Lh / D ON / s i / 0 8r EFFECTIVENESS OF RURAL ELECTRIFICATION SCHEMES TO ENHANCE THE LIVING STANDARD OF RURAL COMMUNITIES A dissertation submitted to the Department of Electrical Engineering, University of Moratuwa in partial fulfillment of the requirements for the Degree of Master of Science by S.D.A. Padmasiri Supervised by 6 2 1 - 3 ^ 0 8 ' Department of Electrical Engineering University of Moratuwa, Sri Lanka £ I 2 O b January 2008 ^ University of Moratuwa 91206 Prof. Ranjit Perera .,„„„ U9PABV ~ UNIVERSITY OF MORATUWA, SRI LANKA MORATUWA 91206 DECLARATION The work submitted in this dissertation is the result of my own investigation, except where otherwise stated. It has not already been accepted for any degree, and is also not being concurrently submitted for any other degree. S.D.A. Padmasiri I endorse the declaration by the candidate. Prof, nary it Perera i ABSTRACT Government of Sri Lanka spends large amounts of money to implement Rural Electrification (RE) schemes with the support of concessionary loans from various funding agencies such as Asian Development Bank, Japanese Bank of International Corporation and Kuwait Fund. The expectation of the government is to develop rural areas by providing electricity to those areas and enhance the living standards of rural people. The aim of this study is to investigate the implemented RE schemes and to examine whether the desired targets have been achieved as planned in the initial stage and the reasons for failures if expected results have not been achieved, and to propose corrective actions to overcome those problems. Nine RE schemes were selected from Kalutara, Monaragala and Badulla districts which are implemented in the period of year 1998 to year 2000 by CEB under Project - RE 3 funded by Asian Development Bank for investigation. 1. Social and Economical development achieved by these schemes 2. Technical problems related to these schemes and reliability of electricity supply. The present situations of these schemes were investigated through a structured survey and compared the results with expectation of the planning stage. At the occasions of present results are deviated from the expected targets, corrective actions are proposed for implementation in existing RE schemes and also in future RE schemes. The development in social and economic benefits in the villages due to rural electrification schemes can be summarized as, ii Achievement on economic benefits, poverty alleviation, household benefits, education level, community benefits and incentive to build houses are found to be satisfactory. Improvements on employment opportunities, small industries, commercial and agricultural activities and health services are found to be not satisfactory. Migration of villagers to urban areas was reduced and no harmful environmental effects are observed. It is further revealed that reliability of electricity supply provided for rural villages are not satisfactory, Energy losses are considerably high, Load factor, Power factor and All-day efficiency of RE substations are at acceptable levels, Safety levels provided by the RE schemes are fairly low, The effectiveness of RE schemes were considerably reduced due to above technical reasons. ABC (Ariel Bundle Conductor) conductors are recommended in place of bare aluminium conductors to minimize reliability and safety problems. Small size transformers are recommended to reduce overall losses and cost of implementation. Electronic energy meters are recommended to reduce revenue losses. iii ACKNOWLEDGEMENT First I pay my sincere gratitude to Professor Ranjit Perera who encouraged and guided me to conduct this investigation and on perpetration of final dissertation. I also extend my sincere thanks to Dr. Tilak Siyabalapitiya who gave the project proposal and encouraged and guided me to conduct this investigation successfully and for valuable advice given for perpetration of final dissertation. I also thank to Dr. Narendra De Silva who gave the valuable instructions for research purposes and valuable advice given for perpetration of final dissertation. I would like to take this opportunity to extend my sincere thanks to Mr. D. Vithanage, Deputy General Manager (UVA-Province), Mr. J.M Saman Kumara (System Planning Engineer-UVA Province), Mr. H.P. Kumaradasa (Electrical Superintendent - Commercial)-UVA Province and his staff, Mr. W.M. Premarathna (Electrical Superintendent-Monaragala CSC) and his staff, Mr. D.P. De Silva (Electrical Superintendent-Projects,D4) and his staff, Mr. R.M. Thilakarathna (Electrical Superintendent - Agalawatta CSC) and his staff, Mr. M.M.A. Razmi (Electrical Engineer - Meter testing laboratory - D4) and his staff of Ceylon Electricity Board who gave their co-operation to conduct the investigation works successfully. It is a great pleasure to remember the kind co-operation extended by the colleagues in the post graduate programme, friends and specially my wife who helped me to continue the studies from start to end. iv List of tables Table number Description Table 1.0 Cost of RE Projects funded by various funding agencies. Table 1.1 Electrification levels in Sri Lanka as in mid 2006. Table 3.0 Details of the selected samples for the investigation. Table 4.1 Number of industries and commercial activities started after electrification. Table 4.2 Number of villagers who want to start industries, commercial activities and agricultural activities which require three phase electricity. Table 4.3 Usage of other electric items by RE consumers. Table 4.4 Phase loads of the feeders of RE substations. Table 4.5 Voltage variation along LT feeders. Table 4.6 Simulation and measured results of the feeder 2 of Batahenpitiya substation Table 4.7 Expected maximum demands of RE substations at the planning stage. Table 4.8 Initially expected and actual values of maximum demands of RE schemes. Table 4.9 Load factors of RE substations. Table 4.10 Power factors of RE schemes. Table 4.11 Energy losses of RE substations. Table 4.12 All-day efficiency of RE substations. Table 4.13 Number of breakdowns occurred from Jan 07 to Aug 07 in RE schemes of Agalawatta, Monaragala and Mahiyanganaya CEB consumer services centers. Table 5.1 Costs of LV lines per kilometer. Table 5.2 Power consumption of rural domestic consumers and assessment of maximum demand of RE substation. Table 5.3 Cost difference of 33kV / LV transformers used in RE schemes. V List of figures Figure number Description Figure 3.0 Geographical situation of selected samples. Figure 4.1 Monthly income levels of the families in electrified villages. Figure 4.2 Employment status of villagers. Figure 4.3 Usage of electric lamps. Figure 4.4 Penetration of televisions in RE schemes. Figure 4.5 Educational qualifications of rural villagers in electrified villages. Figure 4.6 Increment of electrified houses in RE schemes. Figure 4.7 Increment of voltage along the feeders of RE substations. Figure 4.8 Voltage variation at the end of LT line when increasing line resistance. Figure 4.9 Voltage variation at the end of LT line when increasing load. Figure 4.10 Voltage variation at the end of LT line when increasing (+ve) harmonic voltages Figure 4.11 Wave form of end voltage with (+ve) 3rd harmonic voltages. Figure 4.12 Voltage variation at the end of LT line when increasing (-ve) harmonic voltages Figure 4.13 Wave form of end voltage with (- ve) 3rd harmonic voltages. Figure 4.14 Basic model of three phase LT feeder. Figure 4.14.1 Model of LT feeder with equivalent loads. Figure 4.14.2 \TLAB simulink model of three phase LT feeder (without •monies). Figure 4.14.3 MATLAB simulink model of three phase LT feeder {with harmonics) Figure 4.15 Demand curve of Kurupita scheme Figure 4.16 Demand curve of Hobariyawa scheme Figure 4.17 Demand curve of Rideemaliyadda scheme vi CONTENTS Declaration Abstract Acknowledgement List of Tables List of Figures Contents Chapter 1- Introduction 1.1 Background 1.2 Present Electrification Level in Sri Lanka 1.3 The Expected Outcomes from RE schemes 1.3.1 Economic Benefits 1.3.2 Social Benefits 1.3.3 Social Indicators 1.3.4 Environmental Impacts 1.4 Motivation Chapter 2 - Problem statement 2.1 Identification of the Problem 2.2 Objectives of the Study 2.3 Importance of the Study Chapter 3 - Survey 3.1 Introduction 3.2 Preparation of questionnaire 3.3 Selection of samples 3.4 Description of the samples 3.5 Conduct of the survey Chapter 4 - Impacts of Rural Electrification 4.1 Economic benefits 4.1.1 Employment status of villagers 4.1.2 Development of industries and commercial activities 4.2 Social benefits 4.2.1 Household benefits 4.2.2 Improvement of education 4.2.3 Development of health facilities and community benefits 4.2.4 Environmental effects 4.2.5 Incentive to build houses Page No. i ii - iii iv v vi vii - viii 1 - 6 7 - 9 1 0 - 1 5 1 6 - 4 9 vii 4.3 Quality of electricity supply provided for rural villages 4.3.1 Voltage variation along RE feeders 4.3.1.1 Effects of change of line resistance 4.3.1.2 Effects of change of load 4.3.1.3 Effects of harmonics 4.3.2 Load development of RE schemes 4.3.2.1 Load pattern and demand curves of RE substations 4.3.2.2 Load factor of RE substations 4.3.3 Power factor of RE substation 4.4 Energy losses in RE schemes 4.4.1 Energy losses in RE schemes (beyond LT terminals of the transformer) 4.4.2 Energy losses and efficiency of the transformers in RE schemes 4.5 Reliability and safety of electricity supply in RE schemes Chapter 5 - Conclusion and Recommendation 5 0 - 5 9 5.1 Contribution of