ancillary services in electricity markets€¦ · frequency control ancillary services a certain...
TRANSCRIPT
02-03-2016 Side 1
Department of Electrical Engineering, IIT Kanpur (INDIA)
Ancillary Services in Electricity
Markets
S.N. Singh, Professor
Department of Electrical Engineering
Indian Institute of Technology Kanpur
Email: [email protected]
02-03-2016 Side 2
Department of Electrical Engineering, IIT Kanpur (INDIA)
Ancillary Services
• The literal meaning of the word ancillary is providing
support or help.
• Generally, the System Operator (SO) manages ancillary
services for ensuring security, reliability, stability and
quality of the power supply to the consumers.
• Ancillary services can be provided by generators, Load
Serving Entities (LSEs) and transmission operators.
• Ancillary services are classified, procured and
remunerated depending upon the operational practices of
the Electricity Supply Industry (ESI).
02-03-2016 Side 3
Department of Electrical Engineering, IIT Kanpur (INDIA)
• NERC defines Ancillary Services as
“An Interconnected operation services necessary to effect transfer of electricity between purchasing and selling entities, and which a transmission provider must include in an open access transmission tariff.”
• Ancillary services consist of services required for
- Maintaining generation and load balance (frequency control)
- Maintaining Voltage and reactive power support
- Maintaining generation and transmission reserves
- Emergency preparedness (system restart & stability control)
Ancillary services cost may be about 10% of total generation and transmission cost. Most of it are required for power balancing/frequency regulation, loss make-up and voltage/reactive power support.
02-03-2016 Side 4
Department of Electrical Engineering, IIT Kanpur (INDIA)
Classification of Ancillary Services
SRAS
Secondary FC
Primary FC
Tertiary FC
Ancillary Services
PFCAS
NCAS FCAS
VCAS
Primary VC
Secondary VC
Tertiary VC
Ref: Guide to ancillary services in the National Electricity Market, National Electricity Market Management Company.
02-03-2016 Side 5
Department of Electrical Engineering, IIT Kanpur (INDIA)
Frequency Control Ancillary Services
A certain amount of active power, called frequency control reserve, is kept available to perform this task.
Three levels of control are generally used to achieve FCAS:
Primary frequency control (a response period of 5 to10s),
Secondary frequency control (10s to 15min ) and
Tertiary frequency control (10 to 30min).
Frequency control reserves required to perform above control tasks can be of
positive frequency control reserve and
negative frequency control reserve.
02-03-2016 Side 6
Department of Electrical Engineering, IIT Kanpur (INDIA)
Network Control Ancillary Services
These are the services required to maintain the network parameters within permissible range.
VCAS are required for supporting the voltage to be maintained within the permissible limit. Three levels of control are generally used to achieve VCAS:
Primary voltage control,
Secondary voltage control and
Tertiary voltage control.
Power flow control AS (PFCAS) are needed for the purpose of improving Available Transfer Capability (ATC) and the performance of real time operation considering network constraints.
02-03-2016 Side 7
Department of Electrical Engineering, IIT Kanpur (INDIA)
MVAr
Under excitation limit
Pg G
SgQg
Qg E
Qg
op
D
C
B A O
MW
Field current limit
Qgmin
Pgmax
F
Armature current limit
02-03-2016 Side 8
Department of Electrical Engineering, IIT Kanpur (INDIA)
System Restart Ancillary Services
These are the services related to backup capacity of the system and the capacity that is required to return the system to a normal operation after a major blackout.
02-03-2016 Side 9
Department of Electrical Engineering, IIT Kanpur (INDIA)
Technologies Used for Provision of AS
Ancillary Services Technologies Used
FCAS Governor, AGC, Rapid unit loading,
Rapid unit unloading, Demand side load
shedding
NCAS Generators, Capacitors, Inductors,
Synchronous condensers, FACTS
controllers
SRAS Generators
02-03-2016 Side 10
Department of Electrical Engineering, IIT Kanpur (INDIA)
Procurement of Ancillary Services Compulsory Provision
• As part of connecting conditions, a fixed amount of ancillary services is provided.
• Consequences: (i) volume of service provided may exceed what is actually needed, (ii) potentially low cost providers are treated on the same basis as more expensive one.
