Home

Power Exchange Code User Guide Draft

1. How Are Settlement Quantities Determined Paragraph 56 specifies an equivalent calculation for Purchasers 56 Energy Charges HTSO shall calculate for each Dispatch D ay in respect of each Participant Purchaser with Load a daily Energy Charge in respect of such Load in accordance with the following equation 24 po 2 50 SMP where the Settlement Q uantity for Participant Purchaser p in Dispatch Hour t supplying Customers in Greeceis calculated in accordance with the following equation SQ Y MQ 1 TLFP and where the Settlement Quantity for Exporting Purchaser p in Dispatch Hour t is calculated in accordance with the following equation SO Y DAQ I TLFP Meter Quantities are calculated in section X of Schedule i e paragraphs 39 to 43 Paragraph 42 specifies that Meter Quantities must be based on Settlement Quality Meter Data which is appropriately aggregated over the meters corresponding to the Participant concerned and appropriately adjusted to account for Distribution Embedded Units and Eligible Customers connected to the network Paragraph 43 specifies the conditions under which Settlement Quality Meter Data values of auxiliary Load equipment may be netted from those of Units Paragraph 41 specifies the means by which unprocessed Metering Data is processed so as to be Settlement Quality M eter Data Day Ahead Quantities are determined in accordance with section XI of Schedule
2. Naa How Are SMPs Determined 10 HOW ARE SMPS DETERMINED The System Marginal Price SMP in each Dispatch Hour reflects the marginal cost of meeting actual demand on the system given actual generation availability in that hour The SMP is calculated ex post ie after the Dispatch has occurred in a separate calculation SMPs are calculated based on the Offers submitted by Generators actual Unit availability and actual Load In the event of suspension of the STA SMPs are set to an Administered Price SMPs are calculated after the Dispatch has been completed and after Meter Quantity data has been determined They are calculated on the Calculation Day the day five days after the Dispatch Day The rules for the determination of SMPs are specified in section XII of Schedule B of the Power Exchange Code paragraphs 46 to 53 Paragraph 48 is the principal paragraph specifying the methodologies and principles that Pricing Software must comply with 10 1 Calculation of SMP The main provisions of paragraph 48 are as follows SMPs are computed as a result of a calculation of an unconstrained schedule of the system using actual Unit Offer parameters as assumed in the Dispatch as inputs Thelevel of load assumed is the total MWh of actual Meter Quantity load determined for that hour over the interconnected transmission system The calculation of the ex post unconstrained schedule and the determination of SMP from this
3. Paragraph 75 of Schedule B specifies the treatment of Special Unit costs HTSO so as to comply with the Law makes additional payments to Special Units equal to the difference between the amounts specified in the Law and the payments they otherwise receive under the Power Exchange Code for energy Since these additional payments may not always equal the charges the HTSO is authorised by RAE to recover from Participants in respect of Special Units in a month the HTSO will need to arrange for the appropriate accounting and banking facilities as required so as to account for and manage the difference on an on going basis Section XIV of Schedule B specifies the rules for Constrained On Payments and Constrained Off Payments The treatment of these payments is also described in section of this document Losses adjustments are net payments received by the HTSO since because of the effect of using marginal Transmission Loss Factors in the calculation of Settlement Quantities refer to section 12 of this document total Energy Charges will normally exceed total Energy Payments As described above Paragraph 59 specifies a transfer from the Energy Sales and Purchases Account to the Uplift sub account for losses by the amount of the difference Paragraph 78 relating to Interconnector net costs also modifies the Uplift sub account for losses but since the effect of this paragraph is to make a transfer between two Uplift sub accounts there is no
4. approval of the Operating Code and Power Exchange Code approval of the transmission control agreement regulation of prices dispute resolution etc The operation of these new regulatory arrangements will be crucial to ensuring the effective operation of the new market arrangements and in particular to ensuring that independent generators and suppliers are treated in a fair and non discriminatory way ESB INTERNATIONAL nera sees 4 e Ta 2 Framework of Codes and Agreements 3 FRAMEWORK OF CODES AND AGREEMENTS 3 1 Overview The new electricity industry structure in Greece will allow participation by independent generators and suppliers and it is necessary that their participation is permitted on a non discriminatory and competitive basis To ensure this it will be necessary that some things that were previously carried out as actions internal to PPC are now established as arms length commercial transactions even where the parties may be different parts of PPC As noted in the previous Chapter new regulatory arrangements are being put into place to ensure that this new structure works effectively These changes mean that it is necessary to introduce a number of new agreements Codes and other instruments in addition to the Power Exchange Code and the purpose of this Section is to provide a review of all these provisions Partly these instruments are required for commercial reasons to ensure that
5. ESB INTERNATIONAL What Does N et Settlement M ean Figure 6 6 Example N et Imbalance Hourt 2 Load Net Gen Load Net Gen Gen MW uw Gen MW A 300 250 50 400 350 50 B 200 250 50 300 350 50 500 500 700 700 0 Supplier A is paid DRS 1 100 000 50 10 000 50 12 000 by the HTSO and Supplier B is charged DRS 1 100 000 50 10 000 50 12 000 The practical effect of this least cost Dispatch and net settlement with respect to ownership is that to the extent a Supplier can meet its customers energy requirements from purchases through the STA more cheaply than by producing itself it will do so The transactions for obtaining the necessary imbalance energy are embedded in the trading arrangements In this example Supplier B purchased energy in both hours from Supplier A and in doing so lowered the total system cost from what it would have been if it had generated sufficient energy to cover all its own load BLOK T asas MS 32 ESB INTERNATIONAL How do Bilateral Contracts Work 7 HOW DO BILATERAL CONTRACTS WORK SMPs fluctuate according to market conditions Participants if they desire make bilateral contracts between one another to lock in the price at which imbalance energy is bought and sold so as to removethe financial uncertainty of paying or being paid the SMP For example in the preceding illustration Supplier B buys 5
6. Step 1 is In Merit Steps 2 amp 3 are not 62 2 5 Step 2 MW 1 1 Minimum Dispatch Capability Maximum Dispatch Capability MNDC MXDC Paragraph 62 3 of Schedule B specifies the formula for determining how much of the second step of a Unit s Offer pricefunction is in merit Mu ESB INTERNATIONAL nera sess 5 AAKE How do Constrained On Off payments Work 623 Thein merit capability of the second step of the Offer Price Function of a Unitin a Dispatch Hour shall be calculated in accordance with the following equations If OP lt SMP then IMC Min OQ MXDC IMC a otherwise 0 wheret is Dispatch H our that falls within Dispatch D ay d and where M XD Cu is the maximum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC BError Reference source not found In the following illustration all of the Offered capacity of step 2 of the Offer price function is in merit because the Offered price of step 2 is less than SMP Figure 13 Offer Price Function of a Unit DRS MWh Steps 1 amp 2 are In Merit Step 3 is not PEC B62 3 SMP smssumssmussuusuuasuanuusauusuuuumauuussurcuacrasscuususauuaamccrcruas MW f f Minimum Dispatch Capability Maximum Dispatch Capability MNDC MXDC Paragraph 62 4 of Schedule B specifies the formula for determi
