Indian Power System Peculiarities & Solutions S K Soonee Executive Director NRLDC

Landmarks … Pre – Independence Period –First Hydel Project (Darjeeling) – 1897 –First Steam Plant (1000 KW) Calcutta – 1899 –Survey of Hydro Power Potential – –Generation during World War – II – 1140 –Generation at the time of Independence – 1349 MW

Phenomenal expansion since Independence Phenomenal expansion since Independence  Generation : 1349 MW 112,058 MW (in 1947) (in 2004) (in 1947) (in 2004)  Grid : Local grid – at the time of Independence. State Grids – emerged in 1960s. Regional Grids – in 1970s. Five Regional Grids – Northern, Western, Southern, Eastern & North-eastern Eastern & North-eastern National Grid – All Five Regions Interconnected (2002) Formation Of Central Grid by Synchronizing North Eastern - Eastern – Western Grids (2003) Indian Power Grid – its Evolution

INDIAN POWER SECTOR  India is a FEDERAL country  Electricity a concurrent subject – Both Central and State Govts. responsible for its development  Multiplicity of players  Roles are demarcated

Growth of installed capacity for electricity in India

Regional Grids Of India

Inter Regional Links Present IR Capacity = 8,500 MW By the year 2012 = 30,000 MW 500 MW 1000MW 2000MW 1200 MW

RTU SUB LDC SLDC ERLDC WRLDCNRLDCSRLDCNERLDC NLDC 23 Nos. 51 Nos Nos. Unified Grid Operation 5 Nos. National Level Regional Level State HQ Level Group / Distt Level Plant / Sub- Station Level

Regional Grid State - A State - B State - C CS - 1 MPP CS - 2 RLDC Coordinates Control Areas

SEB’s Grid Discom - A Discom - B Discom - C STATE IPP CENTRAL SHARE STATE GENR. SLDC Coordinates Directs Control Areas TRADER Trading Consumer Trading

Hierarchy  Policy and Administrative issues Govt. (through Ministry of Power)  Power Sector Planning Central Electricity Authority (CEA) A Central Govt body A Central Govt body Responsible for coordinated planning Responsible for coordinated planning Technical Advisor to Govt. Technical Advisor to Govt.  Regulation CERC at Center and SERC at State level  Operation -NLDC -RLDC -RLDC -SLDC -SLDC Under Implementation by POWERGRID Responsible for Regional Grid Operation Responsible for State Grid Operation

 Generation Delicensed  Transmission Licensed activity Overall development of central sector transmission from concept to commissioning and its operation entrusted to Central Transmission Utility (CTU- a statutory body under GoI), i.e POWERGRID Overall development of central sector transmission from concept to commissioning and its operation entrusted to Central Transmission Utility (CTU- a statutory body under GoI), i.e POWERGRID Similarly, STU (- a statutory body under State Govt.) responsible for State sector transmission Similarly, STU (- a statutory body under State Govt.) responsible for State sector transmission  Distribution Licensed  Trading Licensed  Grid Management Entrusted to CTU (POWERGRID) Entrusted to CTU (POWERGRID) NLDC under implementation NLDC under implementation Operation of Regional Grids by RLDCs Operation of Regional Grids by RLDCs Operation of State Power System by SLDCs in association with RLDCs Operation of State Power System by SLDCs in association with RLDCs Generation, Transmission & Distribution

States were generally in the form of: 1.Vertically Integrated Utilities having -Own Generation -Own Transmission -Own Distribution 2.Having fixed shares in the Central Sector 3.Counting on Load-Generation Balance within the State Pre – Reforms Scenario

1. State regulatory commissions (SERCs) constituted 2. SERCs have issued tariff orders 3. States have unbundled their SEBs 4. States are in the process of privatising distribution 5. States have signed MoUs with the Ministry of Power 6. All around emphasis to provide 100% metering Indian Power Sector Reforms

Indian Power Sector-Distribution  Distribution originally with the State Electricity Boards (SEBs) with licenses given out for some areas to private.  After unbundling of SEBs, separate (DISCOMS) formed at state level. Privatisation of DISCOMS already done in two states viz. Delhi and Orissa.  Emphasis on metering, loss reduction at this level with the Central Govt. acting as a catalyst through assistance under APDRP.

 Defines responsibilities between Utilities, RLDCs and REBs  Defines scheduling mechanism for day ahead scheduling of Generation and Drawal  Specified frequency bands for operation of regional grids  Frequency stabilization through free governor mode of generating units  Defines charge for Reactive Energy drawal Indian Electricity Grid Code

Commercial Mechanism A B T INDIAN POWER SECTOR

Components of inter-utility tariff (Pre – ABT Mechanism)  Fixed charges  Interest on loans  Depreciation  O & M charges  Return on equity  Interest on Working Capital  Energy charges (fuel cost)  Incentives  Surcharge & other levies  No charge for reactive energy

AVAILABILITY BASED TARIFF (A) CAPACITY CHARGE (B) ENERGY CHARGE (C) ADJUSTMENT FOR DEVIATIONS (U I CHARGE) (U I CHARGE) (A) = a function of the Ex-Bus MW availability of Power Plant for the day declared before the day starts x SEB’s % allocation from the plant (B) = MWh for the day as per Ex-Bus drawal schedule for the SEB finalised before the day starts x Energy charge rate (C) = Σ (Actual energy interchange in a 15 minute time block – scheduled energy interchange for the time block) x UI rate for the time block TOTAL PAYMENT FOR THE DAY = (A) + (B) ± (C)

FEATURES :  ( A) and (B) do not depend on actual plant generation / drawal. No metering required for this as they are based on off-line figures. All deviations taken care of by (C)  No complication regarding deemed generation.  Perpetual incentive for maximizing generation and reducing drawal during deficit, but no incentive to over generate during surplus.

