1. power system losses introduction

National Power Training Institute of Nigeria
BY
KHALIL Y. A.
POWER LOSSES -
INTRODUCTION
AUGUST, 2019

Getting to Know Each Other…
• Full Name
• Profession/Job role
• Years of experience
• What would you like to get out of this
Training?

Rules
WC
Smoking area
Course agenda
Emergency exit
Mobile phone
E
xi
t

Learning methods
Lecturing
Open Discussion
Group exercise
Case Studies

.................................power trainer with a difference
• Explain the concept of
power loss and its effect as
it relates to power system
• Classify power losses and
identify the causes and
effects of each class
COURSE
OBJECTIVES
At the end of this course all the participant should be able to:

• What is Energy?
o Ubiquitous definition
• Is the ability to do work
• Classification of Energy
o Primary: obtained from nature
– Renewable Energies: Solar, Wind, Hydro, Geothermal, Tidal, and
Biomass
– Fossil fuels: Crude oil, Natural Gas, and Coal
– Nuclear: Uranium, Plutonium etc.
o Secondary/Final: obtained by converting Primary Energy
– Steam
– Electricity
– Petroleum products: PMS, AGO, etc.
6
UNDERSTANDING ENERGY, CLASSIFICATION & UNITS

• Units of Energy
o Electrical: Wh, kWh, MWh, GWh, TWh
o Mechanical: J, kJ, MJ, GJ, TJ
o Chemical: Cal, Btu,
7
Understanding Energy, Classification
& Units [2]
Figure 1: Shares of energy sources in total global primary energy supply in 2008 (492 EJ)
Source: IPCC, Renewable Energy Sources and Climate Change Mitigation, 2012

• Underlying principle behind Energy conservation
o Law of Energy conservation:
• Energy can never be created nor destroyed but converted
from one form to another
8
Energy Conversion and Efficiency with
focus on the value chain of Electricity sector
Energy Input Equipment Useful Energy Output
Chemically bound energy in coal Steam boiler Steam
Electricity Electric Motor Mechanical shaft energy
Electricity Incandescent light bulb Visible light
Steam Steam Turbine Mechanical shaft energy
Low voltage electricity Step up transformer High voltage electricity
Mechanical shaft energy Water pump Flow work
Chemically bound energy in
diesel fuel
Diesel generator set Electricity

• Energy conversion process along the electricity value chain
9
Energy Conversion and Efficiency with focus on the value
chain of Electricity sector [2]
v
v

• Conversion losses & Efficiency
o Almost no energy conversion process is ideal or without loss
o Efficiency is a measure of the degree at which one form of energy is converted to another
o Two methods of calculating Efficiency
• Useful energy output vs energy input
• In terms of energy loses
10

• Calculating energy efficiency savings
o Where
11

Losses:
 Technical/Non-technical losses
Revenue collection:
 Average collection period
 Bad debts collection
 Revenue assurance & back-billing
Customer focus:
 Customer complaints
 Customer satisfaction
 Retaining customer’s loyalty
Keeping the light on:
 Reduce breakdown
 Faster response to interruption
Cost per unit:
 Managing CPU rise (2% - 3% annually)
 Keeping CAPEX & OPEX reasonably low
BUSINESS CHALENGES

POWER FLOW – IDEAL CONDITION

ELECTRICITY BILLING COMPONENT
Bill element Tariff
A
Tariff
B
Tariff
C
Tarif
f
D
Tariff
E
Tariff
G
a Energy consumed √ √ √ √ √ √ Sales of energy usage
b Power (Max Demand) √ √ Charge for capacity
c Power factor √ √ √ √ Penalty for
poor efficiency
level of
electricity
usage
d Welding charge √ Charge for capacity
for customer who
does not pay for Max
demand
e Temporary supply √ Charge for supply
required for less than
6 months

