Availability Based Tariff (ABT)in

Northern Region

CONTROL AREAS

CS - 1 CS - 3

CS - 2

SEB-B SEB-C

STATE

DISTR - A DISTR - C

DISTR - B

SEB's GRIDSLDCCOORDINATES/DIRECTS

SEB-A

COORDINATES/RLDC

REGIONAL GRID

IPP

STATEGENR.

SHARECENTRAL

G1 G2

SERC

SLDCSEB/STUState Govt.

RLDC

REB

CTU

CERC

Central Govt. CEA

ISTS

ISGS

Load

L1 L2

Intra State System

IEGC to Operate on the periphery

X= - GL G

What is Availability Based Tariff (ABT)?What is Availability Based Tariff (ABT)?

Day-Ahead SchedulingDay-Ahead Scheduling

Real time operationReal time operation

Regional Energy Accounting (REA)Regional Energy Accounting (REA)

FAQs on ABTFAQs on ABT

Availability Based Tariff (ABT) is Availability Based Tariff (ABT) is applicable at the regional grid applicable at the regional grid level only between the ISGS level only between the ISGS stations and the SEBs/STUs.stations and the SEBs/STUs.

However a similar scheme However a similar scheme between the SEBs/STUs and the between the SEBs/STUs and the GENCOs and DISCOMs within GENCOs and DISCOMs within the state is desirable.the state is desirable.

Components of inter-utility tariffComponents of inter-utility tariff(Pre – ABT Mechanism)(Pre – ABT Mechanism)

Fixed chargesFixed charges Interest on loansInterest on loans DepreciationDepreciation O & M chargesO & M charges Return on equityReturn on equity Interest on Working CapitalInterest on Working Capital

Energy charges (fuel cost)Energy charges (fuel cost) IncentivesIncentives Surcharge & other leviesSurcharge & other levies No charge for reactive energyNo charge for reactive energy

TENTATIVE COST FOR NTPC THERMAL STATIONS FOR THE MONTH OF DEC 2003TENTATIVE COST FOR NTPC THERMAL STATIONS FOR THE MONTH OF DEC 2003

StationStationFixed Cost Fixed Cost Rs. Cr/yrRs. Cr/yr

(1)(1)

Average Average Fixed Cost Fixed Cost Rs. Cr/dayRs. Cr/day

(2)(2)

Average Average Fixed Cost Fixed Cost P / KWhP / KWh

(3)(3)

Variable Variable Base Cost Base Cost P / KWhP / KWh

(4)(4)

Variable Variable FPA FPA P / KWhP / KWh

(5)(5)

Total Total Variable Variable Base Cost Base Cost P / KWh P / KWh

(6)(6)

Composite Composite Cost Cost P / KWhP / KWh

(3) + (6)(3) + (6)

SingrauliSingrauli 364.59364.59 0.9960.996 28.2728.27 67.9867.98 7.867.86 75.8475.84 104.11104.11

RihandRihand 478.74478.74 1.3301.330 65.8365.83 106.03106.03 44.7044.70 78.9978.99 137.41137.41

Unchahar – IUnchahar – I 195.91195.91 0.5350.535 73.3573.35 55.8355.83 6.746.74 112.77112.77 186.12186.12

Anta GPS*Anta GPS* 92.9292.92 0.2580.258 47.1347.13 60.5560.55 84.1184.11 144.66144.66 139.47139.47

Auraiya GPS*Auraiya GPS* 160.20160.20 0.4450.445 42.1742.17 61.9261.92 92.8892.88 154.80154.80 169.73169.73

DadriGPS G)DadriGPS G) 210.96210.96 0.5760.576 37.2037.20 95.1495.14 0.240.24 95.3895.38 132.58132.58

Dadri (T)Dadri (T) 416.78416.78 1.1581.158 76.9776.97 90.5690.56 55.5755.57 146.13146.13 229.24229.24

Unchahar – II Unchahar – II ------ ------ ------ 103.28103.28 6.986.98 110.26110.26 473.75473.75

Dadrigas(L)Dadrigas(L) ------ ------ ------ 356.34356.34 71.2171.21 436.55436.55

*Rates for mixed fuel (gas+ liquid fuel, naphtha)

Payment to Inter State Generating Payment to Inter State Generating Stations (ISGS) from beneficiaries Stations (ISGS) from beneficiaries

under Availability Based Tariff under Availability Based Tariff (ABT)(ABT)