7. 1 Suppliers authorised in accordance with the Greek Electricity Law to sell electricity to final customers in Greece and 2 Exporting Purchasers that purchase electricity in the STA for the purpose of export from Greece to supply customers in another country A Supplier is an entity authorised to carry out the function of electricity supply to Eligible Customers including importation of electricity by an Eligible Customer for its own use or in the case of PPC electricity supply to Non Eligible Customers PPC has an exclusive right and an obligation to serve Non eligible Customers Other Suppliers have the right to serve Eligible Customers and PPC has the obligation to serve Eligible Customers if they are not served by other Suppliers To bean Exporting Purchaser it is assumed that an entity must also be a domestic Generator see below Special rules limit the amount of energy an Exporting Purchaser can export 4 12 Generators The category Generators comprises 1 domestic generating entities owning power plants located in Greece and holding an Electricity Generation Authorisation and 2 foreign generating entities owning power plants located outside of Greece where they hold a Greek Electricity Supply Authorisation The use of the term Purchaser is used only to ensure clarity in the Trading Arrangements and it is not intended that this is a new category requiring a special authorisation in its own right As explained in the
8. CONP Max 0 0P SMP 1 TLFG CONC ueg s l uts wheret is a Dispatch Hour that falls within Dispatch D ay d where Unitu is located at Node i where ueg signifies that the summation is made for each Unit u that according to its Registered Information is owned by Participant G enerator 9 and where HTSO in order to fairly account for the effect of Distribution Loss Factors of Distribution Embedded Units may in accordance with the terms of its authorisation appropriately adjust the equation in respect of a Distribution Embedded Unit so as to account for a Distribution Loss Factor ESB INTERNATIONAL nera sees AAKE How do Constrained On Off payments Work In the following illustration Constrained On Payments equal to the black shaded area are made in respect of the Unit for the Dispatch Hour In this simplified illustration the effect of Transmission Loss Factors has been ignored Figure 11 12 Offer Price Function of a Unit DR Wh SM Constrained On Payment in this Dispatch Hour I 77 I I I 1 SMP Step 3 MW f Minimum Dispatch Capability Meter Quantity MNDC MQ Paragraph 69 provides for additional Constrained On Payments if the Unit in question was instructed by the HTSO to start up and synchronise and the payments for energy plus Constrained On Payments and Constrained Off Payments above do not cover the Offered costs represe
9. Determine Meter Quantities Determine SMP Calculate settlement amounts Issue bills amp statements Day Ahead Dispatch Funds transfer HTSO sends out schedules to Generators and publishes forecast SMPs Each Dispatch Hour 24 Dispatch Hours in a Dispatch Day See Figure 2 4 Dispatch Hour 0 00 DA SA Day Ahead After the Dispatch Day See Figure 2 2 Day Ahead Dispatch Day See Figure 2 3 Dispatch Day See Figure 2 5 Metering amp Figure 2 6 Billing amp Settlement 4 3 1 Timeline D ay A head During the day ahead of Dispatch the HTSO produces two forecast schedules for electricity production for the following day an unconstrained schedule and a constrained schedule Generators offer their energy and in each of the schedules the HTSO accepts the cheapest Offers necessary to match its forecast of demand including transmission losses plus scheduled exports for the following day The Offers of Generators specify price and quantity parameters to describe their availability In determining the forecast schedules the HTSO does not take into account the contract positions of Participants The first of the schedules also ignores the effect of transmission constraints and is thus known as unconstrained Itis produced so as to determine a single forecast SMP for Greece for each hour of the Dispatch Day Forecast SMPs are set at the Offer prices of the m
10. TheHTSO will bethe key institution in facilitating the entry into the market of independent generators who are also permitted to compete directly for sales to certain customers termed Eligible Consumers This new structure is summarised in Figure 2 1 ESB INTERNATIONAL nera sees e Ta 2 The N ew Industry Structure Figure 2 1 N ew Industry Structure PPC Generators Eligible Customers Eligible Customers PPC Transmission m Distribution System Operator Eligible Customers PPC Distribution and Supply Eligible Customers Non Eligible Customers Electricity Flow Commercial transaction The key feature of this new structure is the distinction that is created between the different sectors of the electricity industry generation where competition is permitted between different generators transmission wires where there remains a natural monopoly in the ownership of PPC distribution wires where there remains natural monopoly the ownership of PPC supply sales to customers which is opened to competition initially to a limited category of Eligible Customers ESB INTERNATIONAL The N ew Industry Structure 2 2 TheNew Entities and their Functions In this new structure the main entities and their functions are as described below HTSO Theorganisation has been created to take
11. Codes the category of Participant covered by the term Purchasers comprise entities that hold either a Supply Authorisation or a Generation Authorisation in the case of an Exporting Purchaser This point can be further clarified through the use of appropriate terminology when the Trading Arrangements are translated into Greek A 15 E ESB INTERNATIONAL nera sees Summary of System Trading Arrangements All domestic Generators are required to hold Electricity Generation Authorisations under the terms of Article 9 of the Greek Electricity Law Thereis no requirement that all domestic Generators must also be Suppliers However all Suppliers must also be Generators in addition to being Purchasers every authorised Supplier must own adequate generating capacity in accordance with the Greek Electricity Law It must also provide long term confirmation as to the necessary arrangements for reserve generating capacity in accordance with the Greek Electricity Law In addition a Supplier that provides energy from generating capacity located in another country must arrange the necessary transmission capacity for the transmission of electricity 4 1 3 Non Interconnected Islands Entities either generating or consuming energy on the non interconnected islands do not participate in the STA Such an entity will only participate if and when the island it is located on is joined to the interconnected transmission
12. Greece or another EU country sufficient to meet the demands of their contracted consumers It is likely that in most cases generators will also operate as suppliers Eligible Customers these will initially be limited to the very large customers many of them connected directly to the transmission system As competition is allowed to expand eligibility would be expanded to include more customers Non Eligible Customers these will continue to have to purchase all their requirements from PPC ESB INTERNATIONAL nera 285 e Ta AAKE 2 The N ew Industry Structure Renewable Generators are the subject of special arrangements under the Law through which they contract directly with the HTSO The terms of these special arrangements are specified in the Law and are related to tariffs Any extra costs incurred over the cost of conventional generation will be recovered by the HTSO through the Uplift arrangements in the PEC described later in this Guide 2 3 Regulatory Arrangements An important part of these new arrangements is the creation of a new regulatory agency for the industry the Regulatory Authority for Electricity or RAE This organisation is given responsibility for regulation of many of these new competitive activities under the auspices of theMinistry of Development Together they are responsible for issuing of authorisations to the HTSO to the transmission distribution generation and supply entities