Market Based Provision
• Bilateral contracts: (i) this form of procurement lacks transparency, (ii) this type of negotiation can be long-term, complex and costly, (iii) because of high transaction cost of contracts, price and volume often remain fixed for a long time.
• Both tendering process and creation of a spot market enhance transparency and foster competition.
02-03-2016 Side 11
Department of Electrical Engineering, IIT Kanpur (INDIA)
Remuneration of Ancillary Services The remuneration for an ancillary service may combine
several components to reflect the various costs of
ancillary service provider such as
• Availability price
• Utilization price
• Fixed cost
• Variable cost
• Opportunity cost
02-03-2016 Side 12
Department of Electrical Engineering, IIT Kanpur (INDIA)
Remuneration of Ancillary Services
Remuneration Methods
• Regulated price (set by regulator or SO and usually same for
all providers): it is justified when market power is issue but it
reflects imperfect cost as cost changes with time and condition.
• Pay as Bid price (the supplier receives the price of its
accepted offer): It is good when the quality of the ancillary
services offered is highly differentiated. However, it does not give
providers an incentive to bid their marginal cost, except when
market concentration is low.
• Common clearing price (all the successful providers are paid
the price of the most expensive accepted or the least expensive
rejected offer)
02-03-2016 Side 13
Department of Electrical Engineering, IIT Kanpur (INDIA)
• While designing an ancillary services
market, a number of aspects have to be
considered,
• Time frame of the market,
• Type of the market (bilateral or competitive bid
based),
• Type of procurement (sequential or simultaneous),
• Settlement rules (price based or bid type, price based
on usage type, marginal price or pay as bid),
• Recovery (charging) scheme (uplift in energy charge,
use of system charge or other methods)
02-03-2016 Side 14
Department of Electrical Engineering, IIT Kanpur (INDIA)
International Practices
02-03-2016 Side 15
Department of Electrical Engineering, IIT Kanpur (INDIA)
England & Wales Electricity Market
02-03-2016 Side 16
Department of Electrical Engineering, IIT Kanpur (INDIA)
• The restructuring process of the electric supply
industry (ESI) began in 1989 in order to reduce
the government intervention in the economy, and
total liberalization was reached in 1991.
• It was known as UK Pool. New Grid Company
(NGC) was responsible Market clearing, providing
the transmission system and ancillary services
02-03-2016 Side 17
Department of Electrical Engineering, IIT Kanpur (INDIA)
Competing GeneratorsAncillary Services
Distributors
Power Exchange (PX) System Operator
(SO)
Transmission Facilities
ControlMonitor
DispatchBid
ForecastSell
NGC
02-03-2016 Side 18
Department of Electrical Engineering, IIT Kanpur (INDIA)
New Electricity Trading Arrangement (NETA) in UK
• Before the March 2001, any generator
exporting more than 50 MW on to the system is
required to hold a generation licence and to
trade its output via an open commodity market,
the Electricity Pool.
• CfDs were essentially financial instruments, the
main purpose of which is to hedge risk
• After March 2001, New wholesale electricity
trading arrangements (NETA) was introduced .
02-03-2016 Side 19
Department of Electrical Engineering, IIT Kanpur (INDIA)
• In the NETA design the old day- ahead pool based on a coordinated - spot market with a market- clearing price was replaced by a three- and- a half- hour ahead balancing system with a complex pricing scheme that features pay- as- bid mechanism with rules intended to penalise imbalances.
• The governance arrangements that supported NETA include the establishment of a Balancing and Settlement Code (BSC) Panel, to oversee the Code and to to provide or procure a range of operational and administrative services, both directly and through contracts with service providers.
02-03-2016 Side 20
Department of Electrical Engineering, IIT Kanpur (INDIA)
The new arrangements include:
• Forward and futures markets
• a Balancing Mechanism in which the NGC, as system
operator, accepts offers of and bids for electricity
close to real time to enable it to balance the system;
• a Settlement Process for charging participants whose
contracted positions do not match their metered
volumes of electricity, for the settlement of accepted
Balancing Mechanism offers and bids and for clearing
costs of balancing the system.
• Ancillary service is managed by NGC and the cost
associated with the provision of AS are transferred
to the Consumers through transmission payment.
