ANCILLARY SERVICES

ANCILLARY SERVICES THE NEXT STEP IN MARKET GRANULARISATION

DEFINITION Ancillary services are defined as all those activities on the interconnected grid that are necessary to support the transmission of power in maintaining and ensuring reliable operation and the required degree of quality and safety.

WHY ANCILLARY SERVICES? 

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SYSTEM OPERATOR DUTIES CONTROL THE FREQUENCY OF THE SYSTEM WITHIN CERTAIN BOUNDS. CONTROL THE VOLTAGE QUALITY AND PROFILE OF THE SYSTEM WITHIN CERTAIN BOUNDS MAINTAIN STABILITY OF THE SYSTEM PREVENT OVERLOADS IN THE TRANSMISSION SYSTEM RESTORE THE SYSTEM OR PORTION OF THE SYSTEM AT THE EARLIEST WHEN REQUIRED. TRANSPARENCY IN THE SYSTEM

WHAT ARE ANCILLARY SERVICES 

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Unbundled Services to facilitate market operations

Voltage Support Regulation Help to maintain reliable operation

Reserves Scheduling Consists of physical equipment and human resources Support

NERC IDENTIFIED AND DEFINED 12 SERVICES   

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SYSTEM CONTROL VOLTAGE CONTROL REGULATION OPERATING RESERVES  

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SPINNING SUPPLEMENTAL

ENERGY IMBALANCE

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LOAD FOLLOWING LOSS REPLACEMENT BACKUP SUPPLY DYNAMIC SCHEDULING SYSTEM BLACK-START NETWORK STABILITY

FERC REQUIRES THESE 6 

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NORMAL OPERATIONS REQUIRE 6 SERVICES TO MAINTAIN GENERATION/LOAD BALANCE System control Voltage control Regulation Energy imbalance Load following Loss replacement

FERC ANCILLARY SERVICES CATEGORY -1 CATEGORY-1: SERVICES REQUIRED FOR ROUTINE OPERATION 

SYSTEM CONTROL 

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VOLTAGE CONTROL 

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THE INJECTION OR ABSORPTION OF REACTIVE POWER FROM GENERATORS OR CAPACITORS TO MAINTAIN SYSTEM VOLTAGES WITHIN REQUIRED RANGES.

REGULATION 

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THE CONTROL AREA OPERATOR FUNCTIONS THAT SCHEDULE GENERATION AND TRANSACTIONS AND CONTROL GENERATION IN REAL-TIME TO MAINTAIN GENERATION/LOAD BALANCE.

THE USE OF GENERATION OR LOAD TO MAINTAIN MINUTE-TOMINUTE GENERATION/LOAD BALANCE WITHIN THE CONTROL AREA.

LOAD FOLLOWING/ENERGY IMBALANCE 

THE USE OF GENERATION TO MEET THE HOUR-TO-HOUR AND DAILY VARIATIONS IN LOAD

FERC ANCILLARY SERVICES CATEGORY -2

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CATEGORY-2: SERVICES NEEDED TO PREVENT AN OUTAGE FROM BECOMING A CATASTROPHE

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SPINNING RESERVES

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SUPPLEMENTAL RESERVES

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NETWORK STABILITY SERVICES CATEGORY-1 CAN ALSO ACT LIKE CATEGORY-2 SERVICES AND PREVENT VOLTAGES FROM DECAYING SO FAR THAT VOLTAGE COLLAPSE OCCURS, AND SYSTEM CONTROL IS REQUIRED TO MANAGE THESE SERVICES.

FERC ANCILLARY SERVICES CATEGORY -3 

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CATEGORY-3: SERVICES NEEDED TO RESTORE THE SYSTEM AFTER A BLACKOUT SYSTEM BLACKSTART CAPABILITY 

THE ABILITY OF A GENERATING UNIT TO PROCEED FROM A SHUTDOWN CONDITION TO AN OPERATING CONDITION WITHOUT ASSISTANCE FROM THE ELECTRICAL GRID AND THEN TO ENERGIZE THE GRID TO HELP OTHER UNITS START AFTER A BLACKOUT OCCURS.

