Settlement System
under ABT Regime
WHAT IS SETTLEMENT ?
• “ Settlement means Closing the
payment/receipt/adjustment process of
bill for the period under consideration”
• To be FAIR and EQUITABLE
• To RECOVER DUES at the EARLIEST
(Billing Cycle)
• TRANSPERANCY
• Dispute Resolution
• Reconciliation
Capacity charge:
Capacity charge is based on Annual Fixed Charge and will be
related to availability of generating station. Availability means the
readiness of the generating station to deliver ex-bus output expressed
as a percentage of its rated ex-bus output capability.
Energy charge:
Energy charge is related to the scheduled ex-bus energy to be
sent out from the generating station and will be worked out on the
basis of paise per KWh.
AVAILABILITY TARIFF(ABT)
(a)
(b)
(c)
CAPACITY CHARGE
ENERGY CHARGE
ADJUSTMENT FOR DEVIATIONS
(UI CHARGE)
(a)
= a function of Ex-bus MW availability of power plant for the
day
declared before the day starts x SEB’s % share
.
(b)
= MWh for the day as per ex=bus drawl schedule for the SEB
finalized before the day starts x Energy charge rate
=Σ(Actual energy interchange in a 15 min time block –
scheduled energy interchange for the time block) x UI rate
for the time block.
TOTAL PAYMENT FOR THE DAY =
(a) + (b)± ( c)
(c)
SETTLEMENT SYSTEM
For the day: 0000 hrs. to 2400 hrs.
Central Generating Stations
1
2
3
MW
Ex-Bus Capability
(Forecast)
SEB-A’s share
SEB-B’s share
SEB-C’s share
x1
____
x2
___
x3
___
a1
b1
c1
a2
b2
c2
a3
b3
c3
For a particular 15 minute time block
SEB-A’s requisition
SEB-B’s requisition
SEB-C’s requisition
CGS’s schedule
SRLDC/Comml/IEGC/37
a’1
b’1
c’1
___
x1’
a’2
b’2
c’2
___
x2’
a’3
b’3
c’3
___
x3’
SETTLEMENT SYSTEM
Total capacity charge payable to CGS-1 for the day
= x1 * capacity charge rate of CGS-1
Total Energy charge payable to CGS-1 for the day
= x1’ * Energy charge rate of CGS-1
4
Total capacity charge payable by SEB-A for the day
= a1 * capacity charge rate of CGS-1
+ a2 *
-doCGS-2
+ a3 *
-doCGS-3
Total Energy charge payable by SEB-A for the day
= (a1’) * Energy charge rate of CGS-1
( 4 )
+ (a2’) *
-doCGS-2
( 4 )
+ (a3’) *
-doCGS-3
( 4 )
All capacity charge and Energy charge payments to be made by SEBs
directly to CGS.
SRLDC/Comml/IEGC/38
SETTLEMENT SYSTEM
Actual (metered) injection of CGS-1 in the time block = X1 MWh.
Excess injection = (X1 – x1’ ) MWh.
4
Amount payable to CGS-1 for this =(X1-x1’) * pool price for the block.
4
SEB-A’s scheduled drawl for time block = a1’+a2’+a3’ = a’ MW (ex-CGS Bus)
SEB-A’s NET drawal schedule = (a’ – Notional Transm. Loss) MW
= (a’ – Notional Transm. Loss) = A’ MWH
4
Actual (metered) net drawal of SEB-A during time block = A MWH
Excess drawal by SEB-A = (A-A’) MWh.
Amount payable by SEB-A for this = (A-A’) * pool price for the block.
All above payments for deviations from schedules to be routed through a
pool A/C operated by RLDC
SRLDC/Comml/IEGC/39
AVAILABILITY
• Availability in relation to a generating
station for any period means the average
of the DCs for all the days during that
period expressed as a percentage of the
installed capacity of generating station
minus normative auxiliary consumption in
MW and shall be computed as per the
following formula:
Present Definition Capacity
charges
N
DCi/ {NxICx(100-Auxn) }%
10000
i=1
% Availability =
Where DCi = Average Declared Capacity for i th day of the period in MW
N = Total no. of days during the period
Auxn = Normative Auxiliary Consumption as % of gross Gen.