The Loss Mitigation Paradox of the
African Power Sector
• Focus of loss mitigation across the Power sector globally & in Africa is on
Transmission & Distribution losses
• Very little attention is paid to losses in Power Generation globally for
obvious reasons. However, why should it be the same case in Africa, when:
o It could arguably be the 2nd biggest source of loss in the African power sector after
Distribution, depending on the fuel source, technology and level of maintenance
o The tariff for electrical power takes into account first, the cost of power production,
and its associated losses
o About 2/3rd of the total power generation in Africa are from thermal, powered by
fossil fuels (having huge potential of losses)
o The African Power market is yet to be competitive
o It is the beginning of losses in the value chain
19

The Loss Mitigation Paradox of the
African Power Sector [2]
20
ηgen
ηtrans
ηdist
Network Efficiency = ηtwrk = ηtrans × ηdist

OVERVIEW OF NIGERIANELECTRICITYINDUSTRY
Distribution System
Power Station
Substation
Transmission Lines
Control Centre
Transmission System 3
330KV330KV
132KV
33KV
11KV
11/0.415/0.240KV

Overview of NigerianElectricityIndustry
Generation. Nigeria has 12,522MW of installed
capacity, but due to maintenance, gas, water and
transmission constraints, an average of only 5000MW
of capacity is operational
Primary energy — gas. The majority (85%) of
installed capacity is fueled by gas. Availability of gas
molecules is low due to insufficient production, economic
disincentives, inadequate infrastructure and frequent
vandalism.

Transmission. Nigeria’s transmission system has the
capacity to transmit ~6,894MVA but is disrupted by
system collapses and frequent forced outages. Currently,
transmission capacity is higher than operational
generation capacity, but transmission will rapidly become
a constraint due to increasing operational capacity
Distribution. Nigeria’s distribution companies suffer
significant losses, with ~46% of energy lost due to
technical, commercial and collection issues.

Today,`(2017) ~95 million Nigerians (~55% of the population)
have no access to electricity and those who are connected
to the grid face extensive power interruptions. Systemic
issues affect all phases of the power value chain
(generation, gas supply, transmission and distribution)
forcing Nigerians to rely on self-generation. According to the
World Bank, an estimated 41% of Nigerian businesses
generate their own power supply to augment the national
grid supply.
At 126kWh per capita, Nigeria lags far behind other developing
nations in terms of grid-based electricity consumption. Based on the
country’s GDP and global trends, electricity consumption should be
four to five times higher than it is today.

Electricity access in West Africa - 2013
Region Population
without
electricity
millions
National
electrification
rate %
Urban
electrification
rate %
Rural
electrification
rate %
Benin 7 29 % 57 % 9 %
Burkina Faso 14 17 % 56 % 1 %
Cabo Verde 0 94 % 100 % 84 %
Côte d'Ivoire 15 26 % 42 % 8 %
Gambia 1 36 % 60 % 2 %
Ghana 7 72 % 92 % 50 %
Guinea 9 26 % 53 % 11 %
Guinea-Bissau 1 21 % 37 % 6 %
Liberia 4 10 % 17 % 3 %
Mali 11 26 % 53 % 9 %
Niger 15 15 % 62 % 4 %
Nigeria 96 45 % 55 % 37 %
Senegal 6 55 % 90 % 28 %
Sierra Leone 6 5 % 11 % 1 %
Togo 5 27 % 35 % 21 %

POWER SYSTEM LOSSES
• Electric power is generated in power stations
and delivered through the transmission and
distribution systems to the customer.
• Energy losses can occur in each part of the
power system until reaching the customer’s
meter.
• Power system energy losses are divided into
categories based on where the losses
happen and the cause of power losses, as
indicated below:

LOSSES cont.
• Power station losses – energy consumed by the equipment
in support of power generation, it is also called power
station auxiliary load or power station own usage.
• Power System losses – losses incurred by moving power
through the transmission and distribution systems, including
transformers, over-head line conductors, aerial cables or
underground cables, and low voltage (LV) secondary service
wires.