RE schemes towards the development Contribution of RE schemes: 5.1.1 to create employment opportunities 5.1.2 to promote small scale industries, commercial and agricultural activities 5.1.3 to promote household benefits 5.1.4 to the education of rural community 5.1.5 to promote health facilities 5.1.6 to promote community benefits 5.1.7 to promote housing 5.1.8 to environmental impacts 5.2 Technical problems and reliability of electricity supply 5.2.1 Energy losses in RE schemes 5.2.2 Load factor, Power factor and all-day efficiency of RE substations 5.2.3 Safety related matters of RE schemes 5.3 Recommendation 5.3.1 Use of Arial Bundle Conductors (ABC) instead of bare aluminum conductors 5.3.2 Use of 50kVA transformers instead of lOOkVA transformers 5.3.3 Use of electronic energy meters instead of normal electro-mechanical energy meters 5.3.4 Rehab i 1 itation of existing RE schemes References 60 Appendix I, II & III viii Chapter 1 Introduction 1.1. Background Governmen t of Sri Lanka spends a large amount of money , amount ing to several hundred million rupees every year to implement Rural Electr if ication (RE) schemes with concess ionary loans f rom various fund ing agenc ies such as Asian Deve lopment Bank (ADB), Japanese Bank of International Corporat ion (JBIC), Kuwai t Fund (KF) The expectat ion of the government of Sri Lanka is to develop rural areas through these projects and to enhance the rural living s tandards. T o implement these R E schemes, the government spends, taken f rom above fund ing agencies . Table 1.0 gives the funds spent to implement RE schemes in each year. Period of Implementation Name o f C E B Project Funded by Approximate Cost in Million USD 1983 - 1987 RE 1 A D B 11.3 1 9 9 2 - 1995 RE 2 A D B 74.3 1 9 9 5 - 1996 RE 2 (Extension) A D B 9.0 1 9 9 6 - 2 0 0 3 R E 3 A D B 55.0 2004 - 2006 R E 4 SI DA 23.5 2 0 0 1 - 2 0 0 3 RE 5 Kuwai t 14.4 2003 - 2006 RE 6 A D B 52.0 2004 - 2006 R E 7 China 24.0 Tab le 1.0 - Cost of RE Projects funded by various fund ing agencies . 1.2 Present Electrification Level in Sri Lanka The present overall electrification level of Sri Lanka is about 7 7 % (mid 2006). However , there are several districts whose electrif ication levels lie far below the national average. Table 1.1 gives the Provincial and District wise electrification levels as they were in mid 2006. Province Electrification. Level District Electrification. Level Central 7 9 % K a n d y 7 6 % Mata le 80% Nuwarae l iya 83% Nor th Central 6 6 % Anuradhapura 6 7 % Po lonnaruwa 6 5 % North Western 7 4 % Kurunegala 7 2 % Put ta lum 7 8 % West -Nor th 9 8 % G a m p a h a 9 8 % Eastern 5 8 % Am para 6 2 % Batt icaloa 5 0 % Tr incomalee 5 3 % Nor thern 3 8 % Vavuniya 6 3 % Kil inochchi 4 % J a f f n a 6 1 % M a n n a r 3 7 % Mula th ive 1% West -South 9 2 % C o l o m b o 9 7 % Kalutara 81% Southern 8 8 % Gal le 9 4 % Matara 9 0 % Hambanto ta 7 4 % Uva 5 8 % Badul la 6 7 % Monaraga la 5 0 % Saba ragamuwa 6 9 % Rathnapura 6 5 % Kegal la 7 4 % Sri Lanka (Overal l) 7 7 . 1 % Table 1.1- Electrification levels in Sri Lanka as in mid 2006. 1.3 The Expected Outcomes from RE schemes Rural electr if icat ion in Sri Lanka is general ly carried out in vi l lages with a certain level of deve lopment . Those vil lages en joy the basic needs such as water, Page 2 of 60 housing, t ransport , health, education, entrepreneurial support like extension services, credit facili t ies and markets . The addit ion of electricity to the existing infrastructure of these vil lages becomes an ef fec t ive catalyst in accelerating the growth in the vil lages and will improve the quali ty o f life in the villages. It is expected to develop facilities described below by vi l lage electrif ication. 1.3.1 Economic benefits N o n electrified vil lages in Sri Lanka use Kerosene oil for domest ic lighting. The first benef i t to be seen immediately after the electr if icat ion is the savings in the use of imported fuel . The rural electrification gives an impetus to the industries and it opens up many opportuni t ies for productivity growth, deve lopment of small scale industries and commerc ia l activities. It is expected to promote small industries such as Rice Mills, Rubber Mills, Coconut Fiber Mills, Saw Mills, Carpentry & Metal Workshops , Stone Crushers, Sugar Cane Crushers, Brick Making Machines , Garment Industries, Food Industries and Farms. Several of these industries may already exist in non-e lec t r i f ied vil lages using traditional techniques and power derived f rom Kerosene or Diesel. But with the availabil i ty o f electricity these industries will eventual ly convert to electricity thus increasing their output and leading to substantial savings in fuel and maintenance costs. In addit ion to the facilities made available to small scale industries, Med ium and Large scale industries can also benefit f rom the availabil i ty of substation and the spur med ium voltage lines. This gives a great contr ibution to the vil lage in providing employment and opening opportunit ies to sell ancillary services to the main industries. There are many more economic benefi ts which are of indirect nature. Households , commercia l establ ishments and workshops are able to engage in more productive hours, creation of employment , increased home garden cult ivation using domest ic water pumps, backyard farms and small cottage industries are few of the Page 3 of 60 engagements by which the electrif ication will contribute towards the e c o n o m y o f the village. 1.3.2 Social benefits The social benef i ts of the electrification of the vil lages are t remendous . The electr if icat ion on its own and integration with other facilities brings in a package of improvements in the quali ty of village life. These improvements in turn contribute towards the economic upl i f tment of the village. 1.3.2.1 Household benefits The immedia te benefi t to be seen on electrif ication is the domest ic lighting. Almos t all non-electr i f ied households use kerosene for lighting. M a n y houses use bot t le- lamps which are very inefficient and hazardous. Only a few houses use pressure type kerosene lamps. The introduction of the electric lamp makes the pattern of evening activities in the village home more comfor tab le and useful . Af ter some period of time, depending on the income of the household, other electric appl iances get introduced to the household. The items general ly used in electrified rural households are fans, TVs, refr igerators, domest ic water pumps, smooth ing irons, electric heaters kettles etc. With the availabil i ty o f electricity the life at home begins to improve in its quality. Extended hours will be available for whatever activity they wish to do. Villagers w h o spend long hours of work outside their homes will now be able to spend a few leisure hours at home reading news papers and watch ing television. 1.3.2.2 Improvement to education Children will improve their educational standard due to the convenience and extended hours of s tudy at home. In addition the school in the vil lage will also be able to improve its activities. Page 4 of 60 1.3.2.3 Improvement in health services The electricity will improve the quali ty of the service of rural hospi tals or health centers in the village. As an example, the ability to have a refr igerator in the vil lage health center to store vaccines will improve the child immunizat ion p rogrammes etc. 1.3.2.4 Community benefits While electrified households enjoy many direct benefi ts due to the electrif ication the whole village too reaps some direct and indirect benefits. When vil lages are electrif ied, the distribution is generally limited to the main central area of village. This is due to the heavy cost of electrification and even within the electrified area only some houses obtain connections. There are many ways by which every villager benef i ts f rom the electr if ication. They en joy more activities at the communi ty centers, and as the shops are kept open for longer hours with few street lamps at important places they are able to do shopping even dur ing night t ime. Repair shops, Carpentry shops etc. install new machines , welding plants and other equipment which would enable the villagers to get their needs within the village. Of ten the vil lage worker is unable to attend in day t ime rel igious activit ies due to his need to be at the work place. With efficient lighting being avai lable the temples , churches, kovils and mosques can arrange ceremonies in the evening hours of the day. Job opportuni t ies will also be created in the village due to improved and new commercia l and industrial activities. 1.3.2.5 Incentive to build Houses With the facility and opportunity being made avai lable in the village due to electrif ication, the migrat ion of the villagers to neighboring urbanized areas is reduced. The land prices will also be increased due to the demand . Page 5 of 60 1.3.3 Social Indicators General ly, Sri Lanka en joys the social indicators that are higher than those in other countr ies of similar economic status. In compar ison, it has a high literacy rate, high life expectancy at birth, low child mortali ty and a reasonably unproblemat ic birth rate. These ach ievements are due to the ef for ts that have been made in providing vital basic needs in the villages. The inclusion of electricity to these basic needs will eventual ly contr ibute greatly in raising the social indicators. 