IC= installed capacity in MW
% Availability forms the basis for calculations
N
PLF =
SGi/ {NxICx(100-Auxn) }%
10000
i=1
Recovery of Annual fixed charges
100% recovery
- Pro-rata reduction
if % Availability
>=Target Availability
if %Avb<T.Avb.
- Target Availability For Fixed charges recovery
- Target PLF for incentive
-Both to be Notified by CERC
-Financial Year forms the basis for calculations
ISGS
RSTPS
NLC
Target Availabilty
80%
75%
Target PLF
80%
75%
Monthly Capacity charges receivable by
an ISGS:
1 st Month = (1xACC1)12
2 nd Month = (2xACC2-1ACC1)12
….
….
12 th month = (12xACC12-11ACC11)12
where ACC1,ACC2…….ACC12 = Annual capacity charges corresponding to the
cum. Availability up to the corresponding month.
Monthly Capacity charges payable by a
beneficiary :
1 st Month = (1xACC1xWB1)12
2 nd Month = (2xACC2xWB2-1ACC1xWB1)12
….
….
12 th month = (12xACC12xWB12-11xACC11xWB11)12
where WB1,WB2…..WB12 = Weighted average % share up to the corresponding
month.
Name Of
ISGS
Aux.
Consumption
RSTPS
7.93%
Variable
Charges
(Ps)
98
NLC II/1
10.00%
75
NLC II/2
10.00%
100
NLC TPS 1
(EXP)
9.50%
131
TALCHERSTAGE II
7.5%
74
Energy charges
The Energy Charges Payable by beneficiary to the
ISGS =
Variable Charge of ISGS X
Requisition of beneficiary from The
ISGS
The Energy Charges Receivable by ISGS from
beneficiaries =
Variable Charge of ISGS X
Despatch schedule of ISGS
Incentive as per existing norms
• Flat rate of 25ps/u
• For ex-bus Schedule Energy in Excess of
ex-bus energy corresponding to Target
PLF
Settlement Systems*
On weekly basis :
For seven day period ending on penultimate Sunday
•RLDC to furnish Scheduling & Metering data to REB
• Sectt. by Thursday noon
•REB Sectt. to issue Weekly UI a/c by Tuesday
•Pool a/c operated by RLDC
•Settlement for UI on weekly basis
•All accounts open for 20 days
SRLDC/Comml/IEGC/34
Settlement System contd..
• On monthly basis :
• REB to issue REA specifying % Avb, %
Net Entitlement, % Energy charges, Wt.
Avg. Ent. for Tr. Ch. etc.
• Capacity and Energy Charges, Incentive
etc.
• –billed directly by ISGS based on REA
issued by REB
WEEKLY ENERGY ACCOUNTING:
WEEKLY CYCLE
ACTIVITIES
MONDAY MORNING
THURSDAY NOON
REB
Tues day
: 00 HRS OF EACH MONDAY TO 24 HRS;
OF THE THE FOLLOWING SUNDAY
: SEM DATA DOWNLOADED TO DCD
: DCD DATA LOADED TO A LOCAL PC
: DATA SENT TO RLDC via E-MAIL
(LATEST TUESDAY MORNING )
: RLDC CONVEYS PROCESSED DATA TO
: WEEKLY UI a/c & Reactive charges
issued BY REB
BILLING
Cap. Charge
: BILLED MONTHLY based on DAILY
DC BY ISGS
ENERGY CHARGE
: BILLED MONTHLY based on DAILY
DRAWL SCHEDULES ISSUED BY RLDC
UI a/c
Paid/Disbursed as per UI a/c issued by REB
REACTIVE a/c
Unscheduled Interchanges (UI)
Variations in actual generation/drawal and scheduled generation
/drawal are accounted through UI. This is a frequency linked charge
which is worked out for each 15 minute time block.
Charges for all UI transaction, based on average frequency have
following rate of paise per KWh from 01.01.03 up to 31.03.04.
UI rate (Paise per KWh)
Average Frequency of time block
50.5 Hz. and above
0.0
Below 50.5 Hz. and upto 50.48 Hz.
5.6
Below 49.04 Hz. and upto 49.02 Hz.
414.4
Below 49.02 Hz.