Capacity chargesCapacity charges Energy chargesEnergy charges Unscheduled Interchange (UI)Unscheduled Interchange (UI)

1000

900

800

700

600

500

400

300

200

100

00 2 4 6 8 10 12 14 16 18 20 22 24

Forecast ex-bus capability of Power Plant

Hours

MW

Net Injection Schedule

SEB - A's Requisition

SEB - A's Entitlement - (40% )

SCHEDULING

CAPACITY CHARGECAPACITY CHARGE

Capacity charge will be related to Capacity charge will be related to ‘availability’ of the generating station and ‘availability’ of the generating station and the percentage capacity allocated to the the percentage capacity allocated to the state. ‘Availability’ for this purpose means state. ‘Availability’ for this purpose means the readiness of the generating station to the readiness of the generating station to deliver ex-bus output expressed as a deliver ex-bus output expressed as a percentage of its rated ex-bus output percentage of its rated ex-bus output capability.capability.

ENERGY CHARGEENERGY CHARGE

Energy charges shall be worked out on the Energy charges shall be worked out on the basis of a paise per kwh rate on ex-bus basis of a paise per kwh rate on ex-bus energy scheduled to be sent out from the energy scheduled to be sent out from the generating station as per the following generating station as per the following formulaformula

Energy chargesEnergy charges = = Rate of energy Rate of energy charges charges

(paise/kwh) x (paise/kwh) x ScheduledScheduled Generation Generation (ex-bus MWh)(ex-bus MWh)

Energy Charges (paise/kwh) for Central Sector Energy Charges (paise/kwh) for Central Sector stations (Dec 2003)stations (Dec 2003)

Sl. No.Sl. No. Power StationPower Station Rate (Paise / Rate (Paise / KWh)KWh)

1.1. Salal Salal 59.6959.692.2. Tanakpur Tanakpur 59.6959.693.3. SingrauliSingrauli 75.8475.844.4. RihandRihand 78.9978.995.5. Anta/Auraiya/Dadri GTAnta/Auraiya/Dadri GT 95.0095.006.6. UnchaharUnchahar 110.00110.007.7. Dadri (Thermal)Dadri (Thermal) 145.00145.00

UNSCHEDULED INTERCHANGE (U I) :UNSCHEDULED INTERCHANGE (U I) :

Variation in actual generation / drawal with respect Variation in actual generation / drawal with respect to scheduled generation / drawal shall be accounted to scheduled generation / drawal shall be accounted for through Unscheduled Interchange (UI).for through Unscheduled Interchange (UI).

UI for generating station shall be equal to its total UI for generating station shall be equal to its total actual generation minus its scheduled generation.actual generation minus its scheduled generation.

UI for beneficiary shall be equal to its total actual UI for beneficiary shall be equal to its total actual drawal minus its total scheduled drawal.drawal minus its total scheduled drawal.

UNSCHEDULED INTERCHANGE (U I) :UNSCHEDULED INTERCHANGE (U I) :

UI shall be worked out for each 15 minute UI shall be worked out for each 15 minute time block.time block.

Charges for all UI transactions shall be based Charges for all UI transactions shall be based on average frequency of the time block.on average frequency of the time block.

UI rates shall be frequency dependent and UI rates shall be frequency dependent and uniform throughout the country.uniform throughout the country.

UNSCHEDULED INTERCHANGE (UI) RATESUNSCHEDULED INTERCHANGE (UI) RATES

Average frequency of 15 Average frequency of 15

minute time blockminute time blockUI Rate UI Rate

(Paise / KWh)(Paise / KWh)