1.3.4 Environmental Impacts In order to erect medium voltage lines and low vol tage lines, trees and other obstacles must be cleared to provide the path dur ing construct ion and maintenance of electricity lines. The initial environmental inspection indicates that there is no signif icant environmenta l impact in the localities where the project is to be carried out. The studies on long term indirect environmental impact of RE projects [Ref 3] show that no adverse effects are recorded. The number of residents will increase, arresting the migrat ion to urban areas but there will be no boomtown effect . Med ium and large industries that may develop will pose environmental hazards but such industries will be adequately controlled by regulat ions in the country. 1.4 Motivation Although the Sri Lankan government is spending large amoun t s of money every year to implement RE schemes through the Ceylon Electricity Board, most o f RE schemes constructed by C E B are found not to be economica l ly viable. Usually, any type of business will not be sustained unless it is profi table. Similarly, in case of RE schemes, if those schemes cannot be maintained by C E B in a profi table manner , it will a lways be a loss to the C E B and ultimately creates bad e f fec t s to both C E B and to the rural deve lopment . As an Engineer in distribution sector of CEB, the author selected this topic to investigate the ef fec t iveness of RE schemes to enhance the living standard of rural communi t ies . Page 6 of 60 Chapter 2 Problem statement • 2.1. Identification of the Problem The expectat ion of the Sri Lankan government is to develop the country by upgrading rural vi l lages. Therefore , the government is a lways seeking to develop infrastructure facili t ies of rural villages and thereby enhance the living standards of rural communi ty and increase the productivity. To achieve this target the government is spending large amounts of money every year to provide electricity to the rural vil lages through the Ceylon Electricity Board. T h e construct ion and maintenance of these schemes are handled by CEB. General ly, f rom C E B ' s point of view, RE schemes are not profi table. However , when the social factors are taken into consideration, they contr ibute to make significant changes in soc io-economic development . Therefore , these schemes are essential to develop the living s tandards and to improve the product ivi ty o f rural communi t ies . Therefore , it is required to find solutions to the problems, I. H o w much do these schemes contribute to the rural deve lopment? II. H o w well does C E B handle construction and maintenance of these schemes to ensure the best profi tabil i ty? 2.2. Objectives of the Study The aim of this project is to investigate the implemented RE schemes and examine whether the desired targets have been achieved as planned in the initial stage. If the desired targets have not been achieved this study will examine the reasons for failures and propose correct ive actions to overcome those problems. During the investigation more attention is paid to the fol lowing, I. Social and Economic improvements achieved through the schemes on • Educat ion level • Employment level • Monthly Income • Household comfor t Page 7 of 60 - Small industries and commercia l es tabl ishments • Convers ion f rom uneconomical type of fuel into electrical energy - Heal th facilities II. Qual i ty of electricity supply provided for these schemes • Vol tage & power factor profile • Load curves & load factor • Energy losses • Reliabili ty and safety The details related to the present situation of a selected set of RE schemes were collected through a structured survey. Th i s study contains the fol lowing aspects as well , III. T o suggest corrective actions to be employed in fu ture RE schemes in order to achieve desired targets. For the success of this investigation, it was decided to select RE schemes f rom rural areas which are at least seven years old. All details used at the planning stage of these schemes were collected f rom relevant authorit ies. 2.3 Importance of the study Since the cheapest and reliable form of energy is the electricity, it can be used to develop rural infrastructure facilities and thereby develop rural communit ies . Therefore , rural electrif ication s c h e m e s ' a r e essential to develop rural areas. However , if these schemes cannot be constructed and maintained in a profi table manner , it will create a series of problems to the supply authori ty as well as to the rural communi t i e s and ultimately creates harmfu l e f fec ts to the development of the country. Therefore , it is essential to investigate the per formance of these schemes and find out the reasons for failures, if these schemes are found to be un-profi table . Page 8 of 60 This research will help to find feasible solutions for the above prob lems and the results obtained through this study will help to construct and maintain future RE schemes in a prof i table manner . Page 9 of 60 Chapter 3 Survey 3.1. Introduction For the success of this investigation, it is required to select RE schemes from rural areas which are at least seven years old after implementation. All details used at the planning stage should be collected from the relevant authorities and details related to the present condition of these schemes are collected through a structured survey. After collection of all related data, the originally expected targets should be compared with the present situation of the schemes. If a scheme failed to achieve the expected targets, suggestions to improve are to be made by analyzing the survey details. The information collection comprises three parts as given below: I. Collection of Technical, Social and Economic data used at the planning stage. • Collected from the initial investigation reports of the respective RE scheme. II. Social and Economic data at present • Collected from all consumers through the survey (see Appendix I) III. Technical data at present • Collected from field measurements and survey (see Appendix II) 3.2 Preparation of the questionnaire In order to gather sufficient ' information regarding the impact of electrification, a detailed questionnaire was prepared by obtaining the information from investigation report prepared for the RE Project 3 of CEB, questionnaire prepared for Social and Economic investigation for RE schemes in 1997 by the Distribution Planning Branch, CEB and through the experience gathered by the author working as an Engineer in Distribution Maintenance Branch in CEB. The questionnaire was divided into two sections to gather information of Social & Economic impacts (Questionnaire for RE scheme survey - section 01) and details related to the technical problems of RE schemes (Questionnaire for RE scheme survey - section 02). Page 10 of 60 Section - 01 included fifty five questions / information grouped into ten sub sections under the headings general details of the scheme, details of the house, educational & financial details, details of electricity supply, details of electricity usage, quality of electricity supply, street lighting, health services, environmental effects and details of vehicles. (Appendix I) Section - 02 included forty information grouped into seven sections under the headings general details of the scheme, development details of the scheme, technical details of medium voltage side and low voltage side, average load factor, average power factor, no-load loss of the transformer, and all-day efficiency of the transformer. (Appendix II) 3.3 Selection of Samples In order to get more accurate results from this study, it was decided to select matured RE schemes, at least seven years or more after implementation from various parts of the Island. Nine RE schemes funded by Asian Development Bank and implemented from 1996 to 2003 under the Project RE3 were selected from Kalutara, Badulla and Monaragala districts. The majority of rural people are farmers or labourers working on daily paid basis. They earn money from cultivating their lands or working as labourers in the same village or close to the village. It was noted that people in three districts have markedly different life styles. As the majority of these people are farmers, they must have enough water resources to cultivate their lands. They obtain water for the cultivation by different means, such as rain water or from irrigation schemes. This factor will create significant changes in their life styles. The people who use rainwater can't cultivate their lands equally throughout the year. Therefore, they cannot earn money uniformly throughout the year and their lives are not much comfortable. But, the people who use irrigation water to cultivate there lands can earn more money better distributed over the year and hence their lives become more comfortable. Page 11 of 60 3.4 Description of the Samples Table 3.0 gives the details of the selected samples for this investigation. All RE schemes selected are mature ones. (Project - RE 3, funded by ADB, 1996 - 2003). Geographical situation of the schemes are shown on the map in figure 3.0. SI No. District Electorate Name of the RE scheme and year of energized No. of Consumers in the RE scheme Total No. of Consumers in the sample Kelinkanda Stage II 1998 092 SI Kalutara Agalawatta Batahenpitiya 2000 181 575 Kurupita 1999 187 Horagoda 1999 115 S2 Badulla Maiyanganaya 47th Mile post, Arawatta 2000 343 675 Hobariyawa 1999 332 Monaragala Punsisigama 1999 278 S3 Monaragala Higurukaduwa 1998 217 636 Bibile 5th Mile post, Rideemaliyadda 