1. Energy Accounting and Need for Special Energy Meters under ABT Regime

2. Energy Account The energy accounting closely monitors the energy flow within and beyond the organisation, and also to help identify areas where system efficiencies can be improved. It provides reports on the energy losses at each level of the transmission and distribution network, and within specific geographical regions. It also helps identify long- and short-term strategic management trends. To be FAIR and EQUITABLE To RECOVER DUES at the EARLIEST (Billing Cycle) TRANSPERANCY Dispute Resolution Reconciliation

3. 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.

4. AVAILABILITY TARIFF(ABT) (a)CAPACITY CHARGE (b)ENERGY CHARGE (c)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 (c)=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)

5. SETTLEMENT SYSTEM For the day: 0000 hrs. to 2400 hrs. Central Generating Stations 1 23 Ex-Bus Capability x1x2x3 (Forecast) __________ SEB-A’s sharea1a2a3 SEB-B’s shareb1b2b3 SEB-C’s sharec1c2c3 For a particular 15 minute time block SEB-A’s requisition a’1a’2a’3 SEB-B’s requisition b’1b’2b’3 SEB-C’s requisition c’1c’2c’3 _________ CGS’s schedule x1’x2’x3’ MW SRLDC/Comml/IEGC/37

6. 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 = x 1 ’ * Energy charge rate of CGS-1 4 Total capacity charge payable by SEB-A for the day = a 1 * capacity charge rate of CGS-1 + a 2 * -do- CGS-2 + a 3 * -do- CGS-3 Total Energy charge payable by SEB-A for the day = (a 1 ’) * Energy charge rate of CGS-1 ( 4 ) + (a 2 ’) * -do- CGS-2 ( 4 ) + (a 3 ’) * -do- CGS-3 ( 4 ) All capacity charge and Energy charge payments to be made by SEBs directly to CGS. SRLDC/Comml/IEGC/38

7. SETTLEMENT SYSTEM Actual (metered) injection of CGS-1 in the time block = X 1 MWh. Excess injection = (X1 – x 1 ’ ) 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 = a 1 ’+a 2 ’+a 3 ’ = 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

8. 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:

9. Present Definition Capacity charges % Availability = i=1 N DC i / {NxICx(100-Aux n ) }% 10000 Where DC i = Average Declared Capacity for i th day of the period in MW N = Total no. of days during the period Aux n = Normative Auxiliary Consumption as % of gross Gen. IC= installed capacity in MW % Availability forms the basis for calculations i=1 N SG i / {NxICx(100-Aux n ) }% 10000 PLF =

10. Recovery of Annual fixed charges 100% recovery if % Availability >=Target Availability - Pro-rata reduction 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 Target Availabilty Target PLF RSTPS 80% 80% NLC 75% 75%

11. 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.

12. Name Of ISGS Aux. Consumption Variable Charges (Ps) RSTPS7.93%98 NLC II/110.00%75 NLC II/210.00%100 NLC TPS 1 (EXP) 9.50%131 TALCHER- STAGE II 7.5%74

13. 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

14. Flat rate of 25ps/u For ex-bus Schedule Energy in Excess of ex-bus energy corresponding to Target PLF Incentive as per existing norms

15. 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

16. 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

17. WEEKLY ENERGY ACCOUNTING: WEEKLY CYCLE: 00 HRS OF EACH MONDAY TO 24 HRS; OF THE THE FOLLOWING SUNDAY ACTIVITIES MONDAY MORNING: SEM DATA DOWNLOADED TO DCD : DCD DATA LOADED TO A LOCAL PC : DATA SENT TO RLDC via E-MAIL (LATEST TUESDAY MORNING ) THURSDAY NOON: RLDC CONVEYS PROCESSED DATA TO REB Tues day: 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

18. 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 Unscheduled Interchanges (UI)

19. Present UI rate UI rate (Paise per KWh) Average Frequency of time block (Hz,) BelowNot below -----50.500.0 50.5050.486.0 50.4850.4612.0 --------------- --------------- 49.84 49.82 204.0 49.82 49.80 210.0 49.8049.78219.0 49.7849.76228.0 --------------- 49.5249.50345.0 49.5049.48329.0 --------------- 49.0449.02729.0 49.02-----745 (Each 0.02 Hz. Step is equivalent to 6.0 paise/kWh in the 50.5-49.8 Hz. Frequency range and to 9.0 paise/kWh in the 49.8-49.5 Hz. Frequency range and to 16.0 paise/kWh in the 49.5-49.0 Hz. Frequency range).