UNSCHEDULED INTERCHANGES (UI) I.E. DEVIATIONS FROM SCHEDULES  Makes all the players in the grid self-responsive and enhances merit order.  Good UI helps in improving frequency and enables one constituent to help the other (for meeting more consumer demand i.e reducing load shedding)  UI provides the mechanism for on-line displacement of costlier generation by cheaper generation : ultimate optimisation.

REACTIVE ENERGY CHARGES Under ABT, a reactive energy charge in paise/kwh is applicable. Under ABT, a reactive energy charge in paise/kwh is applicable. This would be applicable for reactive power exchanges outside the % voltage band. This would be applicable for reactive power exchanges outside the % voltage band.

Planning Criterion INDIAN POWER SECTOR

 Generation Level  Demand  Margins  LOLP  Generation Mix  Peak Demand  Energy Demand  Plant Selection  Economics  Govt. Priorities  Transmission Requirement  Resource Availability  Unit Size  Economics  Grid Stability  Resources Generation Planning

 Long Term Forecast  Load Potential  Geography  Rate of Growth  Resources  Short Term Forecast  Current Rate of growth  Resources  Five year plans  Suppressed demand  Industrial growth  Govt. priorities Load Forecasting

ISTS shall be capable of withstanding and be secured against the following outages without necessitating load shedding or rescheduling of generation during steady state operation. Outage of a 132 kV D/C line or Outage of a 220 kV D/C line or Outage of a 400 kV S/C line or O utage of a single ICT PLANNING CODE FOR ISTS Planning Criteria :- Continued …..

PLANNING CODE FOR ISTS Planning Criteria :- or Outage of one pole of HVDC bipole or Outage of 765 kV S/C line The aforesaid contingencies would be superimposed over a planned outage of another 220 kV D/C line or 400 kV S/C line in another corridor and not emanating from the same sub-station. ISTS shall be capable of withstanding the loss of most severe single system infeed without loss of stability.

PLANNING CODE FOR ISTS Planning Criteria :- ANY ONE OF THE AFORESAID EVENTS SHALL NOT CAUSE o loss of supply o abnormal frequency on sustained basis o unacceptable high or low voltage o system instability o unacceptable overloading of ISTS elements

REASONS FOR GRID CONTINGENCIES  EQUIPMENT FAILURE EQUIPMENT FAILURE  WEAK TRANSMISSION SYSTEM WEAK TRANSMISSION SYSTEM  OPERATIONAL ERROR OPERATIONAL ERROR  GRID INDISCIPLINE GRID INDISCIPLINE  MULTIPLE OUTAGES DUE TO WEATHER  CASCADED TRIPPING DUE TO OVERLOAD

Regualtory Framework

ROLE OF REGULATORY AUTHORITIES Central Electricity Regulatory Authority – CERC  Regulate tariff of generating companies supplying power to more than one state  Determine Tariff & Regulate for Inter-state transmission system of electricity  Specify terms and conditions for determination of tariff  Issue of licenses for Inter-state transmission & trading  Dispute adjudication of various kinds including those amongst RLDC and constituents  Specify Grid code  Specify regulations for “ Open Access ”  Advise Central govt. on National Electricity policy & tariff policy, and on efficiency & economy measures including investment promotion

ROLE OF REGULATORY AUTHORITIES State Electricity Regulatory Authority – SERC  Similar functions at State level Generating companies & Intra-State transmission of electricity

Issues Of Importance

ISSUES OF IMPORTANCE Provide adequate level of redundancy in transmission network Generation to be augmented with load increase Load regulatory measures by utilities in the event of shortages Adequate reactive compensation to be provided at load end

Issues of Importance Uneven disposition of energy resources – long transmission lines Uneven disposition of energy resources – long transmission lines  Major Hydro resources in NER & NR  Coal reserves mostly in Bihar/Orissa/West Bengal  Cost of power transmission lower than cost of fuel transportation Some Regions are no longer Self-sufficient Some Regions are no longer Self-sufficient  Major resources in SR exhausted  In NR hydro resources having long gestation period Unbalanced Growth of different Regions Unbalanced Growth of different Regions  Some regions are surplus and some are deficit. Optimization of generation capacity addition Optimization of generation capacity addition  Utilizing time diversity  Spinning reserve optimization

Development of National Grid – Major Considerations Development in a phased manner – commensurate with generation/ load growth Development in a phased manner – commensurate with generation/ load growth Conservation of Right-of-Way - especially in areas with scarcity of ROW ---- viz. area near hydro, chicken-neck area, forest area, town etc. Conservation of Right-of-Way - especially in areas with scarcity of ROW ---- viz. area near hydro, chicken-neck area, forest area, town etc.  In forest area with rich flora & fauna, construction of line with high towers ---- no forest cutting required. Minimization of transmission cost - immediate as well as long-term basis. Minimization of transmission cost - immediate as well as long-term basis. Flexible enough to accommodate change in load- generation pattern. Flexible enough to accommodate change in load- generation pattern.

Major Challenges Proper Load Dispatch & Communication Facilities  POWERGRID is implementing ULDC schemes in all five regions.  Establishment of National Load Despatch Centre (NLDC) by interconnecting all the regions. Integrated Grid Operation  Strict adherence to grid discipline to maintenance of voltage and frequency.  Operation of generating units in free governor mode.  Implementation of “Availability Tariff” having provision of penalties and incentives to encourage grid discipline.

MEN EQUIPMENT PROCEDURE Vital Elements:

Departures From Conventional Practices:  Variation in Frequency permitted  Interchanges allowed to deviate from schedule  Frequency linked generation dispatch  Frequency linked pricing of deviations  Trading could be in the form of deviations with UI Rate providing the input signal

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