2000 141 Total No. of Consumers 1886 Table 3.0 - Details of the selected samples for the investigation. Page 12 of 60 il Figure 3.0 - Geographical situation of selected samples. Page 13 of 60 3.5 Conduct of the survey The survey was conducted by the author with the help of experienced Electrical Superintendents in Kalutara, Badulla and Monaragala CEB administrative areas. Each house was visited by a team consisting of two or more members who have experience in electricity distribution sector and technically qualified up to National Diploma in Technology level. The questions were explained and answers were noted down by the team members. It was observed that the answers given to the same question by two members in same family were different. The answer can also depend on how the question is posed and how much background information is given. Therefore, care was taken to minimize possible discrepancies due to such effects through the continuous consultation with the team members. For the technical part of this survey, metering equipment were installed to the substations by CEB staff with the supervision of the author and accuracy of the data recorded in the meters were checked by the CEB staff of meter testing laboratory Region -04. Load readings of substations at night time were taken by the author with the help of CEB staff of relevant CEB area. The villagers in all areas gave their fullest co-operation to the teams carried out the survey and especially low income families have been very open in answering the questions. Collecting consumers' details by the survey team at Punsisigama, Monaragala. Page 14 of 60 Collecting consumers' details by the survey team at Horagoda, Baduraliya, Agalawatta. Collecting consumers' details by the survey team at Kelinkanda, Agalawatta. Page 15 of 60 Chapter 4 Impacts of Rural Electrification 4.1 Economic benefits After electrification of rural villages, imported fuel usage for domestic lighting has greatly been reduced and only very small quantities of Kerosene are still being used for emergency lighting purposes during electricity failures. Thus, the immediate economic benefit reaped by the villagers is the saving on imported fuel usage for domestic lighting. Electricity alone is not enough to develop these villages and the quality of other infrastructure facilities like roads, transport, educational and medical facilities are also vital. Considerable economic development in rural villages has been achieved after provision of electricity in districts already having better infrastructure facilities. Monthly income of family % n um be r o f c on su m er s -^ lo w ^ u if fi N iC D c o a D O O O O O O O O O O 6 5.6% m M % 6 2 1 2 % 16.4% n n 3.8 % 7 6 4% 8.4% 10-8% . n n n .1 % 6 10.1% g 0% 1 1 - 2 % n n n 3.0 % 12.1% 7 ? % n n „ o £ o 5 o 05 « CQ tfl 1 o ° O o O O o o > 9 H o O O S tN -5 CM «> X < rv OC CE Q- (alutara distric o c ^ o 01 z: E o O t S § 5 o o> CD » I o O o o R o S m cm "> X a_ a. 3adulla o 0) o > s o o XI CM < in en distric o c O oi Z E o O s § 5 o o 10 CO W1 sr Mc 1 o o g O R o ° in CM >narage 01 A bo ve w R s. 20 00 0 o c « o 0> z E o Q ict 5 8 6 o a m CO «1 Tot 1 o O O ° R o ° 55 cm V) » cc ct al for a w A bo ve 3 R s. 20 00 0 • ~o o C W o | o o es Figure 4.1- Monthly income levels of the families in electrified villages. A good measurement to determine the economic development is the family income. The figure 4.1 shows the present monthly income levels of the families in electrified villages in Kalutara, Badulla and Monaragala districts investigated under this study. The income levels of families in these villages were divided into three categories for the convenience of analysis. Monthly Income level of the families is below Rs. 5,000.00 per month has been considered as low income level. Similarly, monthly income level of the families between Rs. 5,000.00 and Rs. 20,000.00 has Page 16 of 60 been considered as moderate income level and income over Rs. 20,000.00 per month has been considered as good income level. Here non-domestic consumers mean consumers like schools, community halls, government offices, hospitals, who has obviously no family income. A significant increase in number of moderate income level families can be seen in each district after electrification. The figure of moderate income level in Kalutara district is 67.1%. This figure in Badulla and Monaragala districts are 68.8% and 71.1% respectively. The overall percentage of the moderate income level families is 69.0%. When comparing percentage of good income level families with the other districts, in Kalutara district its value is 21.2% and Badulla and Monaragala are 6.4% and 10.1% respectively. The reason for this change is the better availability of other infrastructure facilities like transport, market facilities and business opportunities in Kalutara district. The overall percentage of the moderate income level families is 12.1%. When considering low income families, in Kalutara district it shows a lower value of 5.6% than in the other two districts. This value in Badulla and Monaragala districts are 16.4% and 10.8% respectively. One of the reasons for this situation is the poor educational background of the adults. Lack of education causes poverty. Children of poor families cannot obtain a good education unless good educational facilities freely available in the village, because, their parents are not in a position to spend enough money for education due to their poor income. It is observed during this study that a large number of children in poor families have very low educational levels (124 children of 232 families). Sometimes it was even lower than grade five standard and most of them are labourers. When considering overall values, the above results indicate that the addition of electricity to the existing infrastructure will accelerate the development of rural villages. The ratio between (Low: Moderate: Good) income levels is (1.0: 6.2: 1.1). Therefore poverty has been alleviated significantly after electrification. The study revealed that the majority of good income level family members are well educated people employed as school teachers, police officers, officers in the military forces, Page 17 of 60 businessmen etc. However, many people in this category are working far from their village. 4.1.1 Employment status of villagers The majority of rural people are self employed as their education is insufficient obtain employment in the government or private sector. Those who own their own land engage as farmers. Considerable percentages of rural people who do not have lands for cultivation are working as labourers within the same village or in the neighboring villages. Another section of rural people find employment in the private sector and they work in the close proximity to the village. A smaller group with good educational background of work in the government sector. The majority of them are working away from their own village. 60.0% £ 50.0% CD 40.0% E u ^ 30.0% 20.0% CD CO 2 0 10.0% 0) JZ o 0.0% Employment status 53.1% 42.8% 21.1% 10.2% 25.9% 10.6% 7.8% 55.1 28.5% 21.1% t l i 50.7% 13.3% 12.71 14.0' 22.6°/ S1- Kalu B Govt S2 - Badulla B Private S3 - Monaragala • Self Total • Other Figure 4.2 - Employment status of villagers. Above figures confirm that the majority of rural people are self employed as fanners in all districts with a sample average of 50.7%. The second biggest group called 'Other' is working as labours on daily paid basis with a sample average of 22.6%. The third biggest group is the group of government servants with an overall value of 14.0%. Majority of these government servants are working in the government security forces. The remaining 12.7% work in private sector. Many of them work as Page 18 of 60 LIBRARY ^ UNIVERSITY j^Mp^ATUWA, SRI LANKA MQRATUWA labours, drivers, or security guards. Though a small increase in employment opportunities has been observed that cannot be directly attributed to electrification. 4.1.2 Development of industries and commercial activities Table 4.1 gives the numbers of industries and commercial activities developed due to RE schemes. (Total number of RE consumers - 1886) Sample SI - Kalutara S2 - Badulla S3 - Monaragala Total % of the total consumers (1886) Small industries 03 14 06 23 1.2% Small commercial 18 35 43 96 5.1% Table 4.1- Number of industries and commercial activities started after electrification. The above numbers show that there is no significant development in small scale industries and commercial activities due to electrification of rural villages as expected at the beginning. It is observed that a very little number of industries like rice mills, grinding mills, welding shops, saw mills were created. Small commercial activities like retail shops, tea shops at village junctions, small retail shops in a part of the house, concrete workshops, barber saloons, small garment workshops within the household have been created in the schemes. Cottage industries or agricultural activities using electricity were rare. 91206 Page 19 of 60 % to the total RE consumers S2 - Badulla Sample No Kalutara Monaragala Small industries Small commercial Small agricultural Table 4.2 - Number of villagers who want to start industries, commercial activities and agricultural activities which require three phase electricity. The percentage of small scale industries that were created during the last seven years is a mere 1.2%. But the people who have ability to start industries like rice mills, metal work shops, saw mills are awaiting three phase electricity supply to start their industries. The table 4.2 shows that the percentage of this category is 1.3% which is even slightly higher than the industries created up to date from the beginning. Thus the non-availability of three phase electricity imposes limitations. Although three phase electricity lines are available in the vicinity, industrialist cannot obtain three phase electricity supply to start industries due to various technical problems. The distance to the transformer from the industrial premises is the main problem. Supply of three phase electricity to these premises was considerably restricted by the CEB rules and A youth repairs electronic equipment at home as a self employment in Horagod Page 20 of 60 regulations. Frequent failures in electricity supply are also having a negative impact on the industrial development. 