50.5 Hz & Above50.5 Hz & Above 0.00.0

Below 50.50 Hz & Below 50.50 Hz & up to 50.48 Hzup to 50.48 Hz

5.65.6

Below 49.04 Hz & Below 49.04 Hz & up to 49.02 Hzup to 49.02 Hz

414.60414.60

Below 49.02 HzBelow 49.02 Hz 420.00420.00

Between 50.50 Hz Between 50.50 Hz & 49.02 Hz& 49.02 Hz

(50.5 – F/0.02) (50.5 – F/0.02) x 5.6x 5.6

UNSCHEDULED INTERCHANGE UNSCHEDULED INTERCHANGE (UI) RATES(UI) RATES

THUSTHUS

At 50.3 Hz, UI = 56 paise / KWhAt 50.3 Hz, UI = 56 paise / KWh At 50.2 Hz, UI = 84 paise / KWhAt 50.2 Hz, UI = 84 paise / KWh At 50.0 Hz, UI = 140 paise / KWhAt 50.0 Hz, UI = 140 paise / KWh At 49.8 Hz, UI = 196 paise / KWhAt 49.8 Hz, UI = 196 paise / KWh At 49.5 Hz, UI = 280 paise / KWhAt 49.5 Hz, UI = 280 paise / KWh

FREQUENCY LINKED UNSCHEDULED FREQUENCY LINKED UNSCHEDULED INTERCHANGE RATESINTERCHANGE RATES

FREQUENCY FREQUENCY (Hz)(Hz)

UI RATE UI RATE (Paise / KWh)(Paise / KWh)

49.049.0 42042049.149.1 39239249.249.2 36436449.349.3 33633649.449.4 30830849.549.5 28028049.649.6 25225249.749.7 224224

FREQUENCY FREQUENCY (Hz)(Hz)

UI RATE UI RATE (Paise / KWh)(Paise / KWh)

49.849.8 19619649.949.9 16816850.050.0 14014050.150.1 11211250.250.2 848450.350.3 565650.450.4 282850.550.5 00

AVAILABILITY BASED TARIFFAVAILABILITY BASED TARIFF

(A)(A) CAPACITY CHARGECAPACITY CHARGE(B)(B) ENERGY CHARGEENERGY CHARGE(C)(C) ADJUSTMENT FOR DEVIATIONS ADJUSTMENT FOR DEVIATIONS (U I CHARGE)(U I CHARGE)(A) = a function of the Ex-Bus MW availability of Power (A) = a function of the Ex-Bus MW availability of Power

Plant for the day declared before the day starts x Plant for the day declared before the day starts x SEB’s % allocation from the plantSEB’s % allocation from the plant

(B) = MWh for the day as per Ex-Bus drawal schedule for (B) = MWh for the day as per Ex-Bus drawal schedule for the SEB finalised before the day starts x Energy the SEB finalised before the day starts x Energy charge ratecharge rate

(C) = (C) = Σ Σ (Actual energy interchange in a 15 minute time (Actual energy interchange in a 15 minute time block – scheduled energy interchange for the time block – scheduled energy interchange for the time block) x UI rate for the time block block) x UI rate for the time block

TOTAL PAYMENT FOR THE DAY = (A) + (B) TOTAL PAYMENT FOR THE DAY = (A) + (B) ± (C) ± (C)

FEATURES :FEATURES :

((A) and (B) do not depend on actual plant A) and (B) do not depend on actual plant generation / drawal. No metering required for this generation / drawal. No metering required for this as they are based on off-line figures. All deviations as they are based on off-line figures. All deviations taken care of by (C)taken care of by (C)

No complication regarding deemed generation.No complication regarding deemed generation.

Perpetual incentive for maximizing generation and Perpetual incentive for maximizing generation and reducing drawal during deficit, but no incentive to reducing drawal during deficit, but no incentive to over generate during surplus.over generate during surplus.

UNSCHEDULED INTERCHANGES (UI)UNSCHEDULED INTERCHANGES (UI)I.E. DEVIATIONS FROM SCHEDULESI.E. DEVIATIONS FROM SCHEDULES

Makes all the players in the grid self-responsive and Makes all the players in the grid self-responsive and enhances merit order.enhances merit order.

Good UI helps in improving frequency and enables Good UI helps in improving frequency and enables one constituent to help the other (for meeting more one constituent to help the other (for meeting more consumer demand i.e reducing load shedding)consumer demand i.e reducing load shedding)

UI provides the mechanism for on-line displacement UI provides the mechanism for on-line displacement of costlier generation by cheaper generation : of costlier generation by cheaper generation : ultimate optimisation.ultimate optimisation.

REACTIVE ENERGY CHARGESREACTIVE ENERGY CHARGES Under ABT, a reactive energy charge in Under ABT, a reactive energy charge in

paise/kwh is applicable.paise/kwh is applicable.

