load management of power system using diversified demands

Abstract—Pakistan is a densely populated country. Only a small

part of her area is electrified. The people who are in the electrified

area are suffering from severe load shedding. A systematic load

management procedure related to demand side may improve the

situation is the research problem. The major objectives served by the

research are to analyze contemporary electricity status with a view to

drawing inference about demand supply gap and extracting benefits

from load management. Data supplied by National Power and

Dispatch Company of Pakistan, World Bank and outcome of survey

are analyzed with some simple statistical tools to test the hypothesis.

Analysis discloses that with properly managed uses of electricity with

load switch and rotational week-end can improve the concurrent

condition of electricity. Moreover, introducing some remedies like

smart distribution system, reducing system loss etc are recommended

to improve load situation through demand side management.

Keywords— Electricity, Energy Crisis, Load Management, Load

Switch.

I. INTRODUCTION

AKISTAN is a country endowed with huge natural

resources. There are lots of sources of energy from the

nature. Electricity is a type of converted energy from another

form of energy. According to Global Energy Network Institute

[1], Pakistan has small reserves of oil and coal, but potentially

very large natural gas resources. Commercial energy

consumption is around 71% natural gas, with the remainder

almost entirely oil (plus limited amounts of hydropower and

coal). Only around 79% of the population has access to

electricity, and per capita commercial energy consumption is

among the lowest in the world. The rest of the total population

in Pakistan is still in the dark. Pakistan's per capita electricity

generation is still among the lowest in the world. A large

number of populations of Pakistan are still leading their life in

the dark. Over 30% of people depend on traditional energy

sources such as firewood, cow dung and agricultural residues

for their energy needs [2]. In the year 2008, the amount of

electricity production of Pakistan was 90087 GWH (table I).

At the present production level of electricity, only proper

management of its distribution and load may assure better

consumer satisfaction through reduced load shedding. The

Muhammad Zakria Khan, NWFP University of Engineering and

Technology, Peshawar Pakistan, (+923139191891; e-mail: engrahmad75@

yahoo.com).

Professor Dr.Naeem Arbab, NWFP University of Engineering and

Technology, Peshawar Pakistan. He is now with the Department of Electrical

Engineering,NWFP Engineering University, Pakistan.

main research problem of this paper is to manage the supply

side of electricity as a tool for crisis management.

Electricity crisis means actual demand is higher than the

actual supply. Officially the country„s present power demand

is about 17280 MW (table II) and shortage 4747 MW (table

II) per day on an average. Load management is a program

which reduces the demand of electricity at any specific time

period. The prime objective of Load management system is

―Manage The Peak‖. It is important to reduce cost factor of

energy and run our less efficient power plant to meet high

energy demand.

Demand for energy during peak is alarmingly increasing day

by day. Due to this there is a significant gap between demand

and supply of electricity and occurs load shedding [5]. Load

management is a strong weapon to beat this peak. So it is a

challenge for Govt. and power generation authority for

ensuring adequate, reliable and quality power. Load

management for electricity is a crying need to develop the

sector in a sustainable manner. Only it can provide more

benefit to our citizens and environment.

II. LOAD MANAGEMENT IN PAKISTAN

Load management can make the electricity demand-supply

trade off. Properly managed use of electricity can eradicate the

sufferings of load shedding. The cost of

load shedding is not only physical sufferings but also financial.

Because of shortage in power supply, countrywide financial

operations are hampered. Load management is a technique that

can be used to spread evenly the surplus of off-peak period for

peak period use. Load management can be implemented either

weekly or daily or both basis.

A. Load management by week-round equal electricity

distribution

Load management is a technique to reduce the load

shedding minimum. Load shedding is deficiency in the

fulfillment of demand due to shortage of supply of electricity.

According to Table III, demand for electricity on Tuesday is

only 15538 MW which is topped on Sunday at 17549 MW. .

In 7-day week, the demand for electricity is not equal. On the

specific days all the Governments and autonomous

organization consume less power. Moreover, a good number

of private offices including bank and educational institutions

enjoy holiday on certain days. As a result, the shortage of

electricity is reduced at the specific days of any week which is

displayed in table III. If the rotational holiday policy is

Load Management of Power System Using

Diversified Demands in Pakistan

Muhammad Zakria Khan, and Professor Dr. Naeem Arbab

P

Intl' Journal of Computing, Communications & Instrumentation Engg. (IJCCIE) Volume 1 Issue 1 (2014) ISSN 2349-1469 EISSN 2349-1477

http://dx.doi.org/10.15242/ IJCCIE.E1113086 103

introduced, electricity shortage may be reduced to some extent

as the Figure 2 depicts. Excess load shedding from Monday to

Thursday during the week can be plateau over the week

through rotational weekend policy for different institutions

including Government organization, Financial Institutions,

Educational Institutions, Shopping mall and Factories etc.

