GROWTH TRENDS OF DEMAND AND SUPPLY SIDE VARIABLES

IN KERALA ELECTRICITY SYSTEM: - AN ANALYSIS

 

Dr. Varghese Antony

Associate Professor, Department of Commerce

ST. Thomas College, Kozhencherry.

 

                        Abstract

            Energy is an independent parameter in the overall economic development activity of any country. It has become synonymous with progress in all fields of activities. Being a clean and versatile form of energy, electric power is one of the most important infrastructure sectors of national economy. Providing adequate and affordable electric power is essential for economic development, human welfare and higher standard of living. Uninterrupted  supply of adequate and reliable power at an affordable price would be the best ingredient to  generate quicker growth through better production in power based units. But unlike the other commodities electricity cannot be stored for future use. Its generation and consumption have to be simultaneous and instantaneous. Installing power generation, transmission and distribution capacity is a complex, time consuming and expensive process.

 

Introduction

            Electric power is a critical component as well as a determinant of a nation’s development. It is the most widely used form of domestic and commercial energy. Among the primary sources  of electricity, hydropower ranks high in the list of priorities in energy exploitation. It is one of the first non - animal energy resources harnessed by man. Today, nearly all hydro power is converted in to electricity. It is easily obtainable as it comes in mechanical form, which does not need conversion. In a hydro power system, electricity is produced through water, which is collected in a reservoir and a steady a stream is regulated through a specially built dam. This water is brought by pipes to a lower level where it flows through turbines. The rotation in the turbine provides mechanical energy, which is turned into electrical energy in the generators.

            Growth of electricity system in Kerala can be examined in terms of the changes in power system variables. Electricity system variables like installed capacity, generation, maximum demand, total number of consumers, connected load and other variables are mutually interactive and inter-dependant. Therefore, the study of electricity system in the state means the study of the trends in the growth of all these variables, which constitute the supply side and demand side of the state electricity system. An attempt is thus made to study the trends in the rate of growth of these variables - supply side and demand side - without which it is near impossible to analyse the key issues, which the electricity system has been witnessing.

Objectives of the study

1.    To study the major supply side variables affecting the Kerala electricity system.

2.    To study the major demand side variables affecting the electricity system of Kerala.

3.    To make a comparison in the growth rates of supply and demand side variables.

Electricity System Variables - Supply side

            The important system variables on the supply side include the installed capacity, Generation, Maximum Demand, Number of Transformers etc.

1.    Installed capacity

The installed capacity of the Kerala Electricity system, which was 38 MW in 1950,

increased to 2746 Mw as on 31-3-2010, the annual average compound growth rate being 7.39 per cent (Table - 1) During the first four five- year plan periods, perceptible increases were recorded in the installed capacity. Though installed capacity is the basic determinant of electricity generation; its rate of growth is not in proportion to the changes in other variables, as it appears to be based mainly on governmental decisions, which are influenced by non- economic factors.

 

2.    Generation

Electricity generation depends on several variables like installed capacity, internal

Maximum demand, the load factor, availability of sufficient quantities of water evacuation of power from the generating end etc. However, of all the factors affecting generation, installed capacity is the most crucial factors feeder. It is true that as the internal maximum demand increases, the electricity system may try to enhance the volume of generation beyond the desired level of generation capacity. However, for supplying adequate and quanlitative electricity on a sustained basis, installed capacity has to increase proportionately with electricity requirement. Details of growth in generation in the state is given in Table - 1

Table - 1

Plan wise Growth in installed capacity and Generation

Period

Installed capacity

    Mw

Changein Indices

Generation

   MU

Changein indices

1950

38

100

151

100

End of First plan 1956

86

226

350

232

End of Second  plan 1961

132.5

349

582

385

End of third plan 1966

193

508

842

558

End of Forth plan 1974

622

1637

2510

1662

End of Fifth plan 1979

1012

2663

5190

3437

End of Annual plan 1980

1012

2663

5119

3390

End of Sixth plan 1985

1012

2663

4885

3235

End of Seventh plan 1990              

1477

3887

5075

3361

End of Annual  plans  1992  

1477

3887

5326

3527

End of Eighth  plan 1997

1508.5

3970

5502.86

3644

End of Ninth plan 2002

2601.62

6846

7142.18

4730

End of Tenth plan 2007

2657.22

6993

7745.78

5130

As on 31-3-2010

2746

7226

7240.38

4795

Annual average

Compound growth rate (%)

7.39

 

6.66

 

     Source: 1) Kerala State Electricity Board, “Power System

                         Statistics”,  Thiruvanathapuram (Various Years)

                 2) KSEB, “Annual Administration Report”

                      Thiruvanathapuram (Various Years)

 

            Total electricity generated by the Kerala power system was 151 Mu in 1950. The rates of increase in generation up to the fifth five - year plan were considerably higher than the succeeding five - year plans. In the year 1978 - 79, there was a sudden increase in electricity generation, due to the increase in system demand and generating capacity made available by the commissioning of the Idukki hydel project in the fifth plan period. During the sixth, seventh and eighth five year plans, there was little or nominal increase in electricity generation. During the fourth year of the eighth five- year plan (1995 - 96), electricity generation registered an increase due to the commissioning of Kallada power project in 1994. The generation increased from 151 MU to 7240 MU between 1950 and 2010 at an annual average compound growth rate of 6.66 percent.