420.0
Between 50.5 Hz. and 49.02 Hz. Linear in 0.02 Hz. step
UI rate w.e.f 01.04.04 to 30.09.04
UI rate (Paise per KWh)
Average Frequency of time block
50.5 Hz. and above
0.0
Below 50.5 Hz. and upto 50.48 Hz.
8.0
Below 49.04 Hz. and upto 49.02 Hz.
592.0
Below 49.02 Hz.
600.0
Between 50.5 Hz. and 49.02 Hz. Linear in 0.02 Hz.
step
• UI rate w.e.f 01.10.04
UI rate (Paise per KWh)
Average Frequency of time block (Hz,)
Below
Not below
----50.50
0.0
50.50
50.48
6.0
50.48
50.46
12.0
------------------------49.84
49.82
204.0
49.82
49.80
210.0
49.80
49.78
219.0
49.78
49.76
228.0
------------------------49.04
49.02
561.0
49.02
----570.0
(Each 0.02 Hz. Step is equivalent to 6.0 paise/kWh in the 50.549.8 Hz. Frequency range and to 9.0 paise/kWh in the 49.8-49.0
Hz. Frequency range).
Under drawl by SEB-A
Over Gen. By ISGS-1
UI import from IR-1
Regional Pool
System
frequency
Under gen. By ISGS-2
UI Export to IR-2
Over drawl by SEB-B
No one to one correspondence
Energy transactions of UI from/to Pool
UI
Rate
Operation of Pool
Separate Pool a/cs operated by RLDCs on behalf of REBs for UI,
IRE and Reactive charges
Payable by SEB-B
Payable by IR-2
at its UI rate
Payable by ISGS-2
Regional Pool
Receivable by ISGS-1
Receivable by SEB-A
(up to DC)
No one to one correspondence
Receivable by IR-1
at its UI rate
No cross adjustments allowed between the constituents
Where do SEMs come into picture?
• Only measuring Deviations from Schedule
i.e. UI
• To measure 15 min block-wise Energy
and Frequency
Issues concerned :
-Specifications
-Location criterion
-Main/Check/Standby philosophy
Metering Philosophy under ABT regime
NTPC Station
Aux.
B
A
C
Other than NTPC Station
Aux.
Aux.
D
E
ISGS -I
F
F'
G
H
L
M
ISTS
J
J'
M2
M1
C1
C2
S1
K
K'
ISGS -II
S2
SEB-A
T
V
U
ISTS
S
W
N
O
P
SEB-B
R
Q
SEB-B
SEB-A
X
Main Meter
Y
Standby Meter
Check Meter
SEB-A
ISTS
ISGS-I injection
Main = (F+G+H+J+K)
Check=(F'+L+M+J'+K')
Standby = (A+B+C+D+E)
ISGS-II injection
Main = (M1+M2)
Check=(C1+C2)
Standby = (S1+S2)
SEB-A drawal
Main = (G+H+N+O+Y)
Standby = (L+M+Q+R+X)
SEB-B drawal
Main = (T+U+X)
Standby = (V+W+Y)
Points for Energy Accounting
Injection by NTPC Generating Stations :
Main &check meters on Outgoing feeders
Standby meters on HV side of GT/TT
Injection by other Generating Stations :
Main &check meters on HV side of GT/TT
Standby meters on Outgoing feeders
Drawl by SEBs
Main -HV side of ICTs at GS and CTU S/S,
Receiving end of Lines directly connected to ISGS
Respective ends of Lines connected to other SEBs
Standby – LV/ Tertiary side of ICTs
Other end of lines connected to other SEBs
Special Energy Meter Features
• STATIC TYPE
• COMPOSITE METER
• HIGHEST ACCURACY IN POWER INDUSTRY
• 3 PHASE-4 WIRE CONNECTIONS / MEASUREMENT
• DIRECT MEASUREMENT AS PER CT/PT SECONDARY
QUANTITIES
- 110V PH TO PH/63.51 V PH-N
- 1 AMP OR 5 AMP
- VA BURDEN NOT >10 ON ANY OF THE PHASES
• WORKS ON REAL TIME CLOCK
• NO CALIBRATION REQUIRED
• TIME ADJUSTMENT FACILITY
• HIGH SECURITY OF DATA STORAGE
Raw data
WEEK FROM 0000 HRS OF 06-01-01 TO 0837 HRS OF 15-01-01
NP-0185-A
91858.5
99968.5
39195.5
06-01-01
00 51
+21.57 48
04 19
+20.61 23
08 00
+24.95 00
12 71
+24.38 52
16 00
+23.37 00
20 00
+25.75 00
NP-0185-A
94117.2
+21.68 50
+20.80 19
+24.95 00
+23.98 30
+23.52 00
+25.32 00
99968.5
+21.71
+21.05
+25.09
+23.81
+22.87
+25.40
40313.5
49
00
00
13
00
00
+21.33
+21.35
+24.38
+24.03
+21.66
+25.37
07-01-01
….