4.2 Social benefits After electrification, large number of houses gained adequate lighting. This is the immediate benefit they received from electricity. Majority of rural people are farmers and they are working in their paddy fields or gardens until dusk. Rural women are also working in their paddy fields or gardens with their husbands but they tend to return home a little earlier to light night lamps and prepare meals. But, after electrification rural women were able to manage their evening works at their homes more easily due to availability of easy lighting extending their working times. It is observed during the investigation that some fanners work even during night time after electrification. 4.2.1 Household benefits Generally, after electrification every house owner purchases electrical appliances according to their requirements. Time duration for this purchasing will depend on the income level of the family. Figure 4.3 shows the usage of electric lamps. Figure shows that they widely use inefficient incandescent lamps. The usage of fluorescent lamps and compact fluorescent lamps for domestic lighting has been limited mainly due to their high initial cost. 2000 1800 1600 & 1400 I 1200 ° 1000 CD | 800 | 600 400 200 0 532 I86-144 • s n Use of electric lamps 1798 647 619 130140 131 157 447441 S1-Kalutara S2-Badu l la S3 - Monaragala • IL E FL Total • CFL Figure 4.3 - Usage of electric lamps. Page 21 of 60 Televisions are very popular in rural homes as well. Usage and quality of television increased as a result of electrification and as a result the villagers are better informed. Mainly, they use this media for the family entertainment like watching tele- dramas and films. A small number of families use televisions for the educational purposes of their children. Televisions greatly help them to reduce isolation effect and enhance their satisfaction to continue to live in their villages. 100.0% | 90.0% J ® 80.0% | 70.0% | 60.0% j o 50.0% : S. 40.0% ' CO Use of televisions 86.4% CD O i— CD Q. 30.0% 20.0% 10.0% 0.0% 79.1% n m n s ; i • • f l P i SMWsjsi l i l l l * l l l i i l i sjaippp 83.8% Kalutara(575) Badulla(675) Monaragala(636) Sample (No. of consumers) Total (1886) Figure 4.4 - Penetration of televisions in RE schemes. Figure 4.4 shows the penetration of televisions in each sample. As an overall figure, 83.8% of families use televisions. The information in Figure 4.4 indicates that this media is almost equally popular among all of them. Table 4.3 gives the other electrical appliances used. It is observed that the RE consumers use many electrical appliances in their houses. This is an evidence for their improved family income and comfort at home. 77.8% of RE consumers use radios/cassettes. 72.7% use electric irons and 18.1% use refrigerators. 16.7% use domestic water pumps and 33.0% use at least one electric fan. 16.5% use immersion heaters / kettles for heating water in their homes, 6.4% use rice cookers and 7.7% use electric blenders. Only a few RE consumers use electric ovens for baking and grilling. The use of computers is still at a very low level Page 22 of 60 Use of other electrical appliances Total Consumers Rice cookers Heaters / Kettles Refrigerators Electric Irons Wash, machines Electric fans Radios/cassettes Electric ovens Computers of 0.3%. However, it is clear that there is a considerable increment of household benefits created through electrification. Table 4.3 - Usage of other electrical appliances by RE consumers. 18.1% 72.7% 4.7% 33.0% Pom, w/pumps Blenders 4.2.2 Improvement of education 50.0% 45.0% 40.0% 35.0% 30.0% 25.0% 20.0% 15.0% - 10.0% 5.0% 0.0% Figure Kalutara Badulla . Monaragala Total 0 5 pass • 8 pass n u p t o O / L • u p t o A / L a Degree 4.5 - Educational qualifications of rural villagers in electrified villages. Improiement of education Figure 4.5 illustrates the education level in rural villagers. When considering total figures, only 1.0% of rural villagers were obtained education level up to degree level. 13.0%, 43.4% and 25.6% of young villagers were educated up to A/L, O/L, and grade eight respectively. All villagers in these categories had finished their school education few years after electrification. About 16.9% were obtained education up to grade five. But the majority of this category is elder persons in the villages. They had finished their school education before the electrification of these villages. Very little number of young persons in this category had finished their school education due to low income level of their families. The above figures indicate that they have achieved considerable development in their education level after electrification. Although, provision of electricity creates positive impacts on education, lack of other educational facilities like, good schools and adequate numbers of teachers in rural schools have negative effects. Extremely low percentage (1.0%) was able to obtain higher education to the level of a university degree. However, it is clear from the above figures that the literacy level has increased significantly in rural villages as a result of electrification. 4.2.3 Development of health facilities and community benefits. Health facilities: It is observed during the investigation, sanitary facilities of many households have improved. In Kurupita, Punsisigama and Higurukaduwa schemes villagers have launched mini water supply projects to obtain drinking water using electricity without any intervention of the government. About 95.6% houses have water seal type toilet facilities. Health centers or private medical dispensaries have not been created up to date within any other villages except in Higurukaduwa. In Higurukaduwa scheme a rural hospital have been opened by the government. Other than this dispensary no other improvements are observed in the villages apart from improved sanitary facilities. Community benefits: It is observed during the investigation that the street lighting in these villages is very poor. Although, street lamps have been fixed at several locations, more than 85% of them are not in operating condition. The main reasons for this are the poor standard of street lamps and lack of proper maintenance. However, after electrification, working time of the villagers has extended significantly. People of some villages have agreed to shift their society meetings such as that of funeral society to night time. As the adequate lighting facilities are available, they were able to conduct the social activities even during night time. By doing this, their working time has extended and they are able to work longer in their paddy fields or gardens helping to increase the productivity. Page 24 of 60 Further, they were able to engage in religious activities in village temple during night time. This is very common to all rural villages. By arranging religious activities at night time, a new opportunity has been created for people who are otherwise unable to participate due to their commitments at the work places. A considerable improvement on community benefits have been created by the electrification. 4.2.4 Environmental effects Though the trees are to be removed from time to time for the construction and maintenance of LT lines, no further environmental damages have been created locally in these villages up to date. 4.2.5 Incentive to build houses Figure 4.6 gives the number of houses electrified up to date from the beginning of electrification. These figures indicate the considerable increment of number of houses in each village after electrification. The average time period is about seven years. This tendency has been occurred after electrification of these villages. The cost of living is significantly low in rural villages than the urban areas. Generally, their needs are very simple in nature and they can obtain those needs from their surrounding. As a result of electrification, these villages were become more comfortable and they have decided to stay further at the same villages. Therefore it is clear from the results of the investigation; migration of rural people to urban areas has been considerably reduced after electrification of these villages. I n c e r m e n t of e lec t r i f i ed h o u s e s Figure 4.6 - Increment of electrified houses in RE schemes. Page 25 of 60 4.3 Quality of electricity supply provided for rural villages Electricity supply provided to the rural villages cannot use efficiently due to various technical problems. As an example, consumers cannot use electricity to their day to day work efficiently if low voltage conditions occur frequently. The objective of the Ceylon Electricity Board is to provide continuous, adequate and reliable electricity supply to their consumers. In this section the technical matters of the rural electrification schemes are investigated and positive and negative effects created by these schemes to the development of rural villages are discussed. 