3.    Maximum Demand

Energy literature distinguishes between two types of maximum demand, namely maximum demand (internal) and Maximum demand (system). The maximum demand internal refers to the maximum demand taking into consideration the peak load demand of the consumers. The maximum demand system refers to the maximum demand that the electricity system in the state can meet during the peak hours (6.30 pm to 10.00 pm). Demand details are given in Table - 2. Power engineering principles explains that the system (electricity system within the state) shall be able to meet the internal maximum demand. In the context of Kerala, the system has been unable to meet the internal maximum demand from mid - 1980’s and therefore, load management techniques like load shedding and power cut have been implemented to overcome persistent power shortages. The gap between system demand and internal maximum demand is made up through power imports.

                       

 

 

 

 

 

 

 

 

 

 

Table: 2

Plan wise Growth in Demand and Number of Transformers

Period

Maximum Demand

    MW

(system)

Distribution       Lines (Kms)

No. of

Transformers 

 

High tension 

 

Low Tension

 

1950

25

(100)

1067

(100)

992

(100)

324

(100)

End of First plan 1956

63

(252)

2802

(263)

3783

(381)

845

(261)

End of Second  plan 1961

116 

(464)

5549

(520)

8899

(897)

2998

(925)

End of third plan 1966

174

(696)

6570

(616)

14189

(1430)

3930

(1213)

End of Annual plan 1969

353

(1412)

7241

(679)

16952

(1709)

4907

(1515)

End of Fourth plan 1974

500

(2000)

9645

(904)

25968

(2618)

8285

(2557)

End of Fifth plan 1979

852

(3408)

12645

(1185)

42507

(4285)

10330

(3188)

End of Annual plan 1980

854

(3416)

13348

(1251)

47606

(4799)

10821

(3340)

End of Sixth plan 1985

939

(3756)

16317

(1529)

71259

(7183)

12597

(3888)

End of Seventh plan 1990              

1171

(4684)

19127

(1793)

95938

(9671)

16394

(5060)

End of Annual  plans  1992  

1265

(5060)

25151

(2357)

108420

(10929)

18843

(5816)

End of Eighth  plan 1997

1235

(4940)

26444

(2478)

132864

(13393)

25940

(8006)

End of Nineth plan 2002

2333

(9332)

30971

(2903)

191930

(19348)

32585

(10057)

End of Tenth plan 2007

2742

(10968)

36419

(3413)

226128

(22795)

39848

(12299)

As on 31-3-2010

2998

(11992)

44683

(4188)

249687

(25170)

52300

(16142)

Annual average

Compound growth rate (%)

8.30

6.42

9.65

8.84

Source: 1) KSEB, “Power System statistics,” Thiruvanathapuram (Various issues)

            2)  KSEB, “Annual Administration Report” Thiruvanathapuram (Various issues)

Note    : Figures in brackets show the change in Indices.

 

                        Internal maximum demand in the state is based on the connected load and time factor. Given the time factor, as connected load increases, the internal maximum demand also increases. To meet the increase in internal maximum demand, the installed capacity of the system should have been increased at least 30 percent above the maximum internal demand, so that the system can meet the entire demand.

4.    Transformers

Transmission and distribution lines are connected to transformers of varying capacities.The transformer capacities are different in sub - stations and in High Tension (HT) and low tension (LT) distribution centers. If the transformer capacity of substation is below the expected rate, there will be higher levels of electricity loss and low voltage at the consumer end. Similarly if the transformer capacity is insufficient in the distribution centers, there will be higher levels of transformer loss and electricity losses. Therefore a reliable power system should install sufficient quantities of transformers to maintain load balance. Electric engineering principles explain that there is a standard normal range of distance between substations, so also with transformers. This range is to be maintained to reduce electricity loss and to provide desired level of voltage at the tail end of distribution lines.

            The number of transformers in Kerala increased from 324 in 1950 to 52300 in 2010 at an annual average compound growth rate of 8.84 percent (Table 2). Similarly the rate of growth in High Tension distribution lines is at 6.42 percent and that of Low Tension distribution lines is at 9.65 percent. However it is necessary to verify whether this much number of distribution transformers is sufficient to meet state’s electricity distribution system. A general view in this regard   is that even such a high number of distribution transformers are quite insufficient to dispatch better quality electricity due to the fact that there exist abysmally low levels of voltage in the state.

