Sikkim
Allahabad
132 kV Rihand - Sonenagar
132 kv Rihand-Garwah
JHARKHAND
W.BENGAL
Raipur
220 KV Korba (MP) – Budhipadar
(Orissa)
Rourkella
Talcher
ORISSA
220 kV Balimela (Orissa) -Upper
Sileru
Kolar
Vizag
B’nggon
220 kV Birpara-Salakti D/C line
1999
BIHAR
132 kV Sahupuri-Karmanasa S/C 220 kV Dehri -Sahupuri
Tala
Savings of ER Constituents Due to Export
YEAR
ISGS Thermal
GEN
(MU)
EXPORT
(MU)
TOTAL
SAVING
(RS. CR)
1995-96
9584
854
69
1996-97
10628
652
75
1997-98
13585
2389
309
1998-99
14063
3438
461
1999-00
16381
5931
735
2000-01
18228
6773
755
2001-02
18279
8721
943
2002-03
20460
9382
961
National Grid
CTU_NORTH
RLDC
CTU_NE
CTU – INTER REGION
RLDC
CTU_EAST
CTU_WEST
RLDC
RLDC
STU
STU
RLDC
STU
NLDC
CTU_SOUTH
ERLDC:POWERGRID
BULK POWER
TRANSACTION
W.R
C.S.GENERATORS
N.R
SR
STATE SECTOR
GENERATORS
NER
STATE
SYSTEMS
Operating Frequency
49 to 50.5 Hz
Frequency band for safe operation of
Steam Turbine as
recommended in IEGC
Pre ABT Settlement system
• The payment to Central Generating Station by a
constituent - proportion to total energy
– Recommendation of K.P.Rao
drawal
Committee Report.
• Both Fixed and Variable charge was payable as per
energy drawal
• Based on Monthly Regional Energy Account- REA
• Conventional Meter Readings
• Fixed cost recoverable with deemed generation
( generation not made available)
•Incentive
payable
after
accounting
for
deemed
generation
Although a two part tariff- Single part for
constituent
Inadequacies
• Non-utilization of Utilities’ Surplus Power
– No incentive for Maximization of own/ IPP/captive generation within a State as the
cost of power paid is based on pooled rate of ISGS stations.
– No effective commercial mechanism for pricing deviations from schedule.
• Dumping of surplus power at High Freq
– Forced Backing down/ Reserve Shut down
– Deemed generation for backing down
• Non-utilization of embedded IPP/Licensee surplus Power.
– Administrative problems and no commercial arrangements for utilization of this
power. Any surplus remains unutilized.
• Non-utilization of Pumped Storage Scheme
– No commercial mechanism to draw cheap off peak power for pumping. Bhira
PSS/Kadamkadai is not being utilized in the pumping mode.
Contd..
• Inability to Despatch Generation according to
Grid requirement.
– Generation of Licensees cannot be despatched as per Grid requirements due to
commercial problems.
• Curtailment of Bilateral Transactions due to
Grid Indiscipline.
– Overdrawing State(s) deliberately increase drawls and cause frequency to dip
below 48.5 Hz so that inter-regional transactions are terminated.
• Absence of Merit Order Operation
– As payments are based on drawls and not on shares/schedules, fixed
cost are not perceived as sunk costs.
Inherent Disadvantage
• No incentives for generators /utilities to respond to
dispatch orders for issues like frequency control
– No Incentive for helping the grid
– No disincentive for hurting the grid
• No signal to generators to match availability with
system needs
• Did not promote Grid Discipline
• No signal for trading of power.
Overall economy was lost.
EFFECT
• Backing down of cheaper CS generation
– Caused high per unit cost
• Dumping of energy by other utility at high
frequency/off peak hours– additional
fixed
cost
generation & transmission.
• More payment Liability
- Even when helped the grid
liability
for
Ultimate Effect
• Grid Indiscipline• Low Frequency during peak
• High Frequency during off peak
• Control Instructions
• Subjective decisions
• Not based on overall economy
• Perpetual Operational & Commercial
Dispute amongst Utilities/Central
Generators
• Poor Supply quality to
consumers/industries
• Damage to equipments
• Shifting of Industries/Investments
Why ABT?
•Promote competition, efficiency
Merit order dispatch
and economy-
•Competitive market based system
•Possibility of trading on a non-firm basisselling of capacity entitlement
•Facilitating Grid discipline- Incentive and
disincentive for deviation
Capacity Ch. + Energy Ch.  UI
A
+
B
 C
TOPICS DEALT IN THE ORDER
• TARGET AVAILABILITY
• CRITERIA FOR INCENTIVE
• PROCEDURE FOR PREVENTION OF GAMING
• PROLONGED OUTAGES
• UI CHARGES AND FREQUENCY VARIATION
• SETTLEMENT OF UI ACCOUNT
• TREATMENT OF UNALLOCATED CAPACITIES
Availablity Based Tariff (ABT)
•
•
•
Links commercial mechanism & Grid Operation
Promotes grid operation
ABT Structure – 3 parts of tariffs
A. Capacity charges
– Proportionate to entitlements (not actual drawals)
– Full recovery at target availability (not PLF)
– Incentives linked to Availability (80%) and PLF (77%)
– Incentives half of per KWh fixed charges at target availability /
capped at 21 p/u
B. Energy charges
– Payable for schedules (not as per actual drawals)
C. Unscheduled Interchange
– Payable for deviations from schedules
– Linked to average frequency for 15 minute time block (graph
enclosed)
Central Govt.
CERC
CTU
REB
RLDC
CEA
State Govt
SEB/STU
SERC
SLDC
ISTS
&
ISGS
X=
L- G
.
Control Area