POWER STATON LOSSES
• Losses are
dissipated as
heat, during the
operation of a
large generator.
The various parts
that produces
such heat are
shown in the pie-
chart.
29

LOSSES cont.
• For Transmission and Distribution, there
are no station losses since they do not
own any power plant. This could happen
where there is Distributed generation
• Power system losses occur in the
Transmission and Distribution chain.
• Losses in the system losses category
consist of both
• Technical and Non-technical losses

•
Classification of power Losses

LOSSES cont.
• In electricity supply to final consumers, losses refer to the amounts of
electricity injected into the transmission and distribution grids that are
not paid for by users.
• Total losses have two components: technical and non-technical.
• Technical losses occur naturally and consist mainly of power dissipation in
electricity system components such as transmission and distribution lines,
transformers, and measurement systems.
• Non-technical losses are caused by actions external to the power system
and consist primarily of electricity theft, non-payment by customers, and
errors in accounting and record-keeping.
• These three categories of losses are respectively sometimes referred to as
commercial, non-payment (collection), and administrative losses.

LOSSES cont.
• Metering and billing for electricity actually consumed
by users is integral to commercial management of an
electricity utility.
• Another critical task is collection of the billed amounts.
• Effective performance in both functions is critical to
ensure the financial viability of the company.
• From the operational point of view, metering-billing
and collection are separate functions and they require
specific management approaches.

TECHNICAL LOSSES
• Optimization of technical losses in electricity transmission and
distribution grids is an engineering issue, involving classic tools of
power systems planning and modelling.
• The driving criterion is minimization of the net present value
(sum of costs over the economic life of the system discounted at
a representative rate of return for the business) of the total
investment cost of the transmission and distribution system plus
the total cost of technical losses.
• Technical losses are valued at generation costs.

Technical losses
Line Losses Transformer Losses
•Resistive losses •Core losses
•Unbalanced loading •Hysteresis Loss
•Mismatch on conductor sizes •Eddy Current Loss
•Winding losses
•Leakage Flux

TECHNICAL LOSSES cont.
• Technical losses represent an economic loss for the country, and
its optimization should be performed from a country’s
perspective, regardless of the institutional organization of the
sector and ownership of operating electricity utilities.
• Although each case has its specific characteristics, depending on
the current and future values of generation costs, some general
comments can be made.
• Energy experts agree that, in the next two decades, global prices
of primary energy resources (oil and other fossil fuels) will be
rising in real terms.

TECHNICAL LOSSES cont.
• In its World Energy Outlook 2008, the International Energy Agency forecasts
world oil prices rebounding to about US$130 (2007 U.S. dollars) per barrel in
2030.
• Other forecasts differ in absolute values, but not in the upward tendency of
energy prices.
• On the investment side, prices of equipment in the electricity sector (generation,
transmission and distribution) steadily rose this decade until the global financial
crisis that began in the 3rd quarter of 2008.
• Against these price trends, the total costs of technical losses tend to exceed
investment costs of transmission and distribution equipment required to reduce
them to their optimum value, more so where a significant portion of generation is
based on fossil fuels.
• This tendency is accentuated if environmental costs of power generation (harmful
local pollutants as well as greenhouse gas emissions) and increasing difficulties in
achieving social acceptance of new power plant construction (regardless of fuel
type and technology) are taken into account.

Technical Losses Breakdown
39
Technical
Losses
Transformer
Losses
Primary
Feeder
Losses
Copper
Loss
Core
Loss
Distribution
Transformer
Power
Transformer
Core
Loss
Copper
Loss
Secondary
Feeder
Losses
• Technical Losses are caused by electric power flowing through
impedances of conductors, transformers, and any other
equipment on the path of delivering electric power to customers

Where Technical Losses Occur
40
Substation
Transformer
Gen
16/330KV 330/132KV 132/33KV 33/11KV 11/0.415KV
Generation Transmission
System
Distribution Systems
Power Systems in Nigeria
Feeders and
Laterals
Service
Transformer
240V
Utilization
Voltage
Secondary
System
Service
Drops
240V
Consumers

NON-TECHNICAL LOSSES
• Non-technical losses represent an avoidable financial loss for the utility.
• Although it is clear that the amounts of electricity involved in non-
technical losses are being consumed by users that do not pay for them,
experience shows that a significant percentage of those amounts (in
some cases more than 50 percent) becomes reduced demand when
those users have to pay for that electricity, because they adjust their
consumption to their ability to pay for electricity services.
• That reduction in demand has exactly the same effect as a reduction in
technical losses: less electricity needs to be generated.
• Thus, from the country’s perspective, reductions in non-technical losses
are also positive.