Electricity System Variables - Demand side

            The number of consumers and connected load are the major demand side variables that affect the growth of the electricity sector.

1.    Electricity consumers

       Electricity consumers consists of Domestic, Commercial, Industrial - LT, Industrial HT&EHT, public lighting, Agricultural, Public water works, Licensees and Railway Traction. The number of consumers in the state remained at  0.28 lakhs in 1950, which increased to 97.43 lakhs as on 31-3-2010 at an annual average compound growth rate of 10.25 percent (Table -3).The  rate of increase in the number of consumers was relatively higher from the sixth five - year plan onwords. The trend analysis of total power consumers in the state power sector shows that from fourth five year plan on words there has been considerable increase in the number of consumers. It further means that the demand for electricity started increasing at a faster rate since 1969. 

 

 

 

2.    Connected Load

Demand for electricity is expressed in terms of the connected loads, that is, the Electricity capacity (kw) requirement of consumers. When the electricity capacity requirements of all consumers are added together, we get the total connected load of the electricity system.

Table - 3     

Plan- wise Growth in Consumers and connected Load

Period

Number of

Consumers

(Lakhs)  

Changein indices   

Total Connected

Load (MW)

 

Changein indices  

1950

0.28

100

70

100

End of First plan 1956

0.79

282

142

203

End of Second  plan 1961

1.75

625

311

444

End of third plan 1966

3.25

1161

510

729

End of Annual plan 1969

4.40

1571

805

1150

End of Fourth plan 1974

7.77

2775

1231

1759

End of Fifth plan 1979

11.72

4185

1738

2483

End of Sixth plan 1985

22.17

7918

2803

4004

End of Seventh plan 1990              

31.90

11393

4166

5951

End of Annual  plans  1992  

36.98

13207

5526

7894

End of Eighth  plan 1997

49.23

17582

6089

8699

End of Ninth plan 2002

66.62

23792

8917

12739

End of Tenth plan 2007

87.14

31121

11466

16380

As on            31-3-2010

97.43

34796

15867

22667

Annual Average Compound

Growth Rate (%)

10.25

 

9.46

 

 

Source: 1) KSEB, “Power System statistics,” Thiruvananthapuram (Various issues)

            2)  KSEB, “Annual Administration Report” Thiruvananthapuram (Various issues)

            Connected load in the state has been steadily increasing and in the fourth, sixth and eighth five - year plan, the rate of increase is relatively faster as this is evidenced from the changes in its rate of changes of the indices (Table 3). It is also observed that the rate of changes of indices of connected load is relatively slower than that of total consumers. That is due to the fact that there is no one to one correspondence between consumers and connected load. Electricity demand by a consuming unit is not only the function of connected load but also the duration of electricity consumption by these units. There may be higher levels of connected load, but all this entire loads necessarily do not demand corresponding levels of electricity. Instead, even without an additional increase in connected load, there will be higher levels of electricity consumption if the duration of electricity consumption increases. The total connected load of the Kerala electricity system was 70 MW in 1950, which rose to 15867 MW as on 31-3-2010 at an annual average compound growth rate of 9.46 percent.

            The above analysis of the growth of demand and supply side variables in Kerala Electricity system reveals the annual average compound growth rate in the supply side variables and demand side variables between 1950 and 2010. The growth rate in installed capacity was at the rate of 7.39 percent where as the generation has increased at the rate of 6.66 percent. Maximum demand (system) has increased at the rate of 8.30 percent, High tension lines increased at 6.42 percent, Low tension lines at 9.65 percent and number of transformers at 8.84 percent. The demand side variables such as number of consumers increased at 10.25 percent and total connected load at 9.46 percent. The average growth rate in supply side variables like installed capacity, Generation, Maximum demand, Distribution lines and number of transformers was at 7.88 percent. The average growth rate in the demand side variables like number of consumers and connected load was at 9.86 percent. That shows that the annual average compound growth rate in the demand side variables is more than the annual average compound growth rate in the supply side variables.

 Conclusion

            The foregoing analysis of the growth of demand and supply side variables in Kerala Electricity system has thrown up several issues of serious concern. The major issues are that the key supply side variables such as installed capacity, generation, Maximum demand, distribution lines and number of transformers grew much slower than the demand side variables like number of consumers and connected load. This led to widening gap between electricity supply and demand, in turn, leading to very fast increase in electricity imports. The per capita electricity consumption increased steadily, but the units of consumption per actual consumer has been declining, a phenomenon reflecting shortage of adequate and reliable electricity supply. The need for new thinking, fresh management approaches for restoring operational efficiency and financial viability in electricity sector is more urgent now than ever before.

 Reference  

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