, those assets would becomeprivately owned (and not public municipal proper-ty), which is their redetermination.

Regardless of the further development of the own-ership issue, the obligation to maintain the SLSs ingood working condition is another burden on theshoulders of municipal administrations.

The below-suggested organization model showsonly the functional aspects and does not specify

staff number. Combined staffing is possible both inhorizontal and vertical direction. Practically, this isthe municipal "umbrella" over the executive unit.

(Figure 20 )

MAIN TASKS OF THE FUNCTIONAL

ASPECTS IN THE MANAGEMENT ANDCONTROL OVER THE STREET LIGHT-

ING MAINTENANCE

Information Unit

This functional aspect may include the tasks relat-ing to monitoring the condition of the existingequipment - by performing inspections or byreceiving the signals about malfunctionings report-

ed by residents. For better objectivity, the cases of

malfunctioning should also be considered as relat-ing to equipment wear, which can be accuratelyassessed only by the keeping of respective equip-ment files (archives) - in order to get the right ideaabout the possible personal fault of an assignee.

In most general terms, the archives keep an inven-tory list with information about the number andtype of luminaires, poles and power network. Thedata about the luminaires may serve to plan thepower consumption and the approximate servic-ing time. Without those archives, it would be diffi-cult to plan the costs of the main functionalaspects - for renovation with replacement of oldluminaires, and for current and emergency main-tenance.

It will be of help, to have the inventory list accom-panied by the scheme of the streets that receivelighting from the respective street lighting panel -to make the connection between the consideredterritory and the SLS.

When organizing the information exchange, a pro-vision should be made to have all equipmentchanges promptly registered in the archives - e.g.luminaire type and capacity, configuration, resp.,capacity of the panel, replacement of a worn-outnetwork, etc. The municipal administration mayalso provide the archives to contain informationabout the replacement and current repairs of theequipment, which belongs to one panel (i.e. filingper panels), but a separate register may be kept,as well, about the replacements of lamps, lightingbodies, network, etc.

The information processing, with respect to analy-ses and forecasts, would be much easier, if a com-puter is used. With average computer literacy andwith the help of the Excel software, the data can beeasily and accurately processed as per the spe-cific purposes of the analysis.

Last, but not least, an Information & MonitoringUnit can also assume the functions of relations tothe public and the media.

Figure 20. Structural Organization Model

DEPUTY MAYOR

IN CHARGE

CHIEF EXPERT

FINANCE OFFICER

INVESTOR

HEAD OF INFOR-

MATION UNIT

MONITORING /

SUPERVISION

ARCHIVES

OPERATION

ENERGY

CONTROL

Neath Port Talbot operates a public lighting

office responsible for the maintenance of

18,000 lighting points over wide urban and

rural area. The office has permanent staff

and receives reports of faults sent in by

members of the public using a free tele-

phone number and on prepaid postcards

available at post offices. These facilities are

widely publicized to members of the public

through leaflets and information in the local

press. In addition, there is a regular night

patrol - once a fortnight in winter and once a

month in summer. All identified faults are

processed immediate ly by reference to the

database, designed specifically for that pur-

pose. The light is located and the repair

instructions issued. The whole fault repair is

then followed automatically by the database.

Normally, all routine repairs are carried out

within 4 days and urgent repairs within 2

hours.

Gathering information for the establishment

of a database is a major investment in the

cases local authority is responsible for a

large number of lighting points over a widearea. It goes without saying that the value of

a database is only as good as the data that

goes into it. The motivation of those who col-

lect the data is vitally important. Initially, the

Electricity Supply Board in Ireland used stu-

dent labour to prepare the database, howev-

er it found that the resultant database had

too many faults and a considerable amount

of data had to be re-collected. It may, there-

fore, be preferable for those, who will work

with the system, to collected the data them-

selves.