NON-TECHNICAL LOSSES cont.
• From a social point of view, non-technical losses have several perverse effects.
• Customers being billed for accurately measured consumption and regularly
paying their bills are subsidizing those users who do not pay for electricity
consumption.
• There is a wide range of situations creating non-technical losses.
• A classic case is a theft of electricity through an illegal connection to the grid or
tampering of a consumption meter.
• But examples also include unmetered consumption by utility customers who
are not accurately metered for a variety of reasons. In all the cases some level
of poor management of the utility in execution of its operations is present.

• Electricity theft is de facto subsidization of those who steal by
customers regularly paying bills according to their
consumption.
• The same usually applies in the case of unmetered customers,
unless this situation is explicitly and transparently defined by
the competent authorities and reflected in the legal and
regulatory framework of the sector—
• In some countries some categories of consumers (e.g.,
agriculture users in India and Bangladesh) are unmetered and
pay a fixed amount for electricity irrespective of the amounts
consumed, which means in practice that they are subsidized by
consumers in other categories, tax payers, or both.

• Depending on the financial situation of the power sector,
the savings from reductions in non-technical losses could be
channelled to;
• a) reduce tax-payers subsidies or tariffs paid by customers,
• b) achieve an average tariff level allowing recovery of costs
reflecting efficient sustainable performance (critical to
assure service quality),
• c) subsidize consumption of selected categories of socially
sensitive existing users, or
• d) extend access to electricity supply to currently un-served
population (in general the poorest and socially
unprotected).

Main reasons for non-technical
losses
• 1. Power theft
• Theft of power is energy delivered to customers
that is not measured by the energy meter for
the customer.
• Customer tempers the meter by mechanical
jerks, placement of powerful magnets or
disturbing the disc rotation with foreign
matters, stopping the meters by remote control.

Reasons for Non-technical
losses
• 2. Metering inaccuracies
• Losses due to metering inaccuracies are defined as the difference
between the amount of energy actually delivered through the
meters and the amount registered by the meters.
• All energy meters have some level of error which requires that
standards be established. Measurement Canada, formerly
Industry Canada, is responsible for regulating energy meter
accuracy.
• Statutory requirements are for meters to be within an accuracy
range of +2.5% and – 3.5%. Old technology meters normally
started life with negligible errors, but as their mechanisms aged
they slowed down resulting in under-recording. Modern
electronic meters do not under-record with age in this way.
• Consequently, with the introduction of electronic meters, there
should have been a progressive reduction in meter errors.
Increasing the rate of replacement of mechanical meters should
accelerate this process

losses
• 3. Unmetered losses for very small load
• Unmetered losses are situations where the energy
usage is estimated instead of measured with an
energy meter. This happens when the loads are very
small and energy meter installation is economically
impractical.
• Examples of this are street lights and cable television
amplifiers.

losses
• 4. Unmetered supply
• Unmetered supply to agricultural pumps is one of the major
reasons for commercial losses. In most states, the agricultural
tariff is based on the unit horsepower (H.P.) of the motors. Such
power loads get sanctioned at the low load declarations.
• Once the connections are released, the consumers increasing
their connected loads, without obtaining necessary sanction, for
increased loading, from the utility. Further estimation of the
energy consumed in unmetered supply has a great bearing on the
estimation of T&D losses on account of inherent errors in
estimation.
• Most of the utilities deliberately overestimate the unmetered
consumption to get higher subsidy from the State Govt. and also
project reduction in losses. In other words higher the estimates of
the unmetered consumption, lesser the T&D loss figure and vice
versa.
• Moreover the correct estimation of unmetered consumption by
the agricultural sector greatly depends upon the cropping pattern,
ground water level, seasonal variation, hours of operation etc.

losses
• 5. Error in Meter Reading
• Proper calibrated meter should be used to
measure electrical energy.
• Defective energy meter should be replaced
immediately.
• The reason for defective meter are burning of
meters, burn out terminal box of meter due to
heavy load, improper C.T.ratio and reducing the
recording, improper testing and calibration of
meters.

losses
• 6. Billing problems
• Faulty and untimely serving bill should be main part of
non-technical Losses.
• Normal complain regarding billing are not receipt of bill;
• late receipt of bill,
• receiving wrong bill,
• wrong meter reading,
• wrong tariff,
• wrong calculations.