TABLE II

DAY-WISE ELECTRICITY GENERATION, DEMAND, LOAD SHEDDING, SHORTAGE (MW) [4]

TABLE I

ELECTRICITY STATISTICS FROM WORLD BANK [3] Indicator Name 2005 2006 2007 2008 2009 2010

Electricity production from oil, gas and coal (% of total) 64.5 65.2 66.8 67.9 67.5 62.7

Electricity production from hydroelectric (GWh 30862 31953 28707 27784 28093 31811

Electricity production from hydroelectric (% of total) 30.00 32.90 32.5 30.0 29.4 33.7

Electric power transmission and distribution losses (GWh) 22765 22015 18603 19187 18793 15184

Electric power transmission and distribution losses (% of

output) 24.26 22.38 19.44 20.94 19.70 18.45

Electricity production from natural gas (GWh) 41286 35811 32923 29678 28079 25879

Electricity production from natural gas (% ) 44.00 36.41 34.41 32.39 29.43 26.67

Electricity production from oil (GWh) 19071 28162 30848 32433 36218 33255

Electricity production from oil (% of total) 20.32 28.63 32.24 35.4 37.96 39.67

Electricity production (GWh) 84321 85670 87907 90087 90567 94453

Electric power consumption (GWh) 71067 76335 77088 72439 76607 79269

Electric power consumption (KWh per capita 450 474 470 434 450 458

Date Days Minimum

Generation

Maximum

Generation

Maximum

Demand

Load

Shedding

Total

Generation

(MKWh)

Savings

After load

management

03/08/13 Monday 10059 11916 17297 5381 279 1929

04/08/13 Tuesday 10260 12463 17321 4858 277 1511

05/08/13 Wednesday 10589 12408 17397 4989 264 1710

06/08/13 Thursday 10743 12594 17502 4908 283 1604

07/08/13 Friday 10720 11855 17215 5360 289 2011

08/08/13 Saturday 10168 12491 17402 4911 281 2147

09/08/13 Sunday 10742 12611 17466 4855 270 1755

10/08/13 Monday 11039 12249 17549 5300 277 2047

11/08/13 Tuesday 10694 11114 15538 4424 270 1388

12/08/13 Wednesday 10265 12282 16963 4681 277 954

13/08/13 Thursday 10425 11930 16800 4870 280 1431

14/08/13 Friday 10070 12158 16245 4087 288 2571

Average 10696 12533 17280



B. Load Management by Load Switch

The daily electricity load is not even throughout the day. It

varies from time to time. From table III, of the total users of

electricity, around 45% is domestic users; 11% is agricultural

uses; 28% is industrial users and 7% is commercial users. The

rest is the other users‟ share of 6.50%. Domestic load can me

managed with planned uses. Some appliance can be kept

switch off in the peak period. Air conditioners, woven, coffee

heater, washing machine etc. should not use during peak hours

of the day. Load switch is devices that will keep some specific

device switch off for a pre specified period of time. This

device helps to adopt the planned use of electricity and easily

speared out limited electricity throughout the day evenly to

ensure balanced consumption.

III. HYPOTHESIS OF THE STUDY

The hypothesis of the study is set as an improvement of

electricity management is obtainable in terms of lower

shortage from the proper load management even only demand

side. The amount of electricity saved from proper management

and efficiency in supply may reduce the shortage of electricity

to a great extent.

IV. ANALYSIS AND FINDINGS

Data are analyzed and sorted out for inferring some

recommendations and conclusion about the research problem.

According to World Bank report, the coverage of energy

sector in Pakistan is limited, service quality is low, theft of

power and gas is rampant, and utilities are bankrupt and live

on state subsidy.

A. Daily Load Management

Day wise average maximum electricity generation is 12591

MW (table II) against the daily average demand of 17423 MW

(table II). The shortage is on an average 4468 MW (table II)

which includes system loss. If it is assumed that the supply

side is constant, electricity situation could be improved by

managing load of electricity. Scattering daily peak among the

off-peak, load shedding and shortage can be reduced. Some

office and household appliance can be kept switch off during

peak. From the survey on five hundred and fifty people, it

reveals that 46.64% electricity (table II) is consumed by

households. Industry consumes 27.60 % (table IV) and

agriculture uses 11.17% (table IV). Of the household„s

consumption, lighting, fans & A/C and refrigeration consume

40%, 27% and 22% respectively (table IV). Industrial uses

consist of motor, lighting and other uses which could be

minimized to some extent during peak. Agriculture uses

electricity widely for irrigation and grain husking as the survey

reveal. Peak hour electricity demand may be avoided by

agricultural consumptions. Being strategic about electricity

use, people can save 5.79% electricity that will be scattered

while peak demand arises. Another way of handling daily peak

is to use load switch as the Figure 2 reveals. Use of this switch

can reduce electricity consumptions of some households and

official appliances. This is useful in saving a handful of energy

and is thus useful for the overcoming of energy demands of the

country.