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Finance Unit

The key feature of this functional aspect is theaccountancy processing of the information aboutthe funds spent in three main areas: (1) investmentsin building new sites, and reconstruction and mod-

ernization of the existing street lighting; (2) coveringthe maintenance costs, contracted with theassignee; (3) funds for payment of the power con-sumed. By its nature, this unit is a traditional one - itis required in any business activity and has noextraordinary or strictly specific functions beyondissues on spending and accounting of funds.

Control over the Consumed Electric Power

At first glance, this activity may seem not manda-tory, as with the given installed capacity and light-ing duration the estimated consumption is easilyobtained. However, there exist a number of pre-requisites for improper or spending of funds forenergy:

- A blocked power meter and not precisely deter-mined payment "basis"

- Overrated readings in power consumption meas-urement

- Not writing off sites, which have been closeddown, or accounting of consumption for non-exist-ing sites

- Lights are on 24 hours, due to technical failure.

Besides, it is not possible to come up with accept-ably accurate forecast and analysis of the power -due to burn-out lamps or luminaires not working fordifferent reasons - so, no sign of equality can beput between installed capacity and operating

capacity, and no precise estimate of the operationhours can be given, either. The panel may be con-trolled by a clock or a photosensor, but in bothcases - because of unchanged price rate in theclock, or any meteorological circumstances - an

imprecision may occur, which, multiplied by theerror in determining the operating capacity, wouldcumulate unacceptable deviations from the actual

consumption. Therefore, the actual consumptionshould be controlled by regular checks.Practically, this means comparing, on monthlybasis, the readings stated in the bill with the actu-al readings of the power meter of each panel. Aftercoordination with the power distribution company,any non-existing sites shall be deleted from thebill, and further monitoring of the average con-sumption for each panel shall be conducted (suchmonitoring may be done on a quarterly basis).

At the discretion of the municipal government, thisactivity may be delegated to the maintenanceassignee, and the application may be supervisedby the control body of the information unit, but, to

make such a choice, the municipality should con-sider its own economic positions at the time of thecontracting.

CRITERIA FOR SELECTION OF AN

ASSIGNEE FOR MAINTENANCE OF A

SLS

"Assignee" means an autonomous organization, orcompany, regardless of whether completely orpartially municipally or privately owned. The mainmaterial and organizational parameters of theassignee shall be the following:

% The subject of activities should state an activityfor servicing low-voltage power distribution net-

works and/or street lighting networks.% To have at disposal qualified staff comprisingelectricians, who have educational background aselectricians and an obtained qualification level asinterpreted by Chapters II and III of the LabourSafety Rules for Operation of Electrical Systemsand Facilities.

% To possess platform trucks and/or ladder-trucks,which are in compliance with the Act on TechnicalRequirements to products, Chapter Five (StateGazette No. 86/1999), and with the Regulation onTechnical Supervision and Register of Equipment(Decree of the Council of Ministers No. 187 of2000, State Gazette No. 79).

% To have dispatching center, which coordinatesthe operation and repair works within the compa-ny, itself, and (when necessary) with the powerdistribution company, the municipality, etc. Thiscenter should be equipped with at least one tele-phone line.

% To be able to organize an emergency service fornon-stop operation (or as per a schedule suggest-ed by the municipality) for action taking within thetime limits stipulated by the municipality.

% To have developed job descriptions for "electri-cian servicing street lighting systems".

% To have introduced organization and instruc-

tions guaranteeing labour safety - personal pro-tection means, technological instructions for con-ducting the maintenance.

% To possess administrative, garage and ware-house facilities.

SPECIFIC CRITERIA THAT ARE SUB-

JECT TO NEGOTIATION BETWEEN

THE MUNICIPALITY AND THE

ASSIGNEEBasically, the criteria may be divided into twogroups: (1) response time in case of emergencyand as per the type of incident; and (2) financialcriteria - both in terms of estimated annual volume,and of sanctions for delayed response.The criteriafrom the first group shall be differentiated as tech-nical criteria and organizational (response-time)criteria.