…
…
…
…
…
00 59
+20.94 54
04 33
+20.05 38
08 00
+22.99 06
12 85
+20.93 51
16 07
+20.14 01
20 05
+23.62 08
NP-0185-A
96172.2
+21.01 59
+20.17 37
+23.10 00
+20.65 21
+20.53 00
+23.23 16
99968.5
+20.79
+20.49
+22.81
+20.79
+20.72
+23.25
41236.9
58
28
00
00
00
27
+21.05
+20.90
+22.94
+19.89
+20.66
+23.40
08-01-01
…
…
…
…
…
…
Special Energy Meter Various Checks
CHECKS for DATA VALIDATION :
•
•
•
•
•
•
NOMINAL VOLTAGE CHECK
FREQUENCY
TIME CORRECTION
WATTHOUR CHECK
PREVIOUS WEEK DATA
ALGEBRAIC SUM
Special Energy Meter Data Computing
• RAW DATA IN WHr
• MWhr = RAW DATA x CT RATIO x PT
RATIO
• PAIR CHECK DONE
FOR MAIN/
CHECK/ STANDBY/ FICTMETERS ( ex. :
for both sides of ICTs, Lines, GT side &
Line side at ISGS.
Reactive Energy Accounting
Reactive Energy is measured
when system voltage is
> 103% of Nominal Voltage
< 97% of Nominal Voltage
Loss computations
15 min block-wise % loss =
(Sum of all Injections from ISGS + net IR imports) (Sum of Drawals by all beneficiaries from Central Grid)
X
(Sum of all Injections from ISGS + net IR imports)
100
Use of Notional Loss in scheduling
• % Average loss (15 min. blockwise)
aggregated over the last week will be used
in Scheduling Process for the next week.
(for arriving at the ex-periphery Drawal
Schedules of Beneficiaries)
0.5%
REDUCTION MEANS MORE THAN 100 CR ANNUAL SAVINGS
TYPICAL %AVERAGE LOSS FIGURES
FOR CENTRAL GRID IN SR
Loss for the week
From
Loss %
To
Week applied for
From
To
16-Sep-02
22-Sep-02
4.83
30-Sep-02
6-Oct-02
6-Jan-03
12-Jan-03
3.9
20-Jan-03
26-Jan-03
20-Oct-03
26-Oct-03
3.38
3-Nov-03
9-Nov-03
19-Jan-04
25-Jan-04
3.92
2-Feb-04
8-Feb-04
24-May-04
30-May-04
2.55
7-Jun-04
13-Jun-04
9-Aug-04
15-Aug-04
2.54
23-Aug-04
29-Aug-04
17-Jan-05
23-Jan-05
3.25
31-Jan-05
6-Feb-05
7-Feb-05
13-Feb-05
3.04
21-Feb-05
27-Feb-05
30-May-05
5-Jun-05
2.95
13-Jun-05
19-Jun-05
27-Jun-05
3-Jul-05
3.49
11-Jul-05
17-Jul-05
11-Jul-05
17-Jul-05
3.73
25-Jul-05
31-Jul-05
25-Jul-05
31-Jul-05
3.53
8-Aug-05
14-Aug-05
1-Aug-05
7-Aug-05
3.3
15-Aug-05
21-Aug-05
8-Aug-05
14-Aug-05
2.92
22-Aug-05
28-Aug-05
OTHER REGIONS
%Average losses
In other Regions :
NR 3.5 to 4.5
ER
3.0 to 3.5
WR
5.0 to 6.0
%loss for different weeks from 2003- 2005
5.0
4.5
2005-06
2003-04
4.0
2004-05
%loss
3.5
3.0
2.5
2.0
1.5
1.0
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51
Week No.