20. Energy transactions of UI from/to Pool Over Gen. By ISGS-1 Under drawl by SEB-A UI import from IR-1 Under gen. By ISGS-2 No one to one correspondence System frequency UI Rate Regional Pool Over drawl by SEB-B UI Export to IR-2

21. Operation of Pool Separate Pool a/cs operated by RLDCs on behalf of REBs for UI, IRE and Reactive charges Regional Pool Payable by ISGS-2 Payable by SEB-B Payable by IR-2 at its UI rate Receivable by ISGS-1 (up to DC) Receivable by SEB-A Receivable by IR-1 at its UI rate No one to one correspondence No cross adjustments allowed between the constituents

22. 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

23. ISTS ISGS -II SEB-B drawal Main = (T+U+X) Standby = (V+W+Y ) SEB-A drawal Main = (G+H+N+O+Y) Standby = (L+M+Q+R+X) Metering Philosophy under ABT regime Other than NTPC Station ISGS-I injection Main = (F+G+H+J+K) Check=(F'+L+M+J'+K') Standby = (A+B+C+D+E)

24. 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

25. 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

26. 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 +21.68 50 +21.71 49 +21.33 …. 04 19 +20.61 23 +20.80 19 +21.05 00 +21.35 … 08 00 +24.95 00 +24.95 00 +25.09 00 +24.38 … 12 71 +24.38 52 +23.98 30 +23.81 13 +24.03 … 16 00 +23.37 00 +23.52 00 +22.87 00 +21.66 … 20 00 +25.75 00 +25.32 00 +25.40 00 +25.37 … NP-0185-A 94117.2 99968.5 40313.5 07-01-01 00 59 +20.94 54 +21.01 59 +20.79 58 +21.05 … 04 33 +20.05 38 +20.17 37 +20.49 28 +20.90 … 08 00 +22.99 06 +23.10 00 +22.81 00 +22.94 … 12 85 +20.93 51 +20.65 21 +20.79 00 +19.89 … 16 07 +20.14 01 +20.53 00 +20.72 00 +20.66 … 20 05 +23.62 08 +23.23 16 +23.25 27 +23.40 … NP-0185-A 96172.2 99968.5 41236.9 08-01-01

27. Special Energy Meter Various Checks CHECKS for DATA VALIDATION : NOMINAL VOLTAGE CHECK FREQUENCY TIME CORRECTION WATTHOUR CHECK PREVIOUS WEEK DATA ALGEBRAIC SUM

28. 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. Special Energy Meter Data Computing

29. Reactive Energy Accounting Reactive Energy is measured when system voltage is > 103% of Nominal Voltage < 97% of Nominal Voltage

30. Loss computations 15 min block-wise % loss = (Sum of all Injections from ISGS + net IR imports) X 100 (Sum of all Injections from ISGS + net IR imports) - (Sum of Drawals by all beneficiaries from Central Grid)

31. 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 0.5% REDUCTION MEANS MORE THAN 100 CR ANNUAL SAVINGS

32. Loss for the weekLoss %Week applied for FromTo FromTo 16-Sep-0222-Sep-02 4.83 30-Sep-026-Oct-02 6-Jan-0312-Jan-03 3.9 20-Jan-0326-Jan-03 20-Oct-0326-Oct-03 3.38 3-Nov-039-Nov-03 19-Jan-0425-Jan-04 3.92 2-Feb-048-Feb-04 24-May-0430-May-04 2.55 7-Jun-0413-Jun-04 9-Aug-0415-Aug-04 2.54 23-Aug-0429-Aug-04 17-Jan-0523-Jan-05 3.25 31-Jan-056-Feb-05 7-Feb-0513-Feb-05 3.04 21-Feb-0527-Feb-05 30-May-055-Jun-05 2.95 13-Jun-0519-Jun-05 27-Jun-053-Jul-05 3.49 11-Jul-0517-Jul-05 11-Jul-0517-Jul-05 3.73 25-Jul-0531-Jul-05 25-Jul-0531-Jul-05 3.53 8-Aug-0514-Aug-05 1-Aug-057-Aug-05 3.3 15-Aug-0521-Aug-05 8-Aug-0514-Aug-05 2.92 22-Aug-0528-Aug-05 TYPICAL %AVERAGE LOSS FIGURES FOR CENTRAL GRID IN SR %Average losses In other Regions : NR 3.5 to 4.5 ER 3.0 to 3.5 WR 5.0 to 6.0 OTHER REGIONS

34. REACTIVE ENERGY CHARGE : PAYABLE FOR : 1.VAR DRAWALS AT VOLTAGES BELOW 97% 2.VAR INJECTION AT VOLTAGES ABOVE 103% RECEIVABLE FOR: 1.VAR INJECTION AT VOLTAGES BELOW 97% 2.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

35. 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

36. SOUTHERN REGIONAL ELECTRICITY BOARD ABT based U.I. Account FOR A TYPICAL WEEK NNOTE : 1. 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. 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.

37. A. ABSTRACT OF UNSCHEDULED INTERCHANGES ( UI figures in Rs. Lakhs) UtilitiesUI PayableUtilitiesUI Receivable KPTCL720.47741TNEB641.48459 KSEB457.19673APTRANSCO269.73260 PONDY124.38710ER188.40533 NLC_II_214.72798RSTPS84.30154 NLC_II_113.81846GOA10.67606 TALCHER_II2.36108NLC_I_EXP2.25996 WR1.32476 TOTAL1332.96876TOTAL1198.18484

38. A. ABSTRACT OF UNSCHEDULED INTERCHANGES (restricting to the lesser of the two as per the 126 th SRE Board decision). (UI figures in Rs. Lakhs) UtilitiesUI PayableUtilitiesUI Receivable KPTCL647.62591TNEB641.48459 KSEB410.96701APTRANSCO269.73260 PONDY111.80962ER188.40533 NLC_II_213.23876RSTPS84.30154 NLC_II_112.42120GOA10.67606 TALCHER_II2.12234NLC_I_EXP2.25996 WR1.32476 TOTAL1198.18484TOTAL1198.18484