By response time:

Technical criteria:

% What is meant by emergency?

- A certain number of a series of lamps are not lit

(three, four or more)- A whole branch is not lit

- A panel failure

% Type of failure

- Burnt-out lamps

- Damage at the panel

- Damage in the network

For convenience, we shall give below the results ofa study of failures of SLSs in Sofia in the period1982-1987, showing the portion of failures percomponents:

Organizational criteria - response time on the basisof combination of the above options.

% Response time means the time from receivingthe signal about the occurrence of failure untilremedy to that failure. This response time shouldalso include the technological time for transmis-sion of the signal by the dispatcher toward theemergency or operation group, as well as the time

for physically reaching the site.


At a panel

At the luminaireIn the cable networkIn the airborne networkIn external power supplyNetwork cut 6

41 %

27 %12 %11 %5 %3 %

A remote monitoring system is operated in

Besancon. The system enables collection of

data from the individual control boxes or

metering points. It measures consumption

and locates faults to groups of 10 lamps.

Information is transmitted back to a centralcomputer via a mains signal.

6 Those are cases of failures resulting from constructionor other excavation and assembly works.


24/40

24|good practices

% The fastest response is due in cases of failuresthat cause phase condition on poles and lightingin daytime.The deadline shall not exceed 24 hours

total after the receiving of the signal.% Failure at the panel should be removed in theshortest possible time. This operation requirestechnological time of not more than 10 minutes, 2hours maximum for labour, excluding transporttime, and on the other hand, if a whole panel is notlit, this means that a whole suburb has no lighting.Therefore, in case of delay of remedy to such fail-ures, maximum sanctions should be imposed.

% The next in time limiting, is the replacement ofburnt-out series of lamps. The technological timefor that is approximately 15 minutes per lamp.

% Relatively the most difficult and requiring techno-

logical time are the network failures. In the case ofair-extruded conductors, the network shall bephysically inspected, and a detailed supervisionshall be conducted in searching for interlacing, cutoff conductor or another reason, and in the case offailure in the cable network it may be necessary todetect the failure on the spot, by using a cable lab-oratory, excavation (attended by the laboratory),muffling and another inspection for potential fur-ther damages after the remedy to the failure.Depending on the way of cable laying (e.g. underasphalt and without tube network), the failure mayrequire up to 10 working days for repair in the caseof service and collection streets, and 5 working

days in the case of main shopping or city-districtmain streets.

Financial and economic criteria

The total annual cost in most general terms isdetermined by the components labour, materialsand fuel. Under market-economy conditions, asubjective underestimation of the necessary staffmay occur, entailing difficulties, delays and eventermination of the contract. In this respect, themunicipality should find the right correlationbetween staff number and facilities that need serv-icing. Such official regulatory norms did not exist

under the centrally planned economy, and, logi-cally, not nowadays, either. Nevertheless, takingthe risk of a minor imprecision, I will quote the esti-mates developed in the period 1983-1986 for thecorrelation between the facilities and the staffequipped for servicing luminaires by using hoisttechnology.

The municipality should consider the importantissue of being aware, in advance, of the percent-age ratio of the different costs for maintenance.Wewill quote another study conducted in the late1980s, which nevertheless gives an idea about theportion of the different accountancy components.

Everything stated above leads to the conclusion,that, without a solid information database aboutthe available facilities, it will be difficult to make ahighly objective and acceptable estimate, and,respectively, to set a criterion about the total annu-al costs.

The financial sanctions imposed for failing tocomply with the technological and organizationcriteria differ substantially from contract to con-tract; however, if the ranking under the above-indicated Selection Criteria is taken into account,then specific numbers and percentages may beagreed.