REACTIVE ENERGY CHARGE :
PAYABLE FOR :
1.
2.
VAR DRAWALS AT VOLTAGES BELOW 97%
VAR INJECTION AT VOLTAGES ABOVE 103%
RECEIVABLE FOR:
1.
2.
VAR INJECTION AT VOLTAGES BELOW 97%
VAR DRAWAL AT VOLTAGES ABOVE 103%
APPLIED FOR VAR EXCHANGES BETWEEN :
A)
BENEFICIARY SYSTEM AND ISTS
- THROUGH A POOL ACCOUNT
B)
TWO BENEFICIARY SYSTEMS ON
INTER-STATE TIES
- BY THEMSELVES
RATE:
@ Rs. 51.05/MVArh (for 205-06)
Basic Rate : 4 paise/kvArh ( for the year 2000-01 )
5% ESCALATION PER YEAR
Issues in Reactive Energy charges
• Deficit in pool (SR & ER)
-due to continuous High voltages in SR
Surplus in Pool (NR &WR)
Utilization of Accruals
Disputes in payments between Beneficiaries
for Reactive charges in Inter-state Lines
SOUTHERN REGIONAL ELECTRICITY BOARD
ABT based U.I. Account
FOR A TYPICAL WEEK
NNOTE:
MAPS & KGS not covered under ABT; hence UI reduced to zero,
under all conditions
. IR Exchanges:
- Metering points – For WR it is Chandrapur South Bus.
- For ER it is Gazuwaka East Bus & Talcher stage
I&II interconnecting bus.
1.
ii)
UI for IR exchanges with ER has been calculated at
ER frequency.
iii) UI charges with WR and ER has been taken as first charge,
as per decision taken in Special Committee meeting held on
17.12.2002.
A.
ABSTRACT OF UNSCHEDULED INTERCHANGES
( UI figures in Rs. Lakhs)
Utilities
UI Payable
Utilities
UI Receivable
KPTCL
720.47741
TNEB
641.48459
KSEB
457.19673
APTRANSCO
269.73260
PONDY
124.38710
ER
188.40533
NLC_II_2
14.72798
RSTPS
84.30154
NLC_II_1
13.81846
GOA
10.67606
TALCHER_II
TOTAL
2.36108
1332.96876
NLC_I_EXP
2.25996
WR
1.32476
TOTAL
1198.18484
ABSTRACT OF UNSCHEDULED INTERCHANGES (restricting to the lesser
of the two as per the 126th SRE Board decision).
(UI figures in Rs.
Lakhs)
Utilities
UI Payable
Utilities
UI Receivable
A.
KPTCL
647.62591
TNEB
641.48459
KSEB
410.96701
APTRANSCO
269.73260
PONDY
111.80962
ER
188.40533
NLC_II_2
13.23876
RSTPS
84.30154
NLC_II_1
12.42120
GOA
10.67606
TALCHER_II
TOTAL
2.12234
1198.18484
NLC_I_EXP
2.25996
WR
1.32476
TOTAL
1198.18484
A.REACTIVE ENERGY CHARGES WITH THE POOL :
( Amount in receiva
Rupees)
payable
ble
Beneficiariesto Pool Beneficiaries from
APTRANSCO
516417
KPTCL
1998690
KSEB
231733
TNEB
3185840
B.NET REACTIVE ENERGY CHARGES BETWEEN BENEFICIERIES:
s per decision in the 132nd meeting of SRE Board)
BY
BENEFICIERY
APTRANSCO
KPTCL
KSEB
TNEB
PONDY
GOA
FROM
BENEFICIERY
KPTCL
TNEB
PONDY
APTRANSCO
KSEB
TNEB
GOA
KPTCL
TNEB
APTRANSCO
KPTCL
KSEB
APTRANSCO
KPTCL
AMOUNT
RECEIVABLE
in Rupees 0
0
0
0
4,853
0
0
0
235,924
28
0
0
11,410
0