13. applicable and to monitor their compliance with these on an on going basis It is not the responsibility of the HTSO to apply penalties or other sanctions on Suppliers that are not compliant with respect to their Authorisations The HTSO is responsible for reporting the nature of any non compliance to the RAE and it is an on going responsibility of the RAE to determine the consequences to the Suppliers concerned on a case by case basis Consequently penalties for non compliance in respect of Electricity Supply Authorisations are not contained the STA 7 TheHTSO does however require that the authorised capacity runs if called upon and given a reasonable and pre determined recall period in the event of System Emergency Conditions or System Critical Conditions This requirement and the consequence for non compliance in these situations are described in the Codes 35 ESB INTERNATIONAL 485 f Ora m Nus How Does HTSO Ensure A dequate Available Capacity 9 HOW DOES HTSO ENSURE ADEQUATE AVAILABLE CAPACITY It is the HTSO s responsibility to ensure that adequate generating capacity is available so as to meet its system reliability requirements The System Trading Arrangements are designed to givethe HTSO the mechanisms it needs so that it can arrange this necessary capacity and the System Trading Arrangements are also designed to encourage Participants to have incentives consistent with the H TSO s responsibilities
14. between the HTSO and the transmission company is specified in the Law and the new requirement for authorisations for the different entities is also specified in the Law along with provisions on the authorisations content etc A number of other agreements have been prepared as part of this project work and thought they are not individually specified in the law they are important parts of the new framework transmission connection agreement transmission use of system agreement ancillary services agreement In the following section we provide summaries of each of these documents 32 Summary of the Codes Agreements and Authorisations The Power Exchange Codeis dealt with in more detail later in this Guide and the Operating Code is the subject of a separate Guide Below we summarise the objectives parties coverage and key points of all the other documents referred to above 3 2 1 The Transmission Control Agreement There will be a single Transmission Control Agreement TCA between the HTSO and the transmission owner PPC s TBU and Table 3 1 summarises the main elements of the proposed document Though it will be a commercial agreement rather than a Code applied by Law the Law requires that its terms be approved by the Minister RAE ESB INTERNATIONAL nera seve E e Tia AAKE 2 Framework of Codes and Agreements Table 3 1 Summary of the Transmission Control Agreement Type of Document Comme
15. by the HTSO and neighbouring control area operators in the event of unexpected transmission system conditions and if it is agreed and necessary to do so in order to preserve reliability 14 5 Metering The HTSO does not require meter readings from Units in foreign countries or Exporting Purchasers in order to determine Meter Quantities for settlement of international trade rather it uses the quantities accepted in the constrained forecast generation schedule adjusted for transmission losses as described in section 14 6 The HTSO is required to have installed a multi function meter capable of measuring the net energy transfer on each international interconnector for each one hour period The HTSO is responsible for obtaining hourly readings from these meters ESB INTERNATIONAL nera 3595 Ga Ora were Nus How Arelmports Exports Handled 14 6 Settlement Participants are paid the SMP adjusted for transmission losses for their energy quantities accepted in the constrained forecast generation schedule for their Units located in foreign countries Exporting Purchasers pay the SMP for their energy quantities adjusted for the cost of transmission losses accepted in the constrained forecast generation schedule HTSO determines where energy imported and exported is nominally delivered to or taken from the Greek transmission system in accordance with Parargraph 44 44 Designation of Import N odes and Export N odes 18 For the
16. determining Metering Data Settlement Quality Metering Data Meter Quantities Day Ahead Quantities and Transmission Loss Factors The following diagram is an illustration of the sections of the Power Exchange Code in which the factors that comprise Settlement Quantities are specified lt Accounting for Energy Sales and Purchases 8 9 i Para 55 Para 56 i Energy Payments Energy Charges i and Settlement Quantities for Gens and Settlement Quantities for Purch s i E A E i i Para 42 Para 45 i Determination of Meter Quantities Determination of Day Ahead Quantities 1 1 xu i 5 41 Operating Code Determination of Settlement Wee ae ee el A Quality Metering Data Para 43 Netting of Settlement Quality Meter Data NM 6 Interrogation of Meters et al 5 5 1 1 i N 1 1 Other provisions of Section Il and Operating Code Paragraph 54 of Schedule B of the Power Exchange Code specifies that on each Calculation Day the HTSO records in each Participant s account the revenues and costs for energy sales and purchases through the trading arrangements 54 Timing of Calculation of Daily Settlement A mounts On the Calculation Day HTSO shall calculate Energy Payments and Energy Charges for each Participant for each Dispatch Hour of the Dispatch Day in respect of that Cal
17. entered into by players in the newly restructured industry and the relationships between those documents and the relationships between the players A summary description of the System Trading Arrangements STA used to establish the arrangements for trading wholesale electricity in Greece in particular this section describes the rules for how Suppliers serve the load of their final customers how other generators in Greece can participate in the trading arrangements and how energy for export is purchased and e A summary description of the workings of the Greek Power Exchange Code The second part of this document is a series of responses to frequently asked questions about the market structure This part answers the following questions What does net settlement mean How do bilateral contracts work e How does the HTSO ensure adequate installed capacity e How does the HTSO ensure adequate available capacity How SMPs determined e How do Constrained On and Constrained Off Payments work e How are Settlement Quantities determined e How areAncillary Services handled How areimports exports handled and e What charges and payments are settled under the Power Exchange Code The purpose of this document is to be descriptive It is supplemental to the main deliverable of Task 3 of the HTSO establishment project being the Detailed Definition and Description of Electricity Trading System Arrangements in Gr
18. in this regard 9 1 HTSO Mechanisms The HTSO has several processes with which it can collectively arrange adequate available capacity including day ahead scheduling process the process of contracting for Ancillary Services and the generator outage co ordination process The day ahead scheduling process occurs once a day seven days a week to produce forecast generation schedules for both energy and Ancillary Services and to forecast SM Ps for each hour of the following day on the basis of the Offers received Having made Offers day ahead Units that are in Greece and are scheduled day ahead in the constrained schedule are committed to providing their offered capacity in accordance with their offered price and quantity parameter submissions and within the limits of their technical parameters specified in their Registered Information if called upon by the HTSO to run in the Dispatch Day The HTSO thus relies on Units scheduled day ahead to be available for the following day and schedules sufficient capacity including Operating Reserve so as to factor in Load forecast error forced outages and other uncertainties that may occur on the day On a longer term basis the HTSO can enter into Ancillary Services contracts to ensure that sufficient Operating Reserve is available in the day ahead scheduling process Ancillary Services contracts can specify minimum availability conditions and other conditions such that the H