02-03-2016 Side 21
Department of Electrical Engineering, IIT Kanpur (INDIA)
Two major Ancillary Services
• Frequency Controlled o Primary frequency regulation
o Secondary frequency regulation
o Tertiary frequency regulation
• Voltage Control
• Replacement or supplementary reserve
02-03-2016 Side 22
Department of Electrical Engineering, IIT Kanpur (INDIA)
Frequency Control
Required to keep the frequency between 49.5 and 50.5 Hz.
During contingency, frequency is allowed to drop under 49.5 Hz, but
for not more than 1 minute.
Primary frequency regulation is mandatory for all generators with
installed capacity of over 50MW.Generators are set for a droop of 3–5%.
Secondary frequency regulation is considered as a commercial service
and it is not considered as a mandatory provision.
Generators provide it using AGC.
The consumers pay through an increase in their electricity tariff
which includes capacity, operation and compensation.
02-03-2016 Side 23
Department of Electrical Engineering, IIT Kanpur (INDIA)
•NGC responsible for managing ancillary services.
•The costs associated recovered from the consumers through uplift in
transmission payment mechanism.
Voltage Control:
Provision: all the generation units with a capacity over 30 MW.
Voltage must be kept within the range of Vnom+- 10% for 400, 275
and 132 kV networks and the power factor (PF) between 0.85
capacitive and 0.95 inductive.
The ratio of capacity price to operation price is approximately 1:2.
02-03-2016 Side 24
Department of Electrical Engineering, IIT Kanpur (INDIA)
Technical aspects of ancillary services provision in England and Wales
Primary FCAS Secondary FCAS VCAS
Response time 10s 30s Instantaneous
Duration 20s 30min Not specified
Provider Generators and large
customers with load
shedding
Generators with
AGC and load
shedding
Generators with capacities over
30MW
Monitoring Continuous,
frequency must always be
between 49.5 Hz to 50.5 Hz
Daily monitoring Voltage range must be kept
between Vnom + 10% for 400,
275 and 132 kV transmission
system
Necessary
amount
Generation droop between
3% to 5% sensibility to
frequency changes smaller
than + 15 mHz
Annually
determined by
system operator
Based on historical levels,
assigned in MVAr for every
hour
Commitment Mandatory for generators
with capacities over 50 MW
Optional Mandatory to keep the power
factor between 0.85 (capacitive)
and 0.95 (inductive)
02-03-2016 Side 25
Department of Electrical Engineering, IIT Kanpur (INDIA)
Primary FCAS Secondary FCAS VCAS
Main costs
identified
Insignificant and
difficult to
determine
Low costs, difficult
to determine
capacity and operation
Transaction
mechanism
Annual bilateral
contracts
Annual bilateral
contracts, and
competitive auctions
an auction and offer
mechanism operated on a
semester basis
Payment to
providers
For capacity,
usage (spot price)
and compensation
if applied
For capacity,
operation (spot
price) and
compensation
For capacity, usage
Customer’s
payments
Through an uplift
charge
Through an uplift
charge
Through an uplift charge
Price
discovery
US $3.9/MWh US $4.3/MWh Capacity between
$0/MWArh and 0.58/MVArh,
usage $1.31/MVArh
Economic aspects of ancillary services provision in England and Wales
02-03-2016 Side 26
Department of Electrical Engineering, IIT Kanpur (INDIA)
California Deregulation Process
02-03-2016 Side 27
Department of Electrical Engineering, IIT Kanpur (INDIA)
• On March 31, 1998 California became the first sate to offer all customers a choice of electric service providers. There are three significant characteristics in California Model.
- A Zonal approach is applied to simplify the transmission pricing scheme, including nodal and congestion charge assessing.
- Multiple separate energy forward markets, each with a supply and demand portfolio managed by a Scheduling coordinator (SC) or PX, have been introduced.
02-03-2016 Side 28
Department of Electrical Engineering, IIT Kanpur (INDIA)
28
Competing GeneratorsAncillary Services
Distributors
California PX
System Operators
(SO)
Transmission systems
Scheduling
Co-ordinators
(SC)
Brokers
ControlMonitor
DispatchBid
ForecastSell
California ISO
02-03-2016 Side 29
Department of Electrical Engineering, IIT Kanpur (INDIA)
CALIFORNIA ASM
Four types:
1. regulation up,
2. regulation down,
3. spinning reserve
4. non-spinning reserve.