CONCLUSION

The present organizational estimates are recom-mendable, but not biding. They are aimed to beof maximum possible help to the municipaladministrations in regaining the right to managethe street lighting systems. It is quite difficult tocover 100% of the problems, especially by con-sidering the specific features of each populationcenter - remoteness, terrain, funds, and last but

not least, the current condition of the facilities.However, a start should be made - in followingthe wise popular saying: "you cannot do a job,without beginning it".

The practice in managing and servicing the SLSshas so far isolated the municipalities from theactual servicing. Usually, the population puts pres-sure on local governments to resolve a problem,yet they have neither the legal authority, nor the rel-evant practical experience for that. A comfortingfact in that respect is the existence, in the last 20years, of a team, working on municipal principles,and academic circles, in particular from the tech-nical universities in Bulgaria have also focused on

the operation of street lighting systems. The avail-able knowledge is to be popularized, to be a goodprerequisite for the implementation of municipali-ties' basic activity - delivering services to theirelectorate.

Luminaires above 10 mLuminaires below 10 mCable networkAirborne networkPanels

1 person1 person1 person1 person1 person

Activities relating to Staff

790 pcs.1300 pcs.17 km50 km50 pcs.

MaterialsContracted servicesDepreciationLabourSocial security contributions

Vocational trainingand unem-ployment fundcontributionsOther costsIndirect costs

57.22%2.57%1.58%15.52%7.05%0.83%

5.33%10.03%

Costs for In % for Sofia

The Irish Electricity Supply Board in Cork

uses a portable computer technology

LITEMATE. In order to avoid the time-con-

suming processing of documents on a

paper carr ier, the Elect rici ty Supply Board

started to look for ways for its staff to do as

much as possible while they were out on

the site. The employees were provided with

a portable computer LITEMATE, whichcontains information about all the lights in

their respective area. Each operator cor-

rects all information on site and then feeds

this into the main database each evening

using a terminal unit in his house. When he

carries out a repair the computer will let

him know all the old bulbs that need to be

replaced.

The system takes some time before people

get used to it, however now the workers

are much happier using the portable

device than having to correct information

in the office after work.

Workvolume


25/40


CURRENT OPPORTUNITIES FOR THE FINANCING OFENERGY EFFICIENCY PROJECTS IN STREET LIGHTING

Dimitar Doukov, EnEffect

The payment of the electric power for street light-ing needs significant costs from municipal budg-ets. On the other hand, the achieved power sav-ings, as a result from the implementation of streetlighting energy efficiency projects, ensure pay-back within a period of 2-3 years, with reachingconsiderably higher levels of the quality indices ofilluminance. This is a reason to believe that proj-ects for retrofit of the street lighting systems areboth strongly needed and profitable. All municipal-ities are expected to implement such projects inthe near future.

The approach to funding and implementing the

projects for street lighting retrofit should take intoaccount the existing double-sided interpretationof the ownership over street lighting systems. Thenew lighting bodies, bought and installed by themunicipality, remain in most cases municipalproperty, and the street lighting system as a wholeremains an asset of the power distribution com-pany.

An important component of the system for fundingenergy efficiency projects in street lighting, is thepossibility for the Power Distribution Company toparticipate by "free of charge" assembly work atthe retrofitting. The assembly work will actually befinanced through funds for annual repairs.Although the Power Distribution Company will nothave direct profit form the invested funds in thefirst year, in the next years it will spend consider-ably less funds for the system maintenance,because the equipment will be new and coveredby warranty. This is a sufficient incentive to havethe Power Distribution Company attracted to takepart in the project.

The funding of projects for street lighting retro-fitting is most often ensured through bank loan.This is a relatively accessible source of funding,because in Bulgaria there is considerable experi-ence in the financing of such projects by banks.The project assessment does not constitute atechnical difficulty for the bank, and the risks relat-

ing to the project implementation are minimal.Through bank loans from the United BulgarianBank has been financed, so far, the retrofitting ofthe street lighting in Pazardjik, Pernik, VelikoTarnovo, Popovo and other cities.