4.3.1 Voltage variation along RE feeders According to the regulations, stipulated value of the voltage variation should be within the limit ± 6%. At the commissioning of the schemes voltage variations might have been within the stipulated limits. But with the continued operation of the schemes, voltage drop has increased gradually and exceeded the lower limit. Table 4.4 gives the loading of LT feeders investigated in this study. All readings were taken within the period 7.30pm - 9.30pm to determine the worst case voltage drop of the feeders. The figures of the table 4.4 indicate that all feeders connected to each substation are in an unbalanced condition and some of them are severely unbalanced. Loading of feeders of RE schemes Sample Scheme Feeder 1 Feeder 2 Feeder 3 Feeder 4 R Y B N R Y B N R Y B N R Y B N Kelinkanda 6 .5 10 * 8 14 20 * 2 3 7 * * * * * S1 Batahenpitiya 2 17 25 * 10 24 53 * 6 25 38 * * * * * Kurupita 28 46 24 * 25 40 21 * * * * * * * * * Horagoda 10 5 18 8 32 15 16 12 32 20 12 18 * * * * S2 Arawatta 21 11 1 18 52 43 44 12 10 7 5 6 21 32 13 21 Hobariyawa 16 24 70 47 40 34 50 50 41 44 23 27 * * - * Punsisigama 12 30 13 13 33 32 31 11 40 70 39 30 * * * * S3 Higurukaduwa 10 18 24 * 7 12 23 * 18 31 15 * * * * « Rideemaliyadda 32 20 30 11 12 43 11 31 16 9 10 7 » * * * N.B. unit of load current is Ampere. Table 4.4 - Phase loads of the feeders of RE substations. Page 26 of 60 Practically, it is not possible to obtain an exact balance condition of LT feeders. But it is very essential to balance them approximately to reduce energy losses, breakdowns and other harmful effects to the consumer equipment. Due to severe unbalance conditions unwanted thermal stresses are created in contact points of LT switchgear leading to reductions in life time of the switchgear. Supply failures may also occur due to this reason. This situation can be seen in many RE schemes. Voltage variation along the heavily loaded feeders of RE substations 241 -n c 241) W 2 3 9 238 T : j 0.6 0 .7 0.8 0.9 1 1.1 1.2 1.3 1.4 1.5 Resistance (Ohm) Figure 4.8 - Voltage variation at the end of LT line when increasing line resistance. Bad jumpers increase the resistance of LT lines. Page 29 of 60 Under the condition of load and harmonics is constant, end voltage of a LT line will reduce with the increment of line resistance. Bad jumpers of these lines will increase line resistance and voltage drop. 4.3.1.2 Effects of change of load. Line load Vs End voltage (R & Vh constant) 244 __ 242 - C 240 ojj 238 (3 ~ 236 o > 234 -a c 232 W 230 228 900 1400 1900 2400 2900 Load (W) Figure 4.9 - Voltage variation at the end of LT line when increasing load. Under the condition of line resistance and harmonics is constant, end voltage of a LT line will reduce with the increment of load current. 4.3.1.3 Effects of harmonics. (+ ve) 3rd Harmonic voltages Vs End voltage 260 235 -I , t — r- , — ;—, , i 0 20 40 60 80 100 120 140 Harmonic wl tage (V) Figure 4.10 - Voltage variation at the end of LT line when increasing (+ve) harmonic voltages. Page 30 of 60 is 7 S si; i • : : ' 'iiiisi : s Sg; i S Figure 4.11 - Wave form of end voltage with (+ve) 3rd harmonic voltages. ( - ve) 3rd Harmonic voltages Vs End voltage o 00 o > -a c W 260 255 250 245 240 235 -140 -120 -100 -80 -60 Harmonic voltage (V) -40 - 2 0 Figure 4.12 - Voltage variation at the end of LT line when increasing (-ve) harmonic voltages Figure 4 . 1 3 - Wave form of end voltage with (- ve) 3rd harmonic voltages. Under the condition of line resistance and load is constant, end voltage of LT line will increase with the increment of harmonic voltages. Figures 4.10 & 4.12 show the variation of end voltage in the presence of +ve 3rd harmonic voltages and -ve 3rd Page 31 of 60 harmonic voltages respectively. With the presence of any harmonic voltage can create this situation in LT lines. Wave forms of end voltage corresponding to the +ve 3rd harmonic voltages and -ve 3rd harmonic voltages are shown in Figure 4.11 & Figure 4.13 respectively. Harmonics can be generated by the equipment connected to the power lines like welding plants, televisions, compact fluorescent lamps, capacitors. Harmonic voltages can also be generated in the substation transformer due to the change of magnetic properties of the transformer core. However, transformer generated harmonics influence the voltages on all three phases equally. As this is not the case in the schemes under consideration it is concluded that the harmonics are generated by the loads. A basic model of three phase LT feeder built using MATLAB Sim Power System to investigate the voltage variations in RE schemes is shown in Figure 4.14. At the substation end, we use three star connected windings to represent the low voltage side of the transformer and this star point is directly earthed at the substation end. The line conductors are represented by series resistances as shown in the figure 4.14 since inductive and capacitive effects are negligibly small in low voltage lines. •-AMr— —TfF1-" -A/W- l ine resistance2 — A M r — l ine resistance3 •-AMr* Sing le-Phase Load 1 Three-Phase Load S ing le Phase Load 2 S ing le Phase Load 3 T J_ Figure 4.14 - Basic model of three phase LT feeder. Page 32 of 60 Although, the actual loads are connected in parallel, we can use the Thevenin's equivalent in series with the line resistance to represent all loads connected between phase and neutral conductors as shown in the figure 4.14.1. Finally, the star point of the individual loads should be connected to the ground through a series resistance to represent the neutral conductor of the feeder and complete the circuit. Transformer of villagers are educated up to or above O/L) Improvement of health services - Not satisfactory (Except elimination of traditional oil lamps, no significant development in health facilities due to electrification) Improvement of community benefits - Satisfactory Incentive to build houses - Satisfactory (No of houses have been increased by 232.2 %> than the beginning of scheme) Environmental impacts - No harmful effect Page 52 of 60 5.2 Technical problems and reliability of electricity supply The quality of electricity supply provided for rural villages is not satisfactory. Many numbers of feeders of RE substations are heavily unbalanced and voltage drop exceeds the stipulated value. Numbers of breakdowns in RE schemes are very high and the reliability of electricity supply is in very poor condition. Majority of breakdowns occur due to way leaves. Maintenance of lines and substations are not satisfactory. Maintenance cost of these schemes has been greatly responsible for this situation. As the maintenance cost is considerably high, supply authority is not in a position to carryout maintenance work of lines and substations properly and therefore breakdowns occur more frequently. 5.2.1 Energy losses in RE schemes Energy losses of these schemes are considerably high. Illicit tapping and tempering of electricity meters at consumers' premises are contributing to increase the average losses. As bare conductors have been used for construction of these schemes illicit tapping is difficult to be eliminate. Poor maintenance of consumers' energy meters increase revenue losses Page 53 of 60 5.2.2 Load factor, Power factor and all - day efficiency of RE substations The maximum daily load factors of RE substations are less than 53% and over capacity transformers have been used at many schemes. This situation increases cost of implementation at the beginning of these schemes and the cost of maintenance in case of replacement of transformer. Due to defects of substation earthing lifetime of the transformers have considerably reduced. Average power factor and all-day efficiency are at acceptable levels. 5.2.3 Safety related matters of RE schemes Safety level provided by the RE schemes is fairly low. Accidents occur due to falling live conductors on to the ground under bad weather conditions. Probability of damages to the consumer equipment in bad weather conditions is high. The effectiveness of RE schemes has been considerably reduced due to above reasons. If this situation is not removed immediately effectiveness of RE schemes will be reduced further leading to non- achievement of desired results. 