♦ Ancillary Services: RT and DA
♦ Co-optimized with energy in both RT and DA
♦ Spinning and non-spinning reserves with scarcity pricing
♦ Regulation
02-03-2016 Side 30
Department of Electrical Engineering, IIT Kanpur (INDIA)
After the power market crisis of 2001, the Californian ISO (CAISO)
redesigned its electric energy market. It then introduced the concept of
available capacity (ACAP), whose objective is to allow the ISO to verify
in advance the availability of enough resources to satisfy the customer
load as well as reserves. In the new market structure, the energy market,
the ancillary service market and the congestion management market are
jointly optimized.
Voltage Control
The ISO procures reactive power support services on long-term
contracts from reliable must-run generating units. The actual short-term
requirement is determined on a day-ahead basis, after the real power
market is settled and the energy demand and schedules are known.
The generators are mandated to provide reactive power within the
power factor range of 0.90 lag to 0.95 lead.
02-03-2016 Side 31
Department of Electrical Engineering, IIT Kanpur (INDIA)
Frequency Control
Primary frequency regulation and secondary frequency regulation
are not mandatory services.
There exists up and down service regulation.
The costs associated with this service correspond to capital,
operation, fuel, and reduced efficiency costs, etc.
For secondary frequency regulation, the service must be available
in 10 min and should be supported for at least 2 hours.
The system operator calculates the quantity required of the service
according to a criteria that takes care of demand and contingency.
The quantity required generally comes close to 3% of the
maximum demand of the system.
02-03-2016 Side 32
Department of Electrical Engineering, IIT Kanpur (INDIA)
Primary FCAS Secondary FCAS VCAS Response
time Instantaneous 10min 1min
Duration Not limited 2h Without limit Provider Generators Generators Generation, transmission
and distribution companies
Monitoring Through Area Control Error (ACE)
In charge of system operator Transmission lines must operate according to the limits established by SO
Necessary amount
According to the system’s demand, between 5% and 12% demand, up and down
According to CAISO: more than 5% of hydraulic generation +7% of the other generation sources. Considering main contingencies
Determined by the SO according to voltage and reactive power levels
Commitment Optional Optional Mandatory to keep the pf between 0.9 capacitive and 0.95 inductive
Technical aspects of ancillary services provision in California
02-03-2016 Side 33
Department of Electrical Engineering, IIT Kanpur (INDIA)
Primary FCAS Secondary FCAS VCAS
Main costs
identified
Capital, fuel,
equipment lifetime
reduction,
maintenance and use
Capacity,
operation and
opportunity costs
Capacity and operation
Transaction
mechanism
Competitive auctions Competitive
auctions
Annual bilateral contracts
Payment to
providers
For capacity, usage
(spot price)
Capacity payment
and operation
payment for real
time dispatch
According to capacity and
use, only if its provision is
out of the requested PF
Customer’s
payments
According to project
demand
According to
project demand
According to CAISO
project demand
Price discovery For capacity, up: US
$16/MW, and down:
US $20/MW
For capacity US
$2.3/MW
Not specified
Economic aspects of ancillary services provision in California
02-03-2016 Side 34
Department of Electrical Engineering, IIT Kanpur (INDIA)
ASTRALIA ANCILARY SERVICE MARKET(AEMO)
02-03-2016 Side 35
Department of Electrical Engineering, IIT Kanpur (INDIA)
In order to best meet these challenges a new organisational
structure was developed:
ExchangeOperations
Market Development
Metering
Settlements
Settlement Residue
Registration
Prudentials
Power Exchange
Bidding
PASA
Optimisation (SPD)
Communications
Real time monitoring
Market Administration
Systems
Market Systems
Board and Executive
Corporate Services
Business Systems
Management and Support Services
ParticipantsJurisdictions End Users
Stakeholders
Power System Operation
Power System Dispatch
Power System Planning
Ancillary Services
Reserve Trader
System Operations
Services
• AEMO operates 8 separate markets for the delivery of frequency
control ancillary services (FCAS)
• purchases network control ancillary services (NCAS) and
system restart ancillary services (SRAS) under agreements with
service providers
02-03-2016 Side 36
Department of Electrical Engineering, IIT Kanpur (INDIA)
Australian Deregulation Process
• In Australia, the deregulation of the electrical system began in
1998. As part of this process, the National Electricity Market
(NEM) was created, in order to increase competition at every
stage of the electricity production and distribution.