The charges would be @ 4.0 paise/kVARh The charges would be @ 4.0 paise/kVARh upto 31upto 31stst March 2001 and escalated @ 5% per March 2001 and escalated @ 5% per annum.annum.

This would be applicable for reactive power This would be applicable for reactive power exchanges outside the 97-103% voltage band.exchanges outside the 97-103% voltage band.

TIME TABLE FOR EXCHANGE OF INFORMATIONTIME TABLE FOR EXCHANGE OF INFORMATION IN RESPECT OF SCHEDULINGIN RESPECT OF SCHEDULING

By 10.00 hrs.By 10.00 hrs. ISGSs shall advise NRLDC the Station-wise MW and MWh ISGSs shall advise NRLDC the Station-wise MW and MWh capabilitiescapabilities

By 1100 Hrs.By 1100 Hrs. NRLDC shall advise the States / Beneficiaries the Station NRLDC shall advise the States / Beneficiaries the Station wise MW & MWh entitlements.wise MW & MWh entitlements.

By 1500 hrs.By 1500 hrs. SLDCs/ Beneficiaries shall communicate the Station-wise SLDCs/ Beneficiaries shall communicate the Station-wise requisitions and details of bilateral exchanges to NRLDC.requisitions and details of bilateral exchanges to NRLDC.

By 1700 hrs.By 1700 hrs. NRLDC shall convey the ex-power plant despatch schedule NRLDC shall convey the ex-power plant despatch schedule to each ISGS and net drawal schedule to each State / to each ISGS and net drawal schedule to each State / Beneficiary. The details of unrequisitioned surpluses shall Beneficiary. The details of unrequisitioned surpluses shall also be intimated.also be intimated.

By 2200 hrs.*By 2200 hrs.* ISGSs / States / Beneficiaries shall inform the modifications, ISGSs / States / Beneficiaries shall inform the modifications, if any, for incorporating in the final scheduleif any, for incorporating in the final schedule

By 2300 hrs.By 2300 hrs. NRLDC shall issue the final despatch and drawal schedule.NRLDC shall issue the final despatch and drawal schedule.

* Since issuing the final despatch and drawal schedule is a critical activity * Since issuing the final despatch and drawal schedule is a critical activity and considerable time is involved in its preparation and carrying out and considerable time is involved in its preparation and carrying out requisite moderation, if any, it has been agreed to complete this activity by requisite moderation, if any, it has been agreed to complete this activity by 2100 hrs.2100 hrs.

Real time operationReal time operation

What all can happen on the day of operation?What all can happen on the day of operation?

1)1) Prospective revision of ISGS availabilityProspective revision of ISGS availability» Entitlement revised for remaining part of the Entitlement revised for remaining part of the

day.day.

State’s optionsState’s options Rework the requisitions to ensure maximum Rework the requisitions to ensure maximum

economy in the operation of power system economy in the operation of power system in the state.in the state.

Real time operationReal time operation2)2) Tripping of an ISGS unitTripping of an ISGS unit

» Immediate frequency dipImmediate frequency dip» State (SEB)’s drawal reduces and it receives UI State (SEB)’s drawal reduces and it receives UI

paymentpayment State’s optionsState’s options

Draw less than schedule & get UIDraw less than schedule & get UI Reduce net drawal further by increasing own Reduce net drawal further by increasing own

generation & get additional UIgeneration & get additional UI Draw as per schedule & forego UIDraw as per schedule & forego UI

Real time operationReal time operation3)3) Tripping of the State’s own generating unit?Tripping of the State’s own generating unit?

• State’s net drawal increases and it has to State’s net drawal increases and it has to pay UIpay UI

State’s optionsState’s options Continue to overdraw and pay UIContinue to overdraw and pay UI Reduce net drawal by load-shedding or Reduce net drawal by load-shedding or

bringing up all available generationbringing up all available generation Increase ISGS requisitionIncrease ISGS requisition Enter into bilateral with other SEBs for Enter into bilateral with other SEBs for

idle capacity, if anyidle capacity, if any

Real time operationReal time operation

4)4) Load crash in the stateLoad crash in the state Frequency increases and state underdraws Frequency increases and state underdraws

from the grid with UI implicationsfrom the grid with UI implications

State’s optionsState’s options Reduce own generation if respective energy rate is Reduce own generation if respective energy rate is

higher than the UI ratehigher than the UI rate Restore disconnected loads (if the recovery rate is Restore disconnected loads (if the recovery rate is

higher then the UI rate)higher then the UI rate) Reduce ISGS requisition if ISGS energy rate is higher Reduce ISGS requisition if ISGS energy rate is higher

than the UI ratethan the UI rate

Real Time Operation(Gen. Units)Real Time Operation(Gen. Units)1.1. In case of tripping of machineIn case of tripping of machine