The retrofitting of street lighting systems can befunded through the issuing of municipal bonds.This method of financing is suitable for large citieshaving large needs in financial resources.The verypreparation and issuing of the municipal bondsrequires quite long time and high costs. In spite ofthe relatively more profitable financial resource,which may be attracted through municipal bondsissue, the risks related to the implementation of the

issue are rather high. This source of financing isrecommended only to municipalities having largeown revenue and first-class credit rating. At theend of 2002, the Varna municipality issued its firstmunicipal bonds, which were used for financing

the project for reconstruction of the city's streetlighting. The nominal value of the Varna municipalbonds issue amounted to EUR 3 million. The pay-ments on the issue will be effected in three equalinstallments in each of the following three years.The interest coupon of the bonds is set at 9%,which for euro-denominated bonds ensured a highprofit. The Varna municipality bonds were market-ed with private help. An invitation for purchase ofthe issued bonds was sent out to approximately 50potential investors, which relieved the administra-tion from preparing a brochure for the bonds andfrom the need to obtain approval from the StateSecurities Commission. The municipality conduct-ed in advance a procedure for obtaining a creditrating from the international agency Moody's, as aguarantee of f inance stability.

Through a purchase under leasing conditions, therequired equipment for the projects for street light-ing retrofit can be supplied. A great number ofmanufacturers and vendors of lighting bodies offerthis option. Leasing may be also contracted with aspecialized leasing company. The purchase underleasing conditions has a number of advantages. Aleasing-based purchase is a flexible option, andthe costs for it are deducted before taxation. Theleasing payment installments are equal in amountand are set at an unchanging interest rate. Leasing

is a tool for operation costs, and not for capitalcosts, although the leasing period may be as longas 3 years (and up to12 years, in some countries).However, the leasing period is never longer thanthe lifetime of the equipment. The assets are com-pletely paid up within the leasing period, and after-wards there is usually an option for further buyingat BGN 1.

Commercial (consumer) credits are another formof leasing. The manufacturer (vendor) of theequipment grants the commercial credit tofinance the purchase, and he postpones the dateon which the payment will become due, or allowspayment in installments. From the consumer's

point of view, this looks as a purchase withdeferred payment. The sellers and distributors ofgoods and equipment in many cases are ready tosell on credit. This method of financing, however,is typical for relatively small projects. For the deliv-ery, usually, the price is agreed as a lump sum,without separately charging interest and otherpayments.Yet, those charges are practically oftencalculated under the form of a higher sale price.The convenience of this type of transactions isthat in some of them more favorable prices can beagreed for the customer, as well as conditions fordeferred payment at minimum interest, or with nointerest at all.

For the municipalities, which do not have suffi-cient own funds and specialists for conductingenergy efficiency retrofit of street lighting, theenergy service companies are a suitable alterna-tive. The energy service companies are highly

specialized firms, which have good engineeringcapacities and usually also have a stable financialpartner - a bank or another financial institution. Inmany cases they are divisions and subsidiaries offamous manufacturers of energy efficient equip-ment, or of manufacturers of control equipment forindustrial processes or for lighting of buildingsand external spaces. The financial mechanismapplied by the energy service companies isbased on paying up the capital costs for the proj-ect implementation - from the savings achievedby the project.This funding mechanism for energyefficiency projects has the advantage of relieving

the site's owner from the risk and from commit-ments related to funding and implementation.Certainly, that happens for the account of increas-ing the price of the investment by the costs forcovering the credit risk and the profit of the ener-gy service company.

Although the involvement of energy service com-panies is appropriate in retrofit projects for streetlighting systems, this option has rather seldom usein Bulgaria - the main reason being the relativelycomplicated and long period of the negotiations,that is supplementary encumbered by the partici-pation of the Power Distribution Company in theownership over the systems.

