Presentation on ELECTRICITY DISTRIBUTION LOSSES

1
Presentation on ELECTRICITY DISTRIBUTION
LOSSESCONCEPT OF AGGREGATE TECHNICAL AND
COMMERCIAL (ATC) LOSS
R.V. Shahi Former Power Secretary, Govt. of
India Chairman of Energy Infratech Pvt. Ltd.
(November, 2011)
2
CONTENTS

• Anomalies in TD Loss Computation
• Concept of ATC Losses
• Pre-requisites for obtaining baseline ATC
  losses
• Methodology for establishing ATC Losses for
  Project Area
• Sample Calculation for Baseline ATC Losses

3
ANOMALIES IN TD LOSS COMPUTATION

• In Indian Power Sector, TD Losses, as computed
  in the past, over several decades, never
  represented the true picture about losses in the
  system.
• Similar is the situation in a number of
  developing countries.
• The Method Procedures enable manipulations in
  computations. The functionaries (Officers
  Staff) could present a good picture to reflect
  their efficiency, while the ground reality could
  be different.

Contd...
4
ANOMALIES IN TD LOSS COMPUTATION

• In absence of feeder metering separating
  Agriculture Domestic Consumption, substantial
  portion of TD loss, including theft of
  electricity, gets attributed to agricultural
  consumption.
• Also, TD loss was being computed taking into
  account electricity bills issued to consumers as
  accrued income not on actual collection.

Contd...
5
ANOMALIES IN TD LOSS COMPUTATION

• Just by overbilling, one could show a much lower
  than actual loss. Therefore, TD loss figures did
  not capture the major gap between the Billing and
  the Collection, apart from large amount of theft.
• Theft and deliberate manipulations by staff get
  subsumed in excess Billing (Which would obviously
  never get collected)
• To get over this problem, concept of Aggregate
  Technical Commercial (ATC) loss was introduced.

6
CONCEPT OF ATC LOSSES

• TECHNICAL LOSSES
• Factors causing Technical Losses
• Transformation Losses (at various transformation
  levels)
• High I2R losses on distribution lines due to
  inherent resistance and poor power factor in the
  electrical network
• Inadequate Planning Design, irresponsible
  overdrawals by Consumers
• Overloading of existing lines and substation
  equipments
• Absence of upgradation of old lines and
  equipments
• Low HT LT ratio

Contd...
7
CONCEPT OF ATC LOSSES

• TECHNICAL LOSSES
• Factors causing Technical Losses
• Poor repair and maintenance of equipments
• Non-installation of sufficient capacitors
• Requirements for calculating Technical Losses
• 33 kV and below HT network Line Diagrams
• Line Diagrams for each of distribution
  transformers and LT circuits upto poles/feeder
  pillars
• Voltage levels, Power factor and Current loading
  on HT/LT network network equipments
• Line lengths, cross section nature of material,
  network equipments load curve etc

Contd...
8
CONCEPT OF ATC LOSSES

• COMMERCIAL LOSSES
• Factors causing Commercial Losses
• Discrepancy in Meter Reading
• Untraceable consumers
• Stopped/defective meters
• Temporarily disconnected consumers continuing in
  billing solution
• Premises found locked

Contd...
9
CONCEPT OF ATC LOSSES

• COMMERCIAL LOSSES
• Factors causing Commercial Losses
• Metering
• Meter tampering
• Bypassing of meters
• Usage of magnets to slow down the meters
• Tampering of PT circuits
• CT/PT ratios (in case of HT meters)

Contd...
10
CONCEPT OF ATC LOSSES

• COMMERCIAL LOSSES
• Factors causing Commercial Losses
• Theft by direct hooking
• Tapping of LT lines to indulge in theft through
  direct hooking
• Sometimes even drawing an underground cable
  direct from Distribution Transformer

Contd...
11
CONCEPT OF ATC LOSSES

• COMMERCIAL LOSSES
• Collection efficiency
• Utility is not being able to collect the complete
  amount billed by it.
• Absence of Energy Accounting Auditing
• In case of unavailability of arrear figures, the
  collection efficiency figures can be more than
  100.
• Revenue collected shall exclude the arrears.
• In above cases efficiency needs to be restricted
  to 100 and shall be used for computation of ATC
  losses.

12
PRE-REQUISITES FOR OBTAINING BASELINE ATC
LOSSES

• Metering of Energy Input Points of Project Area
• On incoming lines of 33/11 kV sub-stations
  located within project area.
• On 33 kV, 11 kV feeders emanating from
  sub-station located outside project area but
  supplying power to HT/LT consumers located within
  project area.

Contd...
13
PRE-REQUISITES FOR OBTAINING BASELINE ATC
LOSSES

• Ring-fencing of Project area electrical network
• Import/export meters at the boundary of those
  lines that are feeding outside as well as inside
  project area so that import and export of energy
  can be measured for project area. These lines may
  emanate from the sub-stations located within or
  outside project area.
• Import/export meters on the dedicated feeder
  emanating from sub-stations located within
  project area but feeding outside project area.
• Import/export meters on 33/11 kV sub-stations
  LILO/tie lines.

Contd...
14
PRE-REQUISITES FOR OBTAINING BASELINE ATC
LOSSES

• Segregation of Rural Loads within Project Area
• For HT (11kV) feeders, providing power to mixed
  category of consumers including agricultural
  (rural), commercial, domestic etc., within
  project area, utilities may segregate these
  feeders through installation of separate HT
  feeder for such loads.

Contd...
15
PRE-REQUISITES FOR OBTAINING BASELINE ATC
LOSSES

• Billing Revenue Collection System
• Billing system is to be able to provide data like
  sales, revenue billed and collected for entire
  project area.
• The current billing system is designed in a way
  that sale data can be extracted for 11 kV feeder
  or for distribution centers (DCs) as whole.
• Utilities to make provisions to account for sales
  happening outside project area.

Contd...
16
PRE-REQUISITES FOR OBTAINING BASELINE ATC
LOSSES

• Computation of Input Energy
• To install meters at input points of each of
  feeders (66 kV, 33 kV, 11 kV etc.) and read them
  at pre-defined intervals.
• In case of LILO, net input energy to the project
  area of the feeder shall be considered.
• If 66 kV or 33 kV feeder is directly feeding to a
  dedicated consumer and that consumer(s) is within
  project area, input of such feeder shall be
  considered as part of input energy to the project
  area.

17
METHODOLOGY FOR ESTABLISHING ATC LOSSES FOR
PROJECT AREA

• Computation of Sales
• The billing for metered consumers can be done
  through energy recorded by meters and the
  applicable tariff.
• In case of unmetered consumption
• Norms established by respective state regulatory
  commission (SERC) for assessment of unmetered
  consumption.
• In case SERC norms are not defined, a consumption
  of 150 (Units) kWh for each 1 kW of sanctioned
  connected load.
• The assessment is allowed only for limited period
  of time and the utilities are required to
  complete 100 metering within 6 months.

Contd...
18
METHODOLOGY FOR ESTABLISHING ATC LOSSES FOR
PROJECT AREA

• Computation of Billing Efficiency
• Billing Efficiency Total Units Sold (kWh)
• Total Input (kWh)
• Computation of Collection Efficiency
• Collection Efficiency Revenue Collected (in
  Naira)
• Billed Amount (in
  Naira)
• Computation of ATC Losses
• ATC Losses 1-(Billing Efficiency x
  Collection Efficiency)x100

19
COMPUTATION OF ATC LOSSES
20
THANK YOU