19. obligation to obtain an Electricity Generation Authorisation in accordance with Article 10 of the Greek Electricity Law are represented in the STA by the Special Participant e Very small supply entities exempt from the obligation to obtain an Electricity Supply Authorisation in accordance with Articles 24 3 and 24 4 of the Greek Electricity Law are represented the STA by the Special Participant The net cost of the Special Participant if any is passed through to Participants as part of an Uplift charge e e 5 m aem ESB INTERNATIONAL 4 nera sees Summary of System Trading Arrangements payment is sent In respect of Participant ownership therefore the HTSO conducts net settlement Sections this document illustrate transactions that can be made in the STA both in the case of a Supplier where the Purchaser and Generator are owned by the same parent entity and in the case of a bilateral contract where a Purchaser has contracted with a third party Generator 4 3 Summary of STA Timeline The STA consists of five steps These steps are summarised in the remainder of this section 1 The first step is a day ahead forecast Generators make Offers the HTSO makes load forecast and Exporting Purchasers schedule exports for the following day From this data forecast generation quantities forecast SMPs and international interconnector schedules are calcu
20. over PPC s functions in respect of system planning system development and system control with PPC remaining responsible for actually carrying out development work and physical operation The HTSO will also have responsibility for the new activities of granting access to system users and the operation of the new trading arrangements The HTSO will be established in a way that is intended to ensure its independence from undue influence by PPC or independent generators or suppliers PPC Continues to be responsible for all the existing generation plants and for the ownership and physical operation of the transmission system and the distribution system For accounting and regulatory purposes PPC is unbundled between e generation transmission distribution supply Independent G enerators these will be authorised to sell power in Greece providing they are located in the EU and satisfy all necessary environmental etc requirements They will participate to the full extent of their output in the system trading arrangements Independent generators can sell into Greece even if they are located outside of Greece providing they are located in the EU and can obtain access to inter connectors and all other necessary transmission capacity Independent Suppliers these will be allowed to compete to sell power to Eligible Customers Such suppliers cannot simply be traders as the Law requires that they are the owners of generating capacity in
21. schedule are made in the same way the forecast unconstrained schedule and forecast SMP are determined day ahead but the calculations are independent In producing the ex post unconstrained schedule the HTSO schedules Unit Offers so as to minimise the offered Cost of total load including losses taking into account the following factors the price and quantity parameters of all Offers received in respect of Units in Greece the actual maximum net availability of each Unit in Greece in the Dispatch Hour concerned exclusive dispatch arrangements for Special Units and Indigenous Fuelled Units Operating Reserve requirements transmission system losses incorporating any regional differences the actual flows interconnectors and ESB INTERNATIONAL How Are SMPs Determined the technical parameters of Units as set out in their Registered Information otherwise advised The HTSO does not take into account transmission constraints in the calculation of the ex post unconstrained schedule Conceptually the SMP in each Dispatch Hour is set as being equal to the point at which the supply curve for energy meets the demand curve for energy Figure D etermination of SMP 100 100 100 100 100 100 100 100 100 100 100 100 MW MW MW MW MW MW MW MW MW MW MW MW a Quantity MW Price DRS MW SM 1 More specifically the SMP in ea
22. the lexicon of other restructured electricity sectors around the world are An Independent System Operator and independent arket Operator ISO and PX The HTSO is responsible for both system and market operations and is fully independent from PPC in accordance with the EU Directive e An Offer based Dispatch Scheduling and Dispatch of generating Units is based on Offers received by the HTSO for the full declared available capacity of those Units The HTSO conducts a security constrained least cost Dispatch of all offered generating capacity and does not take into account any contract positions of generators in its Dispatch of the system Contracts between market partici pants are therefore financial rather than physical in nature A single price for imbalance energy A unique price of energy SMP is set for the entire interconnected transmission system in every hour ie prices are not locational The SMP in each hour is determined in principle by the marginal Offer cost of supplying an additional MW of energy to the system ESB INTERNATIONAL nera sees 5 ALKE e Summary of System Trading Arrangements SM Ps determined once for each hour The STA consists of single and separate market in each hour in which prices and quantities are determined after the fact ie ex post on the basis of actual generator availability and load conditions Restrictions on Offer prices The Energy Regulatory Autho
23. the transactions take place on a commercial basis and partly the instruments are required for regulatory reasons Though this new framework may appear complex experience elsewhere has demonstrated that these or similar instruments are necessary to make the new industry structure work effectively Figure 3 1 illustrates the hierarchy of Laws Codes and agreements that will be required Figure 3 1 The Framework of Law Codes Authorisations and Agreements E U Directive Greek Electricity Law HTSO dransmssion Transmission Supply Generation Operating Power Authorisation Control Authorisation Authorisation Authorisation Code Exchange Agreement Code i Ancillary Connection Use of System Agreements Agreements Services Agreements The EU Directive is the driving force for much of the structural change and implementation of the Directive has now been written into the new Greek Electricity Law The Law itself refers to anumber of the Codes agreements and other instruments in particular BLOK T Feet 7 ESB INTERNATIONAL Framework of Codes and Agreements the Power Exchange Code the Operating Code both specified in the Law including their coverage and provisions for their preparation and approval the Transmission Control Agreement that sets down the relationship
24. use an interconnector and made in accordance with the Participant s rights to transmit energy from the Unit to the interconnector The only difference between an Offer made in respect of a Unit located outside of Greece and a Unit located in Greece is that there is no Offer price restriction on Units located outside Greece This isin view of the practical difficulties of auditing the costs of generating plants located in foreign countries 14 3 Scheduled Interconnector Flows Offers in respect of Units in foreign countries and valid export nominations are taken into account in both the unconstrained forecast generation schedule and the constrained forecast generation schedule Offers in respect of Units in foreign countries that are accepted in the constrained forecast generation schedule and all valid export nominations are accepted by the HTSO and aggregated into a single scheduled interconnector flow for each hour for each interconnector so long as the net scheduled quantity represents a feasible flow on the interconnector with respect to its available transfer capacity as determined by the HTSO after taking into account the HTSO s need to reserve some portion of the capacity of the interconnector to meet its system security obligations 63 ESB INTERNATIONAL 5 nera sess How Arelmports Exports Handled confirmation has been received from the adjoining system operators that arrange
25. which prices are set the way in which HTSO s costs are recovered from Participants how invoices and remittances are calculated how payments and charges are made and it also covers the timing of each activity FigurebP illustrates the main sections of Schedule B ESB INTERNATIONAL 2505 Ea era AAKE Wag Summary Description of Power Exchange Code Figure5 2 Contents of Schedule B of Power Exchange Code B I Conventions B II Responsibility for Energy M etering B Ill Other Registration Information and HTSO Responsibilities B IV Offers Load and Price Forecasting Scheduling and Dispatch V Special Provisions Relating to International Trade B VI HTSO Settlement Responsibilities B VII Settlement Timeline B VIII Settlement Variables B IX Determination of Loss Factors B X Determination of M eter Quantities B Determination of Day A head Quantities XII Determination of System Marginal Prices B XIII Determination of Energy Charges and Energy Payments B XIV Determination of Constrained On and Off Payments B XV Ancillary Services B XVI Other Charges and Payments B XVII Determination of Uplift Charges B XVIII Settlement of Transmission Charges B XIX Settlement Statements B XX Invoices B Compliance B XXII Suspension of Procedures B XXIII Information M anagement 5 4 Schedules C and D Schedule C sets out the form of a Person s address and