Which financing mechanism should be applied tothe projects for street lighting retrofit, depends tothe largest extent on its feasibility and on the priceto be paid for the granted financing. It would berecommendable to firstly study all the possibilitiesfor obtaining a bank loan, and, on the basis of thatstudy, to compare the alternative options. It is alsoimportant to keep in mind, that, in any case, it isbetter to have an energy efficiency project imple-mented, regardless of the cost of the creditresource, because without the project implemen-tation the municipality would incur much largercosts.


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Prof. Dr. Nikolay Vassilev

Professor at the Technical University (), Sofia, Faculty ofElectrical Engineering, Department of Electric Power Supply,Electrical Equipment and Electrical Transport. Head of the R&Dand Testing Laboratory of Lighting at the TU, Sofia. Chairman ofHonour of the National Committee of Lighting, as well as Headof the Department of Outdoor Lighting, of the InternationalLighting Commission. He has graduated at the TU, Sofia, withmajor "Electrical Networks and Systems" and also received atthe TU a PhD degree in the field of street lighting. Obtained theacademic ranks of Associate Professor and Professor in"Industrial Lighting" and "Power Supply of Industry Sites". Hasseveral textbooks and manuals published in the above-men-tioned fields, as well as over 250 research papers. Has been theresearch tutor to 15 post-graduate students, who successfullydefended their PhD theses. His large project-design activity

relates to 50 major projects, incl. projects of national impor-tance. Has participated in a great number of international andnational congresses, conferences, seminars and workshops.His activities in making popular science and technology issuesare extended to a multitude of specific subjects.

Assoc. Prof. Dr. Stoyo Platikanov

Graduated at the TU, Sofia, with major "Electric Power Supplyin Industry". PhD degree in the field of lighting engineering(1979). Presently, Associate Professor at the Department ofElectric Power Supply and Electrical Equipment, at theTechnical University, Gabrovo. At the TU-Gabrovo he foundedthe Lighting Engineering Laboratory. Research tutor to post-graduate students. R&D activity in lighting, electrical and solarphotovoltaic systems. Has a great number of research paperspublished, in Bulgaria and abroad, and has participated ininternational R&D projects. As of 2001, he is Chairman of theNational Lighting Committee in Bulgaria, and member of theManagement Board of the Federation of the Scientific andTechnical Unions in Bulgaria. Heads a team of specialists,developing projects for energy efficiency retrofit of street light-ing - their projects have already been implemented in 15Bulgarian cities - Varna, Gabrovo, Pazardjik, Kardjali, Shumen,Dobrich, Veliko Tarnovo, Bourgas, Yambol, Stara Zagora etc.Assoc. Prof. Dr. Platikanov is a regular participant in the proj-ects of EnEffect on implementing energy efficiency solutions inBulgarian municipalities.

Sen. Asst. Prof. Plamen Tsankov

Graduated in the major "Electric Power Supply and ElectricalEquipment" and since 1997 works as Assistant Professor inelectric power subjects at the Department of ElectricalEngineering and Electronics of the Technical University,Gabrovo. Develops a PhD thesis in lighting engineering. HisR&D activities are in the filed of lighting engineering, electricpower supply and renewable energy sources. Takes part in R&Dprojects of the European Union. In 1999 received Consultant'sCertificate in Municipal Energy Planning, and in 2001 complet-ed post-graduate studies in "Energy Management andRenewable Energy Sources" at the Technical University inBerlin. Member of a team from the Lighting EngineeringLaboratory of the Technical University, Gabrovo, developing

projects for energy efficiency improvement of the street lightingin Bulgarian municipalities. As lecturer and consultant on streetlighting isues, takes part in 5 training courses of EnEffect in"Municipal Energy Planning and Management".

Assoc. Prof. Dr. Stoyan Andreev

Head of the Department of Power Engineering at the TechnicalUniversity, Varna. In 1971 graduated the Kiev PolytechnicalInstitute, with major "Automation of Power Generation andDistribution". In 1981, at at the same institute he obtained a PhDdegree by his thesis "Research and development of a method-ology about the structure of an information control system forpower distribution network". In 1974 starts work as AssistantProfessor at the TU-Varna, in 1985 is promoted to AssociateProfessor, and in the periods from 1987 to 1993 and as of 1999is a Department Head. Member of: Union of Scientists, Scientificand Technical Union of Power Engineers, and BulgarianNuclear Society.