• The National Electricity Market Management Company Limited
(NEMMCO) is the system operator and the ancillary services
market administrator .
• Initially, ancillary services were traded through long-term bilateral
contracts between NEMMCO and the services suppliers.
• Since 2001, frequency control ancillary services are traded in
competitive spot markets
• The payments are collected from customers only or from
customers and generators on a 50% to 50% shared basis
02-03-2016 Side 37
Department of Electrical Engineering, IIT Kanpur (INDIA) FCAS market • Through competitive bidding
• Payments include payments for availability and for the delivery of the
services
• normal operating band of frequency: 49.9 Hertz to 50.1 Hertz.
• Frequency control divided into two reasonably distinct subsets:
• Regulation:
• correction of the generation / demand balance in response to
minor deviations in load or generation.
• controlled centrally from one of AEMO’s two National Dispatch
and Security Centers.
• Provided through AGC action.
• Contingency:
• correction of the generation / demand balance following a major
contingent event such as the loss of a generating unit or a large
transmission element
• It’s a locally controlled action like, Generator Governor
Response, Load shedding, Rapid Generation.
02-03-2016 Side 38
Department of Electrical Engineering, IIT Kanpur (INDIA)
• Dispatch- based on merit order of cost.(i.e., The highest cost offer
to be enabled will set the marginal price for the FCAS category.)
• During period of high demand:
co-optimization algorithm is followed
(as it may be necessary for Dispatch center
to move the energy target of a scheduled
generator or load in order to minimize
the total [(of energy plus FCAS] cost)
02-03-2016 Side 39
Department of Electrical Engineering, IIT Kanpur (INDIA)
The FCAS offers and bids must comply with similar bidding rules
that apply to the energy market:
• Offers / Bids can consist of up to 10 bands with non-zero MW
availabilities;
• Band prices must be monotonically increasing;
• Band prices must be set by 12:30 on the day prior to the trading day
for which the offer/bid applies;
• Band availabilities, enablement limits and breakpoints can be rebid
under rules similar to those applying to the energy market.
• Ancillary service plant dispatched between an enablement limit and a
corresponding breakpoint can be moved in the energy market in order
to obtain more FCAS.
• For example, if a generator was dispatched between the upper
enablement limit and the upper break point, SPD may “constrain” the
unit in the energy market in order to obtain more FCAS, provided
this led to the lowest overall cost.
02-03-2016 Side 40
Department of Electrical Engineering, IIT Kanpur (INDIA)
NCAS • Voltage Control
• Synchronous Compensator: a generating unit that can generate
or absorb reactive power while not generating energy in the
market;
• Generation Mode: a generating unit that can generate or absorb
reactive power while generating energy in the market.
• Network Loading Control
• to control the flow on interconnectors to within short term
limits
• can be controlled through the use of Automatic Generation
Control or Load Shedding.
02-03-2016 Side 41
Department of Electrical Engineering, IIT Kanpur (INDIA)
System Restart (SRAS)
• Provided by two separate technology
1. General Restart Source: a generator that can start and supply
energy to the transmission grid without any external source of
supply.
2. Trip to House Load: a generator that can, on sensing a system
failure, fold back onto its own internal load and continue to
generate until AEMO is able to use it to restart the system.
02-03-2016 Side 42
Department of Electrical Engineering, IIT Kanpur (INDIA)
Payments • Both are long term contract ancillary services
• paid for through a mixture of:
• Enabling Payments – made only when the service is specifically
enabled
• Availability Payments – made for every trading interval that the
service is available.