5.3 Recommendation In order to overcome these problems and to increase the effectiveness of RE schemes some recommendations are given below: 5.3.1 Use of Arial Bundle Conductors (ABC) instead of Bare Aluminium Conductors For LV lines in RE schemes, ABC conductors are recommended in place of bare Aluminium conductors. Use of ABC conductors provides following benefits: (a). It will greatly reduce the number of LT breakdowns that occur due to way leaves. Reducing the number of breakdowns, maintenance costs reduced to a bearable limit and reliability of electricity supply increases considerably and improving the consumers' satisfaction about electricity supply. Page 54 of 60 (b). Illicit tapping of electricity lines will not be easy and can be avoided satisfactorily and reduce the revenue losses. (c). The events of breaking poles and conductors due to fallen trees will be greatly reduced. This will avoid major breakdowns and reduce the cost of maintenance. It also helps to increase the safety of both personnel and equipment. The main barriers to convert LV lines from bare conductors to ABC conductors are the cost of lines and lifetime of ABC conductors. Table 5.1 gives the cost difference between bare aluminium conductors and ABC conductors per kilometer. The cost is increased by 22.6% (Rs. 160,000.00) per kilometer, for ABC conductors. When comparing both bare aluminum conductors and ABC conductors, the cost difference is not much but the life time of bare conductors is greater than that of ABC conductors. However, the additional cost can be justified by the benefits achieved by using ABC. The recommended maximum length of a feeder can be kept at constant level of 1.8 km for ABC conductors too. The recommended size of ABC conductors is (3x70+50mm2) for 3 phase 4 wire LV lines. New LV line construction cost per kilometer. (A) (B) Difference o f . Costs (A-B) Remarks Cost per km when use FLY conductor (7/3,40mm) 3ph,4wire (Rs) Cost per km when use ABC conductor (3x70+50mm2) 3ph,4wire (Rs) 708,000.00 868,000.00 160,000.00 Cost of line is increased by 22.6% Table 5.1 - Costs of LV lines per kilometer. [Ref 9] Page 55 of 60 5.3.2 Use of 50 kVA transformers instead of 100 kVA transformers Investigation results show that the maximum demands of many RE schemes are below 50kVA. The range of average load factors of all these schemes lies between 25% - 55%. [Although, some of these substations, the maximum demand have been increased up to 84 kVA for a short duration (about three hours per day) when considering voltage drop, line length and number of consumers of those substations augmentation is required]. If 50kVA transformers are used they can be loaded up to 125% (62.5 kVA) for a short duration (about three hours per day) without any harmful effect. Therefore, considerable saving in cost of implementation and cost of maintenance can be achieved by using 50kVA transformers instead of 100 kVA transformers under the following recommendations. I. Total distance of LV line from the substation to end of the line should not be increased from current value of 1.8 km. II. Number of consumers per substation should not exceed 160. Table 5.2 shows the power consumption of rural domestic consumers. The average power consumption of large, medium and small houses is 1.0 kW, 0.45 kW and 0.2 kW respectively. Power consum jtion of rural domestic consumers Type of house Avg. power consumption (kW) % No. of houses Total power (kW) Avg. Pf Total demand (kVA) Avg. current (A) Large house 1.0 6% 10.2 0.88 11.6 5.2 Medium house 0.45 32% 23.0 0.88 26.1 2.3 Small house 0.22 62% 21.8 0.88 24.7 1.1 Total No. of houses per sub 160 Allowable max. demand of sub (kVA) 62.5 Assessec (kV demand rA) 62.5 Page 56 of 60 \ % Table 5.2 - Power consumption of rural domestic consumers and assessment of maximum demand of RE substation. By using 50 kVA transformers for the substations the total construction can be reduced further. Table 5.3 gives the amount of saving.[Ref 9] Cost for 33kV/LT, lOOkVA t/f Rs. 558,560.00 Cost for 33kV/LT, 50kVA t/f Rs. 400,000.00 Saving Rs. 158560.00 Table 5.3 - Cost difference of 33kV / LV transformers used in RE schemes. 5.3.3 Use of Electronic energy meters instead of normal electro-mechanical energy meters By using electronic energy meters instead of normal electro-mechanical energy meters losses created by tempering of energy meters can be reduced. Although electro-mechanical energy meters record the total electricity consumption, it does not record the past consumption in individual time periods (say one month period). As the domestic electricity tariff consists of block rates, the blocks with higher rates can be avoided by adding excess units consumed by the consumer to the following month with the help of meter readers. As an example, suppose a consumer has used 100 units within a 30days period, according to the domestic tariff these 100 units will be distributed as, [Ref 10] Block Units Rate (Rs) Consumption Amount(Rs) 1st Block 1 - 3 0 3.00 30 90.00 2nd Block 3 0 - 6 0 3.70 30 111.00 3rd Block 6 0 - 9 0 4.10 30 123.00 4th Block 9 0 - 1 8 0 10.60 10 106.00 Total 100 430.00 Page 57 of 60 Since, there is no permanent record in the electro-mechanical meters, consumer can avoid last 10 units in the 4th block and it can be added to the following month with the help of meter reader and his monthly electricity bill can be reduced by Rs. 106.00. But, as the electronic meters record the past consumption with date and time, consumers cannot continue illegal practices. As there is no moving parts in electronic meters tempering is very difficult. Even the tempering affects will be recorded in the meter and such records can be used as evidence to take legal action against them. Electronic meters can be used to take survey of consumer load parameters like kVA, kWh, Voltage, Current and number of power failures within a particular period of time. These details will help in planning and finding solutions to the problems related to the electricity supply. Remote meter reading facilities can be added to the domestic programmable energy meters and can be used to take the meter readings form a remote place through a communication channel. The main disadvantage of electronic meters is the cost of meters. The cost of normal electro-mechanical meter is about Rs. 1200.00, but the cost of programmable single phase electronic meter is nearly four times the cost of normal electro- mechanical meter. But with the development of software industry, these meters will be cheaper than the normal electro-mechanical meters in near future and will be more popular in electricity distribution sector. 5.3.4 Rehabilitation of existing RE schemes As a temporary and immediate solution to reduce breakdowns, way leaves should be cleared to a satisfactory level in all LV and HV lines and loads of LV feeders should be balanced as far as possible. A considerable saving of maintenance cost and reduction in energy losses can be obtained by replacing aluminium conductors of spur lines by ABC conductors of Page 58 of 60 existing RE schemes. This should be done by studying individual RE schemes and identifying worst case problems. Initially, bare conductors of spur lines in bad condition and most liable to frequent breakdowns should be replaced by ABC conductors. This process to be continued step by step until breakdowns are reduced to a satisfactory level. Substation maintenance programme should also be activated simultaneously with the above line rehabilitation programme and should carryout continuously. A decision must be taken from the higher authority, not to extend spur lines of RE schemes by using bare aluminium conductors further in these schemes. Page 59 of 60 References [1] Ceylon Electricity Board - Rural Electrification Unit, "Project Inception Report-2004 - Rural Electrification and Expansion" CEB, 2004 [2] Ceylon Electricity Board - Rural Electrification Unit, "Rural Electrification Project 8", CEB, May 2007 [3] Ceylon Electricity Board - Distribution Development Branch, "Rural Electrification Project 3" CEB, July 1995 [4] HYR Perera - Department of Electrical Engineering - University of Moratuwa, "Impacts of Electrification on Quality of Rural Life" - Technical paper, HYR Perera, 1996, p p l O - 17 [5] Ceylon Electricity Board - Distribution Planning Branch, "Socio- Economic Investigation for Rural areas" - Format for investigation, Rural Electrification Uni t -CEB, 1997, p p 0 1 - l l [6] Ceylon Electricity Board - Distribution Planning Branch, "Investigation reports of RE schemes - Kelinkanda stage II, Batahenpitiya, Kurupita, Horagoda, Punsisigama, Higurukaduwa, 8th Mile Post, Riddemaliyadda, Arawatta and Hobariyawa", Rural Electrification unit - CEB, December 1996 [7] B.L. Theraja & A.K. Theraja, "A Text Book of Electrical Technology - twenty second edition", S.Chand & Company Ltd-Ram Nagar - New Delhi, 1998, pp 960-972 [8] Ceylon Electricity Board, "Breakdown reports of Agalawatta, Monaragala and Maiyanganaya CSCs from January 2007 to August 2007" CEB, 2007 [9] Ceylon Electricity Board - Distribution Planning Branch, "Standard construction costs - 2007", Chairman Distribution Co-coordinating Committee CEB, January 2007, [10] Democratic Socialist Republic of Sri Lanka, "Gazette Notification (Extraordinary) - No. 1429/39 - Friday January 27 2006", Government of Sri Lanka, January 27 2006, pp 1A Page 60 of 60 Section (01). Questionnaire for RE scheme Survey. Appendix ( l ) Scheme: | j Date of Survey : [ 2.00 Details of the House 2 .10 2.20 2.30 2.40 2.50 2.60 2.70 2.80 2.90 2 .10 2.11 2.12 House No: Nature of the house : Single house/Two storey building/Temporary house/ Line room/ still under construction. Floor area : Sq. ft. Roof: Tile / Asbestos / Gl sheets / Other. Walls : Bricks / Cement block bricks / Clay / Timber plank / Other. Floor: Cement / Tile / Clay No. of rooms : Ownership : Own / Rent / Other Water supply : Own well / Common well / Common pipe / Irrigation cannel /Other. Toilet facility Water seal type / Other. Current market value of land : |Rs. Per perch. Did the land value increased after electrification : |Yes / No. 3.00 Educational and Financial details. 