Ivan Chanev, Engineer

In charge of technical administration at Street Lighting EAD,Sofia. Graduated the Technical University, Sofia, with major"Power and Electrical Equipment Supply of Industry Sites".Completed post-graduate studies in Lighting Engineering atthe same university. In 1980 starts work as Project Designer atDistrict "Street Lighting". Has been promoted to Head ofOperations, Head of Technical Research Department etc. Thechapter Maintenance of the Street Lighting Systems evi-dences his more than 20 years of experience in projectdesign, operation and maintenance of the street lighting sys-tems in Sofia.

Dimitar Doukov

Graduated the University of National and World Economy, Sofia.

Has worked as Economist at the Ministry of RegionalDevelopment and Housing Policy, as Coordinator at the USAIDprogram "Local Self-Government Reform", and as DepartmentHead at the Foreign Investment Agency. At present, he is SeniorExpert at EnEffect and heads reaseach works in the field offinancing energy efficiency projects in municipalities.

Bilyana Petkova-Chobanova

Graduated the Technical University, Sofia, with major "Automation and electronic measuring devices ". As of 1999works at the Center for Energy Efficiency EnEffect - asCoordinator of the Demonstration Project for Energy EfficiencyImprovement of the Street Lighting in Gabrovo. In 2000 leads

and coordinates the work of the assigned Working Group onthe Problems of Street Lighting in Bulgarian Municipalities,which prepared and distributed a report with specific recom-mendations for the resolving of municipalities' street lightingproblems. Keeps active cooperation with member municipali-ties of the Municipal Energy Efficiency Network EcoEnergy - inpreparing and implementing energy efficiency projects instreet lighting, as well as in disseminating the results fromthese projects.

aboutthe authors


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The Demonstration Project for Energy EfficiencyImprovement of the Street Lighting in Gabrovo ispart of the project Energy Efficiency Strategy forMitigation of GHG Emissions. Energy EfficiencyDemonstration Project in the city of Gabrovo,Republic of Bulgaria and is financed by the GlobalEnvironment Facility (GEF) through the UnitedNations Development Programme (UNDP). It wasimplemented in the period 1999-2003 under themanagement of the Center for Energy EfficiencyEnEffect.The objectives of the project were as fol-lows: to reduce the direct costs of the municipalityfor street lighting by improving its efficiency; toimprove the security of movement at night for bothpedestrians and vehicles; to create a comfortableand pleasant night atmosphere in the city; and todemonstrate technical and organizational solu-tions which might be applied by other municipali-ties throughout the country.

As a first step of project implementation, a teamof the Technical University of Gabrovo per-formed an energy audit of the street l ighting sys-tem in the city. It helped identify the baselinecondition of the system and thus created a basisfor comparison of the project results. The stud-ies conducted by the team revealed that thetotal installed capacity of the street lighting inGabrovo was 1 582 kW, while the installed streetluminaires were extremely inefficient mercurylamps. A large portion of these luminaires washeavily depreciated, and hardly 50-60% of theunits were in operation. The reason for this bad

condition was the inability of the local authorityto pay for the energy consumption, on onehand, and, on the other hand, the fact that thelocal power distribution company provided poormaintenance and delayed repair (if any) of thedamaged luminaires. Another deficiency of thestreet lighting system in the city was the ineffi-cient operation cycle, since the system wasswitched on/off by means of photocells, whichwere not regularly cleaned and hence undulyprolonged the operation time of street lamps.For the above-mentioned reasons, the lumi-

nance of the streets in Gabrovo was relativelylower than the acting norm requirements andwas quite inefficient from economic point ofview.