B. Weekly Load Management

From the analysis of data, another fact is disclosed from

Figure 1. A Monday to Monday load shedding diagram depicts

that the amount of weekend load shedding is not constant. This

is because of varying industrial consumption and varying

public and other consumption which is around 32.19% (table

IV) of total daily electricity consumption. Using rotational

usage may be an effective way to scatter other day's load

shedding to the next maintaining a constant lower value of

load shedding by managing peak. As the arrows in Figure 1

indicate, maximum load shedding of around 5321 MW and

minimum 4424 MW load shedding will be adjusted at straight

line on an average throughout the week. 5.

V. RECOMMENDATIONS

A. Smart Distribution System

According to Pakistan Energy Book (2010) [6], the total

length of distribution lines of 33 KV is 3,763 km, 11 KV is

9,449 km. and 0.4 kV is 15,965 km. i.e. total distribution lines

are about 29,177 km at the end of FY 2009. Efficient

distribution line and its proper maintenance can reduce system

loss to a good extent. Moreover, illegal use of electricity

should be stopped. The smart distribution system will reduce

the system. According to Khan S. I. & Islam A. (2012), the

concept of smart grid refers to a ―Digital Upgrade‖ of

distribution and long distance transmission grids to optimize

current operations by reducing the losses, as well as open up

new markets for alternative energy production.

B. Reducing System Loss

System loss is slicing a good quantity of electricity both in

production and distribution line. The system loss is increasing

day by day. It is estimated that the total transmission and

distribution losses in Pakistan amount to one-third of total

generation, the value of which is equal to US$247 million per

year. Proper concentration and some corrective measure are

very emerging for improvement of the supply side of

electricity. Reduction in system loss is the only supply side

management for load management in a state of fixed electricity

generation plant [8]. According to the PEPCO Annual Report

(2009), distribution loss in DISCOS own distribution zones

has decreased to 13.57 % from 14.43% in FY 2009. In

addition, taking some initiatives, this distribution loss may be

decreased to some more extent.

C. C. Alternative Energy

Alternative energy sources such as solar energy, wind

energy and nuclear energy are a permanent solution to the load

management problem [9]. According to the World Bank

funded market survey, there is an existing market size of 0.5

million households for Solar Home System (SHS) on a free-

for-service basis in the off grid area of Pakistan. This

assessment is based on current expenditure levels on fuel for

lighting and battery charging being substituted by SHS (World

Bank, 1998). Moreover at present the national grid is serving



only 50% of the nearly 10,000 rural markets and commercial

centers in the country which are excellent market for

centralized solar photovoltaic plants (World Bank, 2000).

D. Large Scale Use of Prepaid Meter

Prepaid meter can implement budgetary control on the

electricity bill of households and commercial use. To keep

control over expenditure, people may feel interested in using

the prepaid meter. Moreover, the use of the meter will be

helpful to limit the consumption of electricity use. It can

ensure reduction of system loss and can save few MW of

electricity in the national grid. From the consumers„

perspective, prepayment systems may result in a better

understanding of how much energy is being consumed,

inducing more control of energy use and budget management

[10], [11].

E. Public Private Partnership (PPP)

In the power sector, the role of the Pakistan Government

should be limited only to electrical regulations, electrical

safety, consumer protection, monopoly prevention, nuclear

energy development; support for oil, gas and coal exploration

required to meet the energy needs of Pakistan. The policies

created should be those which encourage local technical

innovations by private enterprises, growth of local expertise

and electrical industries, support for the free market economy

and increase in employment opportunities in electrical power

industries in Pakistan. [12]

F. Energy week

Celebration of energy week plays a vital role in load

management. Most of households and official users are not

conscious about savings of electricity from proper utilization.

A handsome percentage of electricity losses due to

unconsciously use. A switched on fan or light or AC room

without a man waste a good quantity of electricity. It can serve

the crisis moment of electricity during the peak. To make the

mass people conscious about proper utilization of electricity

and saving there from with a bit care some program like

observing energy week „may be an effective tool.

G. Local Energy Production

A considerable quantity of electricity is lost during

transmission. If the distribution distance could be minimized

by local production setup, transmission loss may be avoided to

a good extent. In 1998, Pakistan also adopted a Small Power

Generation Policy to encourage development of small local

generations „projects of up to 10 MW in capacity in

underserved areas [14]

VI. CONCLUDING REMARKS

With the present level of electricity production Pakistan

may improve her electricity situation using the proper load

management system. There is some widely used mechanism

for management of load of electricity during. Some require

huge investment and technical know-how which are not

feasible to apply in developing countries like Pakistan. As the

supply side is not improvable over night, concentration goes to

demand side for improving electricity crisis. Some artificial

crisis is manageable with proper tools that even do not require

huge investment. The research discusses about these

mechanisms. This research is helpful and contributory one for

policy making about electricity in Pakistan. But it cannot be

staid this is an absolute in all aspect.