Intimate to RLDC – New schedule shall become effective from 4Intimate to RLDC – New schedule shall become effective from 4 thth time block time block –– For initial 3 time blocks, plant has to bear the UI For initial 3 time blocks, plant has to bear the UI

Whether revival time is known –Whether revival time is known –If No, Declare reduced DC for remaining part of the dayIf No, Declare reduced DC for remaining part of the dayIf yes, Declare reduced DC for outage time and enhanced DC thereafterIf yes, Declare reduced DC for outage time and enhanced DC thereafter

2. Change in inflows: Schedule gets revised w.e.f. 62. Change in inflows: Schedule gets revised w.e.f. 6 thth time block time block

3. Schedule change by RLDC because of Transmission constraints3. Schedule change by RLDC because of Transmission constraintsSchedule change w.e.f 4Schedule change w.e.f 4thth time block (New schedule) time block (New schedule)Initial 3 blocks – as per actual (SEM)Initial 3 blocks – as per actual (SEM)Generation to be revised as per new schedule - ImmediatelyGeneration to be revised as per new schedule - Immediately

4. Suo-moto Rescheduling by NRLDC 4. Suo-moto Rescheduling by NRLDC Initial 3 blocks –As per actual generation (SEM Reading)Initial 3 blocks –As per actual generation (SEM Reading)44thth Block – New value for generation schedule Block – New value for generation schedule

Generation to be revised as per new schedule - ImmediatelyGeneration to be revised as per new schedule - Immediately

Special Energy Meters (SEMs) Special Energy Meters (SEMs) specificationsspecifications

0.2 S accuracy class for active power as per IEC-687, 0.2 S accuracy class for active power as per IEC-687, 19921992

Static, totally tamper proofStatic, totally tamper proof

Two standard models-1A and 5ATwo standard models-1A and 5A

Non-volatile memory for ten daysNon-volatile memory for ten days

Harmonics filtered out and only the fundamental energy Harmonics filtered out and only the fundamental energy recordedrecorded

SEM Specifications (contd..)SEM Specifications (contd..) Recording in secondary quantities. CT/CVT ratios to Recording in secondary quantities. CT/CVT ratios to

be applied at control centre.be applied at control centre.

Net energy (Wh) exchange in each 15-minute blockNet energy (Wh) exchange in each 15-minute block

Cumulative Wh transmittal at each mid-night.Cumulative Wh transmittal at each mid-night.

Average frequency in each 15-minute time block Average frequency in each 15-minute time block stores as a two-digit code.stores as a two-digit code.

Cumulative reactive energy register for voltage Cumulative reactive energy register for voltage below 97%below 97%

SEM Specifications (contd..)SEM Specifications (contd..) Cumulative reactive energy register for voltage Cumulative reactive energy register for voltage

above 103%above 103% High accuracy of internal clock (one minute per High accuracy of internal clock (one minute per

month or better) with restricted advance/retard month or better) with restricted advance/retard facility.facility.

VT supply disturbance time tagged with * markVT supply disturbance time tagged with * mark No separate auxiliary supply- only optical coupler No separate auxiliary supply- only optical coupler

for data collection.for data collection. Calibration once in five years at a test lab (0.05 Calibration once in five years at a test lab (0.05

accuracy class test equipment or better)accuracy class test equipment or better) On-site accuracy check once a year using portable On-site accuracy check once a year using portable

0.2S test equipment0.2S test equipment

Regional Energy Accounting (REA)Regional Energy Accounting (REA) Monday to Sunday is the weekly accounting Monday to Sunday is the weekly accounting

periodperiod

SEM readings collected and transferred to SEM readings collected and transferred to RLDCs on Monday/TuesdayRLDCs on Monday/Tuesday

Processed data forwarded to REBs on ThursdayProcessed data forwarded to REBs on Thursday

Weekly UI account issued by REBs on TuesdayWeekly UI account issued by REBs on Tuesday

Thank You