The next step of project implementation was theelaboration of energy efficiency solutions in sever-al options. Application of two energy efficiencymeasures was considered: (1) replacement of theexisting mercury-lamp luminaires by sodiumlamps, which guarantee maximum energy efficien-cy and long-term lifetime; and (2) optimization ofthe operation cycle of the street lighting systemthrough centralized switch-over control, introduc-tion of whole-night and half-night operation along

the city's highways and main roads, and introduc-tion of two-rate metering of the power consump-tion.

In order to determine the most appropriate lumi-naires for replacement of the old ones, a lightingengineering project was developed on the basis ofthe norm requirements for street lighting. Itrevealed that it would be possible to reduce theinstalled capacity almost threefold, which willresult in significant reduction of energy costs.

With the help of consultants, the possible optionsfor centralized control of street lighting wereinvestigated - a system for network remote controland a system for centralized control of the streetlighting by USW radio channels. The preliminaryassessment of the required investments for theintroduction of each of the systems revealed thatthe investments for network remote control were

many times higher than those for the radio-controlsystem, while the estimated effects to beachieved were almost identical. For this reasonthe selected option comprises full replacement ofthe existing luminaires by new energy efficientsodium lamps, introduction of a centralized radio-control system of the street lighting, and full shiftto metering the electricity consumption by twoscales - daytime and night price rates.Because ofthe large scale of disassembly and installationworks, as well as the time needed for procure-ment of financing, the replacement of the lumi-

naires was split into three phases - Pilot Phase,Phase One and Phase Two.

The suppliers of luminaires were selected bytenders, conducted by EnEffect or the Gabrovomunicipality, with the participation of outsideexperts and the power distribution company inGabrovo. For procurement of funding for PhaseOne and Phase Two of the replacement of lumi-naires, the municipality, with the assistance ofEnEffect, drafted an application for a free grantfrom the National Environmental ProtectionFund. The funding was provided in the form ofa 0-interest loan - the municipality decided totake up this additional financial burden and

proceed with the implementation of the project.The installation of the luminaires was per-formed by Electrorazpredelenie (PowerDistribution) Gabrovo as in-kind contribution tothe project.

On the basis of the conducted tender the compa-ny Diagalog Tekhnika Ltd, Varna, was selected assubcontractor for the system for centralized con-trol of street lighting. Currently, the system com-prises 250 power substations in the city and per-forms the following functions: (1) switching thesystem on/off under an operation schedule, pre-programmed by the municipality, (2) switching ona half-night regime for part of the power substa-tions during the late night hours, and (3) switchingover the price rates of the power meters. This isthe first system for such type of street lightingcontrol in the country, applied for an entire city. Itis open for expansion, and other power substa-

Street Lighting in Gabrovo -an Energy Efficiency

Demonstration

PRACTICES

This section presents successfully implemented projects for energy efficiency improvement in street light-

ing systems in municipalities in the country and in Europe. The reports information is based on surveys

and data about projects implemented in member-municipalities of the Municipal Energy Efficiency

Network EcoEnergy, as well as examples from the Guide to the Main Issues in the Management of Public

Lighting by Local Authorities, published by the partners in the project Campaign for Local Energy

Efficiency Network (CLEEN)).

Project indicators:

Project costs total: BGN 1 073 386

Financing mode:

GEF grant, municipal budget, loan from NEPF, in-kind contribution of electricity company in Gabrovo

Annual savings: BGN 619 056, 5 729 MWh


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tions in smaller population centers of the area sur-rounding Gabrovo may be connected to it in thefuture.

The final annual savings resulting from the projectimplementation have reached 5 729 205 kW, to thevalue of BGN 619 056. As a result from the appliedenergy efficiency measures and saved electricity,reduction of GHG emissions to the amount of 9739 t CO2 equivalent/year will be achieved.

Besides reduction of the direct expenditure of themunicipality for

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