REFERENCES

[1] Global Energy Network Institute, National Energy Grid Pakistan,

available from http://geni.org/library/national-energy- grid/Pakistan

/index.html , last accessed 05, September 2013.

[2] WEC- World Energy Council, Extract from the survey of Energy

Resources 2001, Energy Information Centre, WEC, London.

[3] World Bank, available from http://Data.worldbank.org/indicator

/EG.USE.ELEC.KH.PC

[4] National Transmission and Dispatch Company, June 2013 report.

[5] Noor Alter, Shabib Haider Syed, “An Empirical Analysis of Electricity

Demand in Pakistan”, International Journal of Energy, Economics and

Policy, vol.1, pp.116-139, 2011.

[6] PEC Annual Report (2010), Pakistan Energy Book (HDIP).

[7] Khan S.I, Islam.A, “A Smart Energy Grid, Energy and Power”, 2012.

[8] Sifat Shah, M.K.L. Bhatti, “Crisis of Electrical Energy in Pakistan and

Guideline for Policy Makers”, IJENS, 2009.

[9] Simon Ronald, “Rural Electrification with Renewable Energy

Technologies “, ARE‟s Technology Working Group, 1st Edition, June

201.

[10] G.W.Hart, “Nonintrusive Appliance Load Monitoring”, in Proceedings

of the IEEE, pp.1870- 1891 Dec 1992.”

[11] Ross Anderson, Shailedra Florurid,”Who Controls The Off Switch”.

[12] Role of Private Sector-cross Border Energy Trade in South Asia, South

Asia Regional inaugural conference.

[13] John Hassder, PerKrusell, Conny olosson, “Energy Saving Technical

change”, NBER Working Paper, Oct 2012,

[14] Catherine Wofram, Orie Shielef and Paul Gertler, “How will Energy

Demand Develop in the Developing World”, Energy Institute Haas

Working Paper Series, January 2012

TABLE III

NUMBER OF CONSUMERS (CATEGORY WISE) [6]

Categories Domestic Agriculture Industries Others Total

Year Domesti

c

Domest

ic

Users

in %

Agric

ulture

Agricult

ural

Users in

%

Industria

l

Industria

l Users

in %

Comm

ercial

Commer

cial

Users in

%

OTHE

RS

Other

Users

in %

Total Growth

of

Users

in %

2004-05 27601 45 6988 11 18591 30.31 4080 6.65 4067 6.63 61328 6.67

2005-06 30720 45.44 7949 11.70 19803 29.29 4730 6.99 4402 6.51 67603 10.23

2006-07 33335 45.84 8176 11.24 21066 28.97 5363 7.37 4389 6.03 72712 7.56

2007-08 33704 45.91 8472 11.54 20729 28.24 5572 7.59 4701 6.40 73400 0.95

2008-09 32282 45.87 8795 12.49 19330 27.46 5252 7.46 4930 7.00 70371 -4.13

2009-10 34282 46.09 9689 13.03 19823 26.66 5605 7.53 4958 6.66 74348 5.65

2010-11 35962 46.64 9045 11.17 21267 27.60 5870 7.61 4987 6.46 77099 3.7



http://data.worldbank/

TABLE IV

COMPOSITION OF ELECTRICAL DEMAND BY DIFFERENT SECTORS (SOURCE: WORKED OUT)

Consumer Category Consumption Consumption Pattern

(MW)

In

Percentage

Savings from

Load

Management(MW)

(i) Households 46.64% Lighting 3995.77 40 % 486.94

(9989.44 MW) Fan& A/Cs 2697.14 27 % 131.50

Refrigeration 2197.67 22 % 52.60

Others 1098.79 11 % 105.20

(ii) Agriculture 11.17% Pumps 1005.71 40 % 95.30

(2512.5 MW) Grain Husk 1256.25 50 % 122.53

Lighting 251.25 10 % 04.98

(iii) Industry 27.60% Motors 4135.5 70 %

(5907.5 MW) Lighting 472.60 8 % 11.69

Others 1299.66 22 %

(iv) Public and

Others

14.59% Lighting 1991.53 65 % 163.42

(3063.9 MW) Others 1072.05 35 % 70.57

Total

(21471 MW) Total (21471)

MW

1244.73

Savings from Load Management In Percentage 5.79 %

Fig. 2 Block diagram of how a load management switch works. (source: load management in apex, north Carolina)

Fig. 1 Week-round load (source: worked out)

DIAGRAM OF LOAD MANAGEMENT

Thermostat Switch Load Management

Switch Air-Conditioning

Compressor Motor



load management of power system using diversified demands

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