UNDERSTANDING SYSTEM LOSSES
• In the context of power system planning and project
engineering, economic aspects must be considered,
compared and assessed for different alternatives and
scenarios, such as the losses resulting from system
operation.
• There are two major types of losses in distribution
systems namely:
• Energy losses (Station and Non-Technical)
• Power losses (Technical, System Losses)

Technical vs. Non-technical Losses Cost

Technical Losses across some African Countries
54
Source: Mr Chris of Worldbank group – ctrimble@worldbank.org; via ESI Africa’s Webinar
Average Technical losses
for 39 out of 54 Countries
in Africa surveyed is
23.36%

Non-Technical Losses across some African Countries
55Source: Mr Chris of World bank group – ctrimble@worldbank.org; via ESI Africa’s Webinar
Average Collection losses for
38 out of 54 Countries in Africa
surveyed is 88.36%

REFERENCES
• A TURNAROUND STORY! ON THE AGGREGATE TECHNICAL AND COMMERCIAL (AT&C) LOSS REDUCTION FROM 53% TO 15% IN
DELHI AREA ACHIEVED IN 8 YEARS BY NDPL (NORTH DELHI POWER LIMITED) By Ajai Nirula .
• Reducing Technical and Non-Technical losses in the Power sector Background Paper for the World Bank Group Energy Sector Strategy,
July 2009
• Non-Technical losses – How do other countries tackle the problem? 22nd AMEU Technical Convention
• Management of electricity distribution network losses by Sohn Assiciates/Imperial college, London, February, 2014.
• Distribution network losses and reduction opportunities from UK DNO’s perspective, 23rd International Conference on Electricity
Distribution Lyon, 15-18 June 2015
• Power Loss Reduction on Primary Distribution Networks by Tap changing, Adejumobi I A and Adebisi O I of Electrical
engineering Department, College of Agriculture, Abeokuta, Nigeria, February, 2012.
• Reduction of power loss of Distribution system by Distribution Network Management, Sarang Pande and Dr. J G Ghodekar of
Department of Electrical Engineering, K.K. Wagh Institute of Engineering & Research, Nashik, India INTERNATIONAL JOURNAL OF MULTIDISCIPLINARYSCIENCES AND ENGINEERING,VOL.3,NO.11,NOVEMBER 2012
• Evaluation of electric energy losses in Southern Governorates of Jordan Distribution Electric System, by Oda Refou, Qais
Alsafasfeh and Mohammed Al-sound of Electrical engineering Department, Tafila Technical University. International Journal of Energy
Engineering 2015, 5(2): 25-33
• http://electrical-engineering-portal.com/total-losses-in-power-distribution-and-transmission-lines-1 and http://electrical-
engineering-portal.com/total-losses-in-power-distribution-and-transmission-lines-2.
• Final report on Power Loss Reduction Technologies of 3 EDCs in Nigeria by DNVKEMA, June, 2013.
• Equipment and systems for outage and emergency management presentation @ Power Africa conference in Nigeria,
October, 2013.
• Reliability Improvement of Distribution System presentation by Prof.Engr. Fertunato C. Lynes, Vice president of Manila
Electric Company, Philliphines @Power Africa Conference, October, 2013.
• NAPTIN Manual on Maintenance of Transformer and SwitchGear, developed in 2016 by Engr A. A. Gwaram and sponsored by
GIZ.
• IEC document “Efficient Electrical Energy Transmission and Distribution” (2007)
• http://blog.schneider-electric.com/energy-management-energy-efficiency/2013/03/25/how-big-are-power-line-losses/
• NAPTIN presentations on Power loss reduction technologies training by DNVKEMA GERS consultant.
• Introduction to Distribution Automation and Impact of Distribution automation presentations by Dr Gers Juan, in NAPTIN
Power loss reduction programme, 2013.
• http://electrical-engineering-portal.com/total-losses-in-power-distribution-and-transmission-lines-1

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