26. would from time to time identify need perhaps on a regional basis and open contracts for bidding and select the least cost tender However for as long as PPC dominates the industry the prices paid by HTSO for such contracts would be cost regulated If there were some profit component in those regulated prices then that would also be determined on some standard regulatory basis Independent generators would choose whether or not to sign these regulated contracts and in the long run it is envisaged that contract prices would be set by competitive tender For mandatory Ancillary Services that HTSO pays for HTSO would sign contracts with generators and the prices paid by HTSO for such contracts would also be cost regulated Participants with agreements to provide Ancillary Services declare their capability to provide each contracted Ancillary Service by 12 00 of the day immediately preceding the Dispatch Day It is the responsibility of each Participant to ensure that such declarations comply with the terms of its Ancillary Service Agreements When HTSO determines the Generation Schedule for the following Dispatch Day it makes an initial selection of hour to hour providers of energy and Ancillary Services from those sources available adhering to the principles of a least cost and security constrained ESB INTERNATIONAL ie DE e nera How AreAncillary Services Handled operation of the system and in accor
27. 0 MW in each hour of the illustrative day at the SMP To the extent the SMP rises or falls Supplier B s costs rise and fall Yet Supplier B might have little influence over the market conditions that cause movements in the SMP Its costs are capped because Suppliers are obliged to own enough capacity to cover their load Supplier B s costs can never exceed its own production costs of DRS 12 000 MWh from Unit B2 But Supplier B may wish to enter into a contract with Supplier A or perhaps an independent Generator that is not a Supplier to lock in its cost for imbalance energy at a lower price The form of contract that Participants can enter into for this purpose is a Contract For Differences CFD A CFD is a financial contract between the parties to the bilateral transaction and is independent from the HTSO A CFD has a strike price and a MW quantity In its most simple form it specifies that when the SMP is higher than the strike price the Generator pays the Purchaser the SMP minus thestrike price multiplied by the CFD MW quantity for that hour and when the SMP is lower than the strike price the Purchaser pays the Generator the strike price minus the SMP multiplied by the CFD MW quantity for that hour The financial effect of a CFD therefore is that both the Generator and the Purchaser receive a guaranteed net price the strike price at which they respectively sell and buy the CFD MW quantity of imbalance energy The ex
28. 00 of the day prior to the Dispatch Day Exporting Purchasers do not nominate a maximum price they are prepared to pay to purchase this energy they only nominate a quantity to export for each Dispatch Hour The limit on the amount of capacity that can be exported with respect to the authorisation of the Generator is monitored by the HTSO but any consequences of non compliance is an RAE matter and is outside of the STA ESB INTERNATIONAL nera sees 5 ALKE e How Arelmports Exports Handled 14 2 Units in Foreign Countries Entities with generating Units located in another country may import energy into Greece for the purposes of supplying customers In order to import energy across an interconnector the entity must be an Authorised Supplier and meet the required technical requirements to import energy to Greece In particular the entity must hold rights to use interconnector capacity into Greece the methods by which Participants may obtain rights to use interconnector capacity into Greece are outside of the STA and arrange with system operators outside of Greece for the delivery of energy from its units to Greece To import energy into Greece from a Unit outside of Greece a Participant must submit a Daily Offer for the Unit by 12 00 of the day prior to the Dispatch Day just as it would if the Unit was located in Greece However the Daily Offer must be made in accordance with the Participant s rights to
29. 9 2 which had a credit balance as of the end of the Calculation Day in respect of the last calendar day in the month by an amount equal to that credit balance and debit each Participant Purchaser s Participant Trading Account an amount equal to that determined pursuant to PEC B84 for that Participant Purchaser In addition to Uplift Paragraphs 76 and 77 of Schedule B specify rules for the treatment of renewable and or cogeneration entities on the Non Interconnected Islands Payments and or charges to these entities are similar to those in respect of Special Units and the HTSO is responsible for their management and settlement These payments and charges are separate from Uplift because the entities concerned are either not Participants or are not acting in the capacity as Participants 15 3 Transmission Section XVIII paragraph 86 of Schedule B specifies the way in which transmission charges determined in accordance with Transmission Connection Agreements and Transmission Use of System Agreements and transmission payments determined in accordance with the Transmission Control Agreement are transacted through the HTSO settlement accounts Since the transmission payments may not always equal transmission charges the HTSO ina month the HTSO will need to arrange for appropriate banking and accounting facilities as required so as to account for and manage the difference on an on going basis Charges in respect of entities that ha
30. B i e paragraphs 44 and 45 which refer to the provisions of the Operating Code for accepting Offers in respect of Units in foreign countries and accepting export Nominations Section Il of Schedule B and in particular paragraph 6 specify the terms under which Metering Data is obtained ex 59 e Lud ESB INTERNATIONAL Jj sees 5 AAKE How AreAncillary Services H andled 13 HOW ARE ANCILLARY SERVICES HANDLED Ancillary Services are those services other than the production of energy required to maintain a stable frequency and voltage on the transmission system The HTSO is responsible for procuring and using these services in its scheduling and dispatch of generation and in its use of the transmission system All costs incurred by HTSO in procuring Ancillary Services are passed on to Participants through Uplift The Operating Code specifies certain mandatory Ancillary Services HTSO procures other Ancillary Services through Ancillary Service Agreements with individual Participants These agreements specify the obligations of Participants to provide Ancillary Services and the terms by which they are paid including payment for some mandatory Ancillary Services Ancillary Services for which Participants sign agreements are Automatic Generation Control Operating Reserve Contingency Reserve Reactive power Black Start For each type of non mandatory Ancillary Service HTSO
31. ESTABLISHMENT ORGANISATION AND PILOT OPERATION OF THE HTSO Power Exchange Code User Guide Draft 8 October 2000 ESB INTERNATIONAL eLok MM eee AAKG V4 TABLE OF CONTENTS INTRODUCTION THE NEW INDUSTRY STRUCTURE FRAMEWORK OF CODES AND AGREEMENTS SUMMARY OF SYSTEM TRADING ARRANGEMENTS SUMMARY DESCRIPTION OF POWER EXCHANGE CODE FREQUENTLY ASKED QUESTIONS 6 10 11 12 15 am nera et WHAT DOES NET SETTLEMENT MEAN HOW DO BILATERAL CONTRACTS WORK HOW DOES HTSO ENSURE ADEQUATE INSTALLED CAPACITY HOW DOES HTSO ENSURE ADEQUATE AVAILABLE CAPACITY HOW ARE SMPS DETERMINED HOW DO CONSTRAINED ON OFF PAYMENTS WORK HOW ARE SETTLEMENT QUANTITIES DETERMINED HOW ARE ANCILLARY SERVICES HANDLED HOW ARE IMPORTS EXPORTS HANDLED WHAT CHARGES AND PAYMENTS ARE SETTLED UNDER THE POWER EXCHANGE CODE 13 25 28 29 33 34 36 38 41 62 Ref Nick Elms 3 9 Oct 00 F AnneM msoffice winword NERA 2000 PEC UserGuide Draft_dc091000 doc DK ESB INTERNATIONAL Introduction 1 INTRODUCTION This document is a deliverable of Task 4 for the Project for the Establishment of the H ellenic Transmission System Operator It contains two parts The first part is a description of the newly restructured electricity industry in Greece and contains A summary description of the new industry structure A summary of the framework of Codes and agreements