02-03-2016 Side 43
Department of Electrical Engineering, IIT Kanpur (INDIA)
Primary FCAS Secondary FCAS VCAS Response time Between 6s and 60s 5min Instantaneous
Duration 90s Not specified Not specified Provider Generators with AGC Rapid generation
and load shedding Generators and syn. condensers
Monitoring Frequency monitoring. A range of 50+0.1 Hz is allowed
Performance testing and monitoring
Permanent monitoring of generators and reactive plants
Necessary amount
Determined by NEMMCO according to operational procedures
Determined by NEMMCO according to operational procedures
According to reactive power demand and energy consumption
Commitment Minimum is mandatory, optional provision is paid
Optional Mandatory to keep the pf between 0.9 capacitive and 0.93 inductive
Technical aspects of ancillary services provision in Australia
02-03-2016 Side 44
Department of Electrical Engineering, IIT Kanpur (INDIA)
Primary FCAS Secondary FCAS VCAS Main costs identified
Capital and opportunity Capital and opportunity Investments and operation
Transaction mechanism
Competitive offers mechanism managed by NEMMCO
Competitive offers mechanism managed by NEMMCO
Annual bilateral contracts
Payment to providers
According to the measured quantity provided multiplied by clearing price
Enabling and compensation
Payments for availability, enabling and compensation
Customer’s payments
According to ‘causer pays’ methodology, based on the contribution towards frequency deviation
Recovery is prorated over all participants. All payments for contingency raise and lower services are recovered from generators and customers
Payments by customers according to their load on pro rata basis
Price discovery The clearing price as determined by SPD. Bid cap US $20/MWh
The clearing price as determined by SPD. Bid cap US $30/MWh
US $0.2/MVArh
Economic aspects of ancillary services provision in Australia
02-03-2016 Side 45
Department of Electrical Engineering, IIT Kanpur (INDIA)
• Primary frequency regulation and voltage control services are
mandatory in all the studied markets, except for primary frequency
regulation in California.
• The response time demanded from the suppliers is directly related
with the price that the consumers pay for the service (faster response
is at higher price).
• The mechanisms used to manage the provision of the AS are bilateral
contracts or competitive offers
• The most important costs associated to frequency regulation
correspond to investments, operation, and reduced efficiency and
opportunity costs.
• Voltage control costs are mainly associated to investment, operation,
maintenance and opportunity costs.
Conclusions
02-03-2016 Side 46
Department of Electrical Engineering, IIT Kanpur (INDIA)
02-03-2016 Side 47
Department of Electrical Engineering, IIT Kanpur (INDIA)
Ancillary Service Market in India
02-03-2016 Side 48
Department of Electrical Engineering, IIT Kanpur (INDIA)
Proposed Ancillary Services in India
•Frequency Control Ancillary Services (FCAS)
•Network Control Ancillary Services (NCAS)
•Power Flow Control Ancillary Services (PFCAS)
•Voltage Control Ancillary Services (VCAS)
•System Restart Ancillary Services (SRAS)
02-03-2016 Side 49
Department of Electrical Engineering, IIT Kanpur (INDIA)
Frequency control ancillary Service
•IEGC band – 49.2 to 50.3 Hz
•Primary Response : FGMO
•Secondary Response :LFC/AGC (Absent by Design)
•Tertiary Response
•Availability Based Tariff (ABT)
•Use of Un-Requisitioned Surplus •Scheduled to the ‘POOL’
•Merit order
•Peaking Gas Stations
•Pumped Storage Plants
02-03-2016 Side 50
Department of Electrical Engineering, IIT Kanpur (INDIA)
Network Control Ancillary Services (NCAS)
Power Flow Control Ancillary Services (PFCAS)
• To maintain the power flow through an interface within the physical limit.
[FACTS controllers]
Voltage Control Ancillary Services (VCAS)
• Primary voltage control: Automatic local control [AVR, SVC]
• Secondary voltage control: coordinates the actions of local
regulators in order to manage the injection of reactive power within a
regional voltage zone
• Tertiary Voltage Control: manual optimization of reactive power flows
across the power system
• Activated under contingency situation
System restart ancillary services (SRAS)
02-03-2016 Side 51
Department of Electrical Engineering, IIT Kanpur (INDIA)
Execution of frequency support ancillary services
1. Eligibility Criteria
• All sellers and regional entities which are part of scheduling and
deviation settlement mechanism for real and reactive power.
• NOC issued by concern SLDC/RLDC to take part in power
exchange for participation in the ancillary service market.
2. Market Platform
• Through competitive bidding
3. Bidding and price discovery
• Window for bid in FSAS to be open after closure of DAM.
• Bids to be invited in a day ahead basis (time block wise bid with
quantum and price quote).
• Bid to be placed for standard time blocks of 2 hrs.