3.10 No. of members in the family: 3.20 Education level of the family members and employment status. Distance to the work place 5 pass 8 pass O/L A/L Degree Employment Village Town Other Father Mother Children 1 2 3 4 5 3.30 3.40 3.50 Other sources of income: (If any) Approximate monthly expenditure: No. of school going children: Rs. 4.00 4.10 4.20 4.30 4.40 4.50 4.60 Details of Electricity supply. Year & month of electricity supply taken : Tariff: Nature of the service connection : single phase / three phase. Length of the service wire : meters Distance to the transformer: meters No. of wired lamp points : Nos. No. of wired 5A plug points : Nos. No. of wired 15A points : Nos. Average electricity consumption over last 12 months: Units/month Domestic Commercial Industrial 5.00 5.10 5.20 5.30 Details of Electricity usage. Lighting purposes Other electrical appliances Other purposes. Type of lamp Wattage Number Usage (hrs / day) Incandescent lamps Incandescent lamps Incandescent lamps Fluorescent lamps Compact Fluorescent lamps Compact Fluorescent lamps Description Wattage Number Usage (hrs / day) Rice cooker Immersion heater Electric Kettle Refrigerator Electric Iron Washing Machine Electric Fans Television Radio Domestic water pump Type of business Description No. of workers Elec. Consumption / month Monthly Income Small industry Rs. Commercial Rs. Agriculture Rs. Questionaire for RE schemes (section 1) Page 1 of [ 2 ] 5.40 5.50 5.60 5.70 5.80 6.00 6 . 1 0 6.20 6.30 6.40 6.50 6.60 7.00 7.10 7.20 8.00 8 . 1 0 8.20 8.30 8.40 9.00 9.10 9.20 9.30 9.40 9.50 Do you use electricity for preparing meals in your home? Yes / No / Sometimes If no, What is the main source of energy for cooking? Fire wood / LP Gas / Both Do you wish to start small industry using electricity ? Yes / No l f yes, 1 What is the type of industry you wish to start ? 2 What are the barriers you come across in getting electricity connection ? Do you wish to start small commercial activity using electricity ? Yes / No. " yes. 1 What is the type of commercial activity you wish to start ? 2 What are the barriers you come across in getting electricity connection ? Do you wish to start small agricultural activity using electricity ? Yes / No. I f yes, 1 What is the type of agricultural activity you wish to start ? What are the barriers you come across in getting electricity connection ? Do you think the life became more comfortable after getting electricity supply ? If yes, in which area, Yes / No Home lighting Cooking purposes Washing & Ironing cloths Water supply to the house Studying for children Use of television & radio Home security Sanitary & healthware Quality of Electricity supply. Light condition of electric bulbs : Low / Moderate / High Voltage fluctuations : Yes / No / Sometime Any damage occured to your electrical appliances due to high voltage after getting electricity ? If yes, how it occurred ? How many electricity supply interruptions in last month ? Nos. If there is a breakdown, how many hours CEB take to restore the supply after you inform them? Yes / No. If available, how? Can you manage your day to day works easily without electricity ? Street Lighting. Street lighting : Available / Not available Benefits you gained from street lighting ? Health services Is health center or dispensary available in your village ? Is it's service available even at night time for an emergency ? Do you think health service is improved after electrification of village ? Is any accident occurred due to electrification of the village? If yes, can / cannot / difficult within one hour within one day after one day only at junctions along the road Easy to travel at night time Improving security level of village Yes / No. Yes / No. Yes / No. Yes / No. Place of accident in your home | in your garden | in the scheme Nature of accident Electric shock / Death How many victims? How it occurred ? When it occurred ? Environmental effects. Did you cut trees in your garden in order to obtain electricity ? Did the CEB cut trees in your garden in order to install electricity lines ? Do you think trees are necessary to be cut down in order to minimize breakdowns and safety of people from electrocution ? Do you satisfy with the manner they did it ? Is there any dispute between villagers due to electrification? If yes, why ? Yes / No. Yes / No. Yes / No. Yes / No. Yes / No. Questionaire for RE schemes (section 1) Page 2 of S ec tio n (0 2) . Q ue st io nn ai re f or R E sc h e m e S ur ve y. 1. 00 G en er al d et ai ls o f t he S ch em e I D at e of r es ea rc h N am e of th e sc he m e: D at e en er gi ze d: C EB a re a: C on su m er S er vi ce C en tre : Pr ov in ce : D is tri ct : El ec to ra te : G SO D iv is io n: D iv is io na l Se cr et ar ia t: 2. 00 D ev el op m en t de ta ils o f t he s ch em e. At s ch em e op en At p re se nt Po pu la tio n of th e Vi lla ge To ta l n o. o f h ou se s N o. o f h ou se s co ve re d by C EB s ch em e N um be r o f h ou se s be yo nd 1 00 m a w ay fr om L T fe ed er 3. 00 T ec hn ic al d et ai ls . M ed iu m v ol ta ge s id e : 3. 10 C ap ac ity o f t he R E Su bs ta tio n : , M e d iu m V o |t . 3. 20 L en gt h of M V lin e to th e ta pp in g po in t o f M V fe ed er : 3. 30 C lo se st G rid S ub st at io n : In st al le d ca pa ci ty o f t he G rid S ub st at io n : M VA Pe ak lo ad o f G rid S ub st at io n : M VA 3. 40 D is ta nc e to th e gr id s ub st at io n fro m R E sc he m e ta pp in g po in t a lo ng th e M V fe ed er : 3. 50 C on di tio n of M V lin es fr om th e gr id s ub st at io n to R E sc he m e : Ty pe o f L in e Le ng th ( km ) C on du ct or s iz e D C o r S C To w er li ne ( b ac k bo ne li ne ) To w er li ne ^ M V fe ed er ) Po le li ne 1 Po le li ne 2 To ta l l en gt h (k m ) 3. 60 S w itc h ge ar s in s er ie s up to R E sc he m e fro m G SS a nd th ei r co nd iti on . Ty pe o f s w itc h ge ar N o. o f s w itc hg ea rs C on di tio n O C B LB S AB S Au to R ec lo se r D D LO — < Q ue st io na ire fo r RE s ch em e (s ec tio n 2) __ _ Lo ad cu rr en t (A ) F1 F2 F3 P ha se R P ha se Y P ha se B V ol ta ge o f Lo ng es t & he av yl y lo de d fe ed er (V ) F2 ( O m at ta s id e) V ol ta ge o f Lo ng es t & he av yl y lo de d fe ed er (V ) S ta rt M id dl e E nd V ol ta ge o f Lo ng es t & he av yl y lo de d fe ed er (V ) R V ol ta ge o f Lo ng es t & he av yl y lo de d fe ed er (V ) Y V ol ta ge o f Lo ng es t & he av yl y lo de d fe ed er (V ) B P ea k kV A de m an d of t he s ub st at io n : N .B . It is r eq ui re d to c on fir m t ha t no a ny d ef ec tiv e m et er s at c on su m er 's p re m is es a nd a ll m et er s ar e w or ki ng i n or de r du ri ng t he t es t pe ri od . E ne rg y m ea su re m en t of t he s ub st at io n. P er io d K W h fr om to K W h To ta l e ne rg y in pu t to t he L T lin es ( as r ec or de d in t he s ub st at io n m et er ) To ta l u se fu l en er gy o ut pu t. ( as r ec or de d in c on su m er 's m et er s) Lo ss o f en er qy Lo ss o f e ne rg y ( as a p er ce nt aa e) 4. 00 A ve ra ge L oa d Fa ct or : w ee kl y 5. 00 A ve ra ge P ow er F ac to r : w ee kl y 6. 00 N o Lo ad L os s of t he T ra ns fo rm er : w . 7. 00 A ll da y ef fi ci en cy o f th e tr an sf or m er : Q u e s ti o n a l fo r R E sc he m e (s ec tio n 2) pa ge 2 o f [ 2 ] Id en ti fi ca ti on D is ta nc e fr om T F. C on ne ct ed l oa ds N o. o f H ou se s M ed iu m M ed iu m N o of C om m er ci al S m al l M ed iu m N o of I nd us tr ie s S m al l N o of R el ig io us p re m is es C on di tio n of L T lin e C on di tio n of L T sw itc hq ea rs C on di tio n of w ay l ea ve s N B : S m al l ho us e be lo w 7 50 S q. ft. M ed iu m h ou se b et w ee n 75 0 S q. ft. t o 15 00 S q. ft . La rg e ho us e ov er 1 50 0 S q. ft. Li ne l en gt h in k ilo m et er s 3. 80 L oa d m ea su re m en ts o f t he s ub st at io n. S m al l in du st ry b el ow 1 0k V A sm al l co m m er ci al M ed iu m i nd us tr y be tw ee n 10 kV A 4 42 k V A . S ho ps . B ou tiq ue s, F ar m s et c ad jo in in g th e ho us e an d ar ea l es s th an 5 00 S q ft M ed iu m c om m er ci al : ' S ho ps , B ou tiq ue s, F ar m s et c ad jo in in g th e ho us e an d ar ea m or e th an 5 00 S q. ft. Appendix III Change of Line end voltage, current and fundamental wave form due to change of line resistance, load and the presence of harmonic voltages. 1. Changing the line resistance with keeping other variables is being constant. Changing Line Resistance - (Load & Vh constant) Vh =-18V, 150Hz,Odea. Df0.89 R (Ohm) I (Amp) Vend (V) 0.75 9.95 244.5 0.92 9.88 243 1.09 9.84 241.5 1.26 9.75 240 1.41 9.72 239 Harmonics effects on LV feeders p ag e j 0 f 5 2. Changing the line load with keeping other variables is being constant. Changing Load - (Resistance & Vh constant) R = 1.410hm,Vh = -18V,150Hz,0 dec , pf 0.89 Load (W) I (Amp) Vend (VI 1000 5.22 242.2 1500 7.69 242.5 2000 10.07 238.4 2500 12.37 - — — — — 234 3000 14.59 ,— 230 Line load Vs End voltage (R & Vh constant) : 244 242 S 240 oo 238 * 236 - 4 2 3 4 * 232- 230 228 - 900 1400 1900 2400 2900 Load (W) Harmonics effects on LV feeders page j 2f 5 Wave form of end voltage (without harmonics) Wave form of phase current (without harmonics) 3. Changing harmonic voltage with keeping other variables is being constant. Changing Vh - (Resistance & Load constant) R = 1.410hm, Load = 1925W pf0.89 Vh (150Hz,0) I (Amp) Vend (V) Vh (150Hz,0) I (Amp) Vend (V) -16.97 9.72 238.9 16.97 9.72 237.5 -33.94 9.74 240.4 33.94 9.71 237.7 -50.91 9.75 242.6 50.91 9.72 238.5 -67.88 9.75 245.2 67.88 9.73 239.8 -84.85 9.81 248.5 84.85 9.74 241.7 -101.82 9.84 252.1 101.82 9.76 244.2 -118.79 9.87 256.3 118.79 9.8 247.2 Harmonics effects on LV feeders page j 3f 5 Wave form of end voltage with (-ve) 3rd harmonics. ( - ve) 3rd Harmonic voltages Vs Current 9.85 - 9.75 -80 -60 -40 Harmonic wltage (V) Harmonics effects on LV feeders page j 4f 5 260 - > 255 -