32. On Quantity of Step 3 is zero PEC B66 2 SMP Minimum Dispatch Capability Meter Quantity MNDC MQ Paragraph 66 3 specifies the formula for determining how much of the second step of a Unit s Offer price function is constrained on 66 3 The constrained on capability of the second step of the Offer Price Function of a Unit in a Dispatch Hour shall be calculated in accordance with the following equations If OP gt SMP Jand M gt then CONC Min Max MQ MNDC CONC 3 0 Max MQ CONC 0 otherwise CONC 0 where is the minimum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC B65 In the following illustration about 80 of the Offered capacity of step 2 of the Offer price function is constrained on because the SMP is less than the Offered price of the second step and the M eter Quantity is greater than the Offered capacity of the first step B cM os 2 7 ESB INTERNATIONAL How do Constrained On Off payments Work Figure 1110 Offer Price Function of a Unit DRS MWh Step 2 has a Constrained On Quantity I PEC B66 3 I I I OMP Step 3 MW f Minimum Dispatch Capability Meter Quantity MNDC MQ Paragraph 66 4 specifies the formula for determining how much of the first step of a Unit s Offer price func
33. TSO is able to arrange for available capacity well before the day before the Dispatch Day The procedures to be followed by the HTSO with regard to day ahead scheduling and the use of Ancillary Services contracts are specified the Operating Code and the Ancillary Services contracts themselves not the Power Exchange Code Paragraph 21 of Schedule B of the Power Exchange Code states 36 ESB INTERNATIONAL 5 nera sess How Does HTSO Ensure A dequate Available Capacity 21 Scheduling Procedure The procedure to be followed by HTSO in the scheduling of Units including the scheduling of Special Units Indigenous Fuelled Units Interconnectors and Ancillary Services providers and in the production of Generation Schedules shall be in accordance with the Operating Code the applicable Interconnection Agreements the applicable Ancillary Services agreements and any other applicable requirements In addition the HTSO may utilise other longer term provisions such as the provisions for generator outage co ordination scheduling provided for in the Operating Code in order to assist the organisation of adequate available capacity over the longer term 92 Participant Incentives Perhaps the most important mechanism in the STA to ensure adequate available capacity is the manner in which the SMP is determined The SMP is high when there is a shortage of capacity and is low when thereis a surplus In th
34. apacity Production Cost MW DRS MWh MW DRS MWh Unit A1 200 6 000 Load in Hour 1 MW 250 Unit B1 200 5 000 Load in Hour 1 MW Unit A2 200 10 000 Load in Hour 2 MW 350 Unit B2 200 12 000 Load in Hour 2 MW 29 ESB INTERNATIONAL nera 3595 Ga Ora were Nus What Does Ne Settlement M ean A Supplier must own adequate generating capacity to cover its load It must also provide long term confirmation as to necessary reserve capacity and availability of necessary transmission resources In this example both Suppliers own more than enough generating capacity for both energy and reserve purposes and transmission is ignored for simplicity 6 L1 Offers and Dispatch All energy is sold by Generators bought by Purchasers and settled by the HTSO TheHTSO conducts a least cost Dispatch of the full available capacity of each Unit so as to meet total load The Offers received by the HTSO in this example aretherefore as follows Figure 6 2 Example ffers Offer Price DRS MWh UnitID MW The total load is 500 MW in hour 1 and 700 MW in hour 2 The merit order and the production in each hour are thus Figure Example Merit Order and Dispatch Offer Price Output Output SMP Hr1 SMP Hr2 DRS MWh Hour 1 Hour 2 DRS MWh DRS MWh 10 000 12 000 UnitID MW Total 800 The SMP in each hour is set by the marginal Offer cost of supplying an additional MW to the system The SMP in
35. atch Instruction it may face penalties These penalties are determined on the Calculation Day Finally on the Calculation Day the HTSO determines the final amounts to bill or credit each Participant for energy bought and sold for the Dispatch Day 43 5 Timeline Billing Fifteen days after the last Dispatch Day of the month is the Billing Day the day on which any remaining settlement amounts are calculated and the total bills or credits of each Participant for the month are aggregated and sent out Funds due must be transferred on or before the day fifteen days after the Billing Day Figure 4 6 Billing and Settlement Cycle Dispatch Day One for every day of the month Calculation D ay Billing Da One for every nm i Dispatch D ay every month M y y 9 9 7 a 8 e ESB INTERNATIONAL 3505 epa AAKE 2 Summary of System Trading Arrangements 4 4 Other HTSO Responsibilities As part of its job as system operator and market operator and in addition to the tasks summarised above the HTSO assists the RAE to ensure there is adequate generation capacity and monitors Participants compliance with the terms of their Authorisations procures Ancillary Services fulfils its obligations with respect to hydro generation and follows standards regarding information disclosure and metering In addition it administers the calculation billing and settlement of transmission charges
36. bea three party agreement 1 the HTSO 2 the transmission owner 3 the connected party Coverage Construction maintenance modifications and fees 9 ESB INTERNATIONAL Framework of Codes and Agreements An important feature of the proposed document is that it is drafted as a tri partite document and this has been done to ensure that the three parties involved are tied adequately together It is believed that this addresses the issues more effectively than would be the case with two separate contracts between the pairs of parties 3 2 3 Transmission Use of System Agreement Use of the system will be essential to those acting as suppliers and to generators and it is proposed that a use of system agreement on similar terms will be provided to all these users of the system The key elements of this document are summarised in Table 3 3 Table 3 3 Summary of the Transmission U se of System Agreement Type of Document Commercial Agreement at regulated terms Objective To regulatethe terms and charges for use of the system The Parties 1 the HTSO 2 the Users either a generator or a supplier Coverage Standard terms including fees as determined by the regulatory authorities It is proposed that in order to ensure consistency in terms all users will sign up to a common agreement and that new users will join the arrangement by signing an accession agreement Fees for use of the sy
37. ch Dispatch Hour is set as being equal to the Offer price of the marginal Unit dispatched to meet demand in the ex post schedule given the level of output for which the Unit is dispatched and adjusted for the marginal rate of transmission system losses between the Unit and the Reference Node The marginal Unit is that Unit which would increase output if total demand at the Reference N ode increased by a marginal amount Inflexible Units cannot therefore set the SMP if they are constrained by their inflexibility such as a must run condition in a given hour 10 2 Administered Prices The normal method of Dispatch and or the calculation of SMPs can be suspended and thus the STA can be suspended when there is System Emergency Condition which can include certain force majeure conditions such as war or earthquakes or when there important failures that do not allow the HTSO to get the information it needs to Dispatch the system according to the Codes 39 ESB INTERNATIONAL nera How Are SMPs Determined In the event of STA suspension the HTSO will set Administered Prices The Administered Prices will be determined in relation to the prices either the forecast SMP or the actual SMP depending on which type of price is relevant in the time period s immediately preceding and or following the suspension and or by the use of estimated data In the event of a System Emergen