• Payment: pay as bid
02-03-2016 Side 52
Department of Electrical Engineering, IIT Kanpur (INDIA)
Time Line for Frequency Support ancillary service Market
1800 hrs-2000hrs
• Bid call session
• Closed Double Sided Bidding
• Members can Submit, edit, modify, delete buy & sell bids
2000hrs -21.00hrs
• PX to provide information to the nodal agency
• Combined stack bid to be prepared by the nodal agency based on bids received from PXs.
2200hrs
• Scheduling
• Once dispatch decision is taken, PXs to calculate area clearing price based on transmission network available.(Pays IN)
D+1
• Accounting and settlement
• PX makes payment to bidders in proportion of the quantum of overdrawal. (Pays OUT)
02-03-2016 Side 53
Department of Electrical Engineering, IIT Kanpur (INDIA)
Dispatch of FSAS bids in real time
•If the frequency remains 0.05 Hz below the lower operating frequency
range as specified in the IEGC for two consecutive time-blocks, the
nodal agency to give instructions to the FSAS provider to despatch in the
third time block for despatching generation from the fifth time block.
• If the frequency remains at 50.0 Hz for two consecutive time blocks,
after kicking-in of the FSAS, the nodal agency to give instructions for
withdrawal of FSAS.
• The generation despatched under FSAS would be given a despatch
certainty for 8 time blocks (i.e. 2 hours).
• In case withdrawal instructions are given by the nodal agency before
the completion of 2 hours, 50% of the bid price to be paid to the seller
for the period falling short of 2 hours.
• Further, in case a seller, whose power has been scheduled, fails to
provide the committed generation in real-time then the seller would be
liable to pay 1.5 times the bid price or the applicable UI rate whichever
is higher.
02-03-2016 Side 54
Department of Electrical Engineering, IIT Kanpur (INDIA)
•No commitment charges payable to the bidders for making itself
available in the FSAS market.
•Upper limit of UI rate to be the ceiling price for the scheduled bid.
•The energy despatched under FSAS would be deemed to be delivered at
the Regional periphery.
•Any over injection by the FSAS provider shall not be paid for.
NODAL AGENCY: NLDC
02-03-2016 Side 55
Department of Electrical Engineering, IIT Kanpur (INDIA)
Voltage Control Ancillary Services (VCAS) Execution
•To be through PX.
•Payment to be made on pay-as-bid subject to maximum ceiling rate of
reactive energy.
•Payment to be as per regulation 6.6 of CERC (IEGC) Regulation, 2010.
NODAL AGENCY: NLDC
Execution of Black Start Ancillary Services (BSAS)
•The generators to be paid for one day capacity charges on the day of
providing the BSS, as determined by the Commission.
•The energy charges to be paid at twice the energy charges determined
by the Commission for the volume of energy supplied during the
restoration process.
•Other flexible generators providing BSAS to be paid fixed and energy
charges on the normative figure to be specified separately.
NODAL AGENCY: NLDC
02-03-2016 Side 56
Department of Electrical Engineering, IIT Kanpur (INDIA)
Issues
• Need for ancillary Service
• Payment Risk
• Linkage to the UI ceiling Rate
• Possible Breach of PPAs
• Load Management by Utilities
• Market Design
• Commitment Charge
• Forecasting
02-03-2016 Side 57
Department of Electrical Engineering, IIT Kanpur (INDIA)
Points of concern • How would FSAS be incentive compatible?
• Will FSAS act as a cheaper alternative than UI for grid indiscipline?
• Pay as Bid Vs Uniform Price Auction?
• Since, bids for FSAS market would open after the DAM closes, the
‘owners’ of capacity would prefer to sell electricity in the DAM first
and offer unsold capacity in for FSAS market. Clearly, supply side
would have less flexibility to address the needs of FSAS market. It is
important to make demand side bidding an integral part of the FSAS
mechanism.
• FSAS as a Substitute for UI Mechanism?
• Can be used as a option market along with UI mechanism.
• Develop it further to augment/replace UI mechanism in future
• Sharing of Revenue from FSAS
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Department of Electrical Engineering, IIT Kanpur (INDIA)
• Criteria for deployment and withdrawal of FSAS
• Reduce Bid Span Granularity
• Need for Effective Market Monitoring
• Uncertainty of Despatch and Commitment Charges
• Payment to plants "identified to be despatched" or
"despatched"
02-03-2016 Side 59
Department of Electrical Engineering, IIT Kanpur (INDIA)