RESERVES 

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IMPORTANT FOR BOTH ENERGY AND REACTIVE POWER NEEDED FOR MAINTAINING THE INTEGRITY OF THE TRANSMISSION SYSTEM DESIGNED TO RESPOND TO UNCERTAINITIES  

GENERATION OUTAGE LOAD VARIATIONS

TYPES OF RESERVES 

SPINNING: 

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SUPPLEMENTAL    

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FREQUENCY STABILISATION AVAILABLE INSTANTLY TIME OF RESPONSE – FEW SECONDS TO 5 MINUTES CAN BE FAST START UNITS OR DMS LOADS NO MANUAL INTERVENTION ENERGY REQUIRED IS NOT LARGE ON-BARS FOR SHORT PERIODS OF TIME ENERGY BALANCING TIME OF RESPONSE – SEVERAL MINUTES TO HALF-HOUR MAY REQUIRE MANUAL INTERVENTION LARGER ENERGY REQUIREMENTS

BACK-UP  

TIME OF RESPONSE – MORE THAN HALF-HOUR EXPECTED TO STAY ON BARS FOR A LONGER PERIOD

FREQUENCY REGULATION 

PRIMARY FREQUENCY CONTROL  

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SECONDARY FREQUENCY CONTROL 

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DROOP SETTING FREQUENCY RESPONSE OF HVDC LINK AUTOMATIC GENERATION CONTROL DIRECT CONTROL OF SPECIFIED PLANTS ABILITY TO DISCONNECT DEMAND

FREQUENCY CONTROL CAN ALSO BE ATTAINED BY SENDING PRICE SIGNALS TO GENERATORS(ABT?)

FREQUENCY RANGE AND ACTIONS

FREQUENCY BAND

AVERAGE RESERVE CLEARING PRICES IN NYISO IN 2002 

10 Minute Spin

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East: $3.03 West: $2.82

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10 Minute Non Synch

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East: $1.51 West: $1.27

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30 Minute Reserve: $1.13

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LOAD-FOLLOWING RESERVE 

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TYPICALLY 1% OF CAPACITY IS OF THIS TYPE LINKED TO AGC AND FGMO HIGHER O&M COSTS AND HEAT RATES COST INCLUDES FIXED COSTS FIXED COSTS ARE HIGHER SINCE LIFETIME OF THE UNIT IS LOWERED

REACTIVE SUPPORT SERVICES

VOLTAGE CONTROL EQUIPMENT

NETWORK STABILITY SERVICES 

MAINTENANCE AND USE OF SPECIAL EQUIPMENT (POWER-SYSTEM STABILIZERS AND DYNAMIC-BRAKING RESISTORS) TO MAINTAIN A SECURE TRANSMISSION SYSTEM.

PROVIDING ANCILLARY SUPPORT 

ANCILLARY SERVICE CAN BE ARRANGED BY 

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OWNING THE EQUIPMENT NECESSARY TO PROVIDE THE SERVICE CONTRACTING WITH THE ANCILLARY SERVICE PROVIDERS ON A LONG TERM BASIS CREATING A MARKET FOR SUPPLY OF SERVICE.

PRICING ANCILLARY SERVICES 

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COSTS ARE NOT TRIVIAL :- 10% OF ENERGY CHARGES ARE TOWARDS ANCILLARY SERVICES IN USA SIZING HAS TO BE DONE FOR THE GRID BASED ON REGULATORY REQUIREMENT RESOURCES HAVE TO BE GROUPED IN DIFFERENT SERVICES BASED ON HARD DATA :DETERMINING THE SERVICE QUALITY ORDER 

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CRUCIAL FOR BIDDING

COSTING IS USUALLY ON REPLACEMENT COST, LOST PROFITS AND OPPORTUNITY COSTS

TYPICAL PRICING IN CALIFORNIA ISO

ABT AND THE ANCILLARY MARKET 

CONCEPT OF LOOSE POWER POOL  

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REACTIVE POWER PRICING MECHANISM IN PLACE FOR THE LOOSE POWER POOLS    

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THIS IS FOR THE AREA AS A WHOLE REACTIVE SUPPORT MAY STILL BE REQUIRED AT VARIOUS BUSES THIS OPENS UP A MARKET OPPURTUNITY PRESENTLY MVAR BY GENERATORS ARE NOT COMMERCIALLY MONITORED

UI MECHANISM PROVIDES A COMPREHENSIVE BALANCING MARKET AND A PRICING THRESHOLD FOR EMBEDDED ANCILLARY SERVICES/MARKETS REGULATOR HAS PROVIDED LARGE BANDWIDTH FOR FREQUENCY   

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RESPONSIBILITY OF RESERVES, LOAD FOLLOWING ETC LIES WITH THE STATES RESERVES, LOAD FOLLOWING ETC IN STATE PURVIEW

LOAD FOLLOWING, SPINNING RESERVES YET TO MATURE FGMO ALREADY IN PLACE AS MANDATED SERVICE AVR IN SERVICE IS ALSO MANDATED

DUE TO UNBUNDLING GENCO’S MAY NOT READILY PART WITH FREE SERVICES LIKE IN THE PAST

UI PROVIDES THE REFERENCE PRICE FOR MW BASED IMBALANCE ANCILLARY SERVICES ISGS

STATE SYSTEM

POWER POOL ABT UI PRICE

OPPORTUNITY FOR PROCURING MVAR FROM ISGS AS AN ANCILLARY SERVICE