38. constrained off capability of the second step of the Offer Price Function of a Unit in a Dispatch Hour shall be calculated in accordance with the following equation COFC MaxUMC MQ COFC 0 In the following illustration about 2096 of the Offered capacity of step 2 of the Offer price function is constrained off because the M eter Quantity is less than the in merit capability of the first and second steps Figure 16 Offer Price Function of a Unit DR h RN Step 2 has a Constrained Off Quantity SMP EsRESESESEREEREREESARREERERSERSEREREERERERSERERRERSNERERREREERSEREHESEERERSSRHEREERRERSREHESERERERRESERHERERRRRRE PEC B63 3 MW f Meter Quantity MQ Paragraph 63 4 specifies the formula for determining the constrained off capability of the third step 63 4 Theconstrained off capability of the third step of the Offer Price Function of a Unit in a Dispatch H our shall be calculated in accordance with the following equation COFC Max IMC IMC 4 MQ COFC COFC 0 In the following illustration about three quarters of the Offered capacity of step 3 of the Offer price function is constrained off because the M eter Quantity is less than the in merit capability of each of the steps less the constrained off capability of step 2 I we I ESB INTERNATIONAL y How do Constrained On Off payments Work Figure 17 Offer Price Function
39. contact details These details are used whenever any notice or communication is given from one Person to another Person in relation to matters concerning the Power Exchange Code Schedule D sets out the amount and means by which a Person shall provide security for its financial obligations under the Power Exchange Code The security can either take the form of a letter of credit or a cash deposit and the amount secured is determined by HTSO on the basis of its estimate of a Person s net value of charges owed by that person to HTSO in respect of the Power Exchange Code over the next 2 calendar months 27 ESB INTERNATIONAL nera sees f Naa Frequently Asked Questions FREQUENTLY ASKED QUESTIONS 28 E I ESB INTERNATIONAL What Does N et Settlement M ean 6 WHAT DOES NET SETTLEMENT MEAN An important feature of the STA is that it has gross settlement in respect of contracts and net settlement in respect of ownership In section was described as meaning All electricity generated or consumed is sold by Generators bought by Purchasers and settled by the HTSO The HTSO does not take into account independent contractual arrangements between Participants with regard to its settlement of transactions in the STA HTSO does however consolidate invoices and remittances of Participants owned by the same parent entity Suppliers which are both Purchasers an
40. cost and utilising those sources available as declared by Generators with which it has prearranged Ancillary Services contracts After the HTSO has calculated the forecast unconstrained schedule and before 16 00 the HTSO determines forecast SM Ps based on the results of that schedule At 16 00 the HTSO produces list that details the forecast constrained schedule and forecast SM Ps for each Dispatch Hour of the following day Generators are sent a subset of the list showing the schedule for their Units only The HTSO also sends Purchasers a list showing how much energy their customers are forecast to consume and how much they are forecast to be charged in each hour Schedules for the use of the interconnectors with foreign countries are produced at this time and the forecast SMP for each hour is published and made availableto the public Figure 4 2 D ay Ahead HTSO publishes load forecasts and determines O perating Reserve requirements D eadline for submission of O ffers into D ay Ahead Schedule Last time an invalid O ffer can be re submitted HTSO calculates the schedules for the following Dispatch D ay HTSO calculates the forecast SMPs HTSO publishes forecast SMPs and sends out constrained schedules to Participants v v Y 11 00 12 00 13 00 16 00 0 00 24 00 19 ESB INTERNATIONAL Summary of System Trading Arrangements 4 3 2 Timeline Dispatch D ay The HTSO may instruct availabl
41. culation Day a ESB INTERNATIONAL nera sese e 57 Section XI How Are Settlement Quantities Determined Paragraph 55 of Schedule B of the Power Exchange Code specifies that the transaction each Calculation Day for each Generator records the product of its hourly Settlement Quantity and the corresponding SMP summed over the Dispatch Day The Settlement Quantity is calculated as the sum over all Units owned by the Generator of Meter Quantities i e Units in Greece adjusted for transmission losses plus the sum of the Day Ahead Quantities i e Units outside Greece also adjusted for transmission losses Figure 22 Metering Data Settlement Quality Metering Data Day Ahead Transmission Loss Quantities Factors Settlement Quantities Meter Quantities 55 Energy Payments HTSO shall calculate for each Dispatch Day in respect of each Participant Generator a daily Energy Payment in accordance with the following equation 24 50 SMP 1 1 where the Settlement Quantity for a Participant Generator g in Dispatch Hour t is calculated in accordance with the following equation 50 gt X MO 1 TLFG J Y DAQ 1 TLFG ueg i where ueg signifies that the summation is made for each Unit u that according to its Registered Information is owned or in the case of the Special Participant represented by Participant G enerator g ESB INTERNATIONAL nera ses
42. cy Condition in which involuntary load shedding occurs on a widespread basis the Administered Price will be set equal to the VOLL the Value of Lost Load Under no circumstance will an Administered Price be set higher than the VOLL 10 3 Forecast SM Ps Forecast SMPs are calculated in the day ahead scheduling process Forecast SMPs are calculated using the same methodologies and principles as specified above and are calculated using the same software as ex post SMPs Forecast SMPs are of course determined with forecast data values for Load generation availability and other factors Paragraph 20 of Schedule B specifies the rules for calculating and using forecast SM Ps The schedule used for calculating forecast SMPs is like the schedule for ex post SMPs an unconstrained one This means that it does not take into account transmission constraints In principle this is the only difference between the unconstrained schedule and the constrained schedule referred to above in section 9 of this document and referred to as the Generation Schedule in the Operating Code In practice there may be other minor differences in the way the schedules are calculated ESB INTERNATIONAL nera sees e Ta 2 How do Constrained On Off payments Work 11 HOW DO CONSTRAINED ON OFF PAYMENTS WORK Having made Offers day ahead Units that are in Greece and are scheduled day ahead in the constrained schedule are committe
43. d Generators are therefore invoiced or paid for their net financial imbalance Each Supplier is treated as a separate Generator and Purchaser in the STA in this way it is possible for the HTSO to conduct a least cost Dispatch of the full available capacity of Suppliers and not just the capacity net of their final customer load The purpose of this section is to illustrate these principles in more detail Specifically it illustrates how a Supplier being both Purchaser and a Generator can use the STA serve its load and match imbalances between its generation and consumption It also illustrates how Participants can enter into bilateral energy contracts with one another within the framework of the STA to buy and sell imbalance energy at predetermined prices rather than at SMPs if they so wish 6 1 Transactions by a Supplier For purposes of illustration it is assumed that a simplified situation consists of two Suppliers A amp B Each Supplier is reoresented by a Generator and a Purchaser Generators A amp B and Purchasers A amp B The characteristics of these Participants are shown below For simplicity a Dispatch Day is represented by two Dispatch Hours and the illustrations show the Dispatch and settlement conducted by the HTSO for this simplified Dispatch Day 61 Example Situation Supplier A Generator A Purchaser A Comprising Supplier B Generator B Purchaser B Comprising Capacity Production Cost C
44. d to or taken from Greece s interconnected transmission system is bought and sold through the STA Only Participants are entitled to buy and sell electricity in the STA A Participant is an entity that has signed a Participation A greement 1 nsomerestructured markets this arrangement is known as a single settlement system in which the market is spot market 2 At least initially the HTSO will not make any unregulated profits from the outcomes of the services it provides ie it will not be subject to performance based regulation like some other ISOs Power Exchanges are This affects the trading arrangements because it means that each of the ways in which the HTSO fulfils its functions is specified in the Codes and is not at the discretion of the HTSO For example the HTSO must schedule and dispatch the system in a way that is both security constrained and least cost 3 Electricity sold by Distribution Embedded Units will also tradethrough the STA 14 ESB INTERNATIONAL nera sess T LOS Summary of System Trading Arrangements thereby agreeing to be bound by the Power Exchange Codeas a condition for obtaining from the Minister of Development one or more of the following an Electricity Supply Authorisation and or an Electricity Generation Authorisation There aretwo principal categories of Participants Purchasers and Generators 4 1 1 Purchasers The category Purchasers comprised
45. d to providing their offered capacity in accordance with their offered price and quantity parameter submissions and within the limits of their technical parameters specified in their Registered Information if called upon by the HTSO to run in the Dispatch Day In return the HTSO guarantees that flexible Units in Greece at least recover all their costs as reoresented by their Offers over the course of the Dispatch Day In general during any hour in which a Unit is dispatched the SMP shall at least equal its Offer Price Accordingly all available Units whose Offer price is below the SMP shall be fully dispatched to run and no available Units whose Offer price is above the SMP shall be dispatched to run However there might be occasions when the Dispatch is not consistent with the SMP meaning that given the SMP a Generator might be better off producing a different amount than it was instructed to produce by the HTSO This situation is not typical but can arise because of transmission constraints or other reasons In these situations additional Constrained On Payments and Constrained Off Payments are made to Generators These payments are evaluated on an hourly and daily basis The exception to this rule is that no additional payments are made in respect of Units whose Registered Information or Offer is changed during the course of a Dispatch Day Units who fail to comply with Dispatch Instructions or for whom metering data has not been suppl
46. dance with the methods specified in the Operating Code and Ancillary Services Agreements Generators not selected in the Generation Schedule are able to re dedare their availability downwards for the following Dispatch Day This means HTSO must schedule sufficient generators day ahead to cover for the possibility of unforced generation outages and errors in its load forecast Even if these generators are not called upon to run they may be entitled receive a payment for being available in accordance with an Ancillary Service A greement On an on going basis right up until the Dispatch Hour HTSO may subsequently modify the day ahead schedule HTSO may notify a generator with which it has an arrangement to provide Ancillary Services that it is required to synchronise or standby in order to provide one or more types of Ancillary Service In addition to payments made through Ancillary Services Agreements generators may also be entitled to Constrained On and or Constrained Off payments if they are dispatched out of merit in order to provide an Ancillary Service These payments are described in section ESB INTERNATIONAL 2505 2 How Arelmports Exports Handled 14 HOW AREIMPORTS EXPORTS HANDLED The Power Exchange Code makes provision for the commercial aspects of trading energy and ancillary services across Greece s interconnectors with other countries The treatment of interconnectors is designed to accommo
47. date PPC s existing interconnector agreements with other system operators in Bulgaria FYROM and Albania whilst allowing Participants that meet certain requirements to also trade internationally 14 1 Exporting Purchasers Exporting Purchasers are Participants that purchase energy through the PEC for the purpose of export from Greece to supply customers in another country An Exporting Purchaser must hold a generation authorisation and meet the appropriate technical requirements to export energy from Greece In particular an Exporting Purchaser must hold the rights to use interconnector capacity out of Greece before the HTSO will schedule an export transaction The methods by which Exporting Purchasers may obtain rights to use interconnector capacity out of Greece are outside of the STA is limited the amount of energy it can export given hour by amount of capacity specified in its generation authorisation less the aggregate of the HTSO registered maximum loads for the customers in Greece for which the Exporting Purchaser has responsibility in the case of entities that are also holding a supply authorisation must make the appropriate arrangements with SOs adjoining countries for the receipt of the energy and must meet other appropriate technical requirements specified by the HTSO Where an Exporting Purchaser wishes to export energy from Greece it must nominate the amount of its exports by 12
48. e Units in Greece to start up and synchronise at some point during or before the Dispatch Day to ensure adequate generation capacity is available for the real time Dispatch of the system Generators are obliged to follow these instructions In real time system load generation availability and other constraints may change from those forecast day ahead Although these changes are normally not significant they must be accounted for so that the transmission system is operated reliably Accordingly a separate Dispatch in each Dispatch H our determines the actual energy quantities dispatched from Units in Greece to meet actual demand on the system The Dispatch is determined according to the merit order established day ahead from the prices in the Offers The Units have to obey their Dispatch Instructions in real time so as to keep the transmission system stable Scheduled Generators are not able to resubmit the quantity component of their Offers between the time the Offer was submitted and the Dispatch Hour unless they have a legitimate reason to do so A legitimate reason is a prior approval by the HTSO or an unexpected forced outage that renders some or all of the capacity of the Unit unusable or hazardous to use for reasons of safety or protection of physical equipment The HTSO may only issue prior approvals for reasons relating to unpredictable external factors such as wind strength in the case of wind powered Units Offer revisions that are
49. eece although it covers much of the same material Like that document this manual does not have legal status its purpose is solely to act as a guide to the new industry structure The Codes together with the Authorisations ESB INTERNATIONAL nera sess Introduction issued by the Minister of Development to entities involved in the generation and supply of electricity and other associated agreements constitute the legally binding requirements rights and obligations for participation and operation of the STA and the operation and control of the transmission system e 1 ESB INTERNATIONAL nera sese AAKE The N ew Industry Structure 2 THENEW INDUSTRY STRUCTURE 2 1 Overview The Electricity Law has introduced a new structure for the electricity industry in Greece where there is a degree of competition in generation and supply This structure which applies only to the inter connected system has been introduced in order to comply with the EU Electricity Directive and the extent of the competitive sector will need to increase to meet the requirements of the Directive Central to these changes is the creation of the HTSO an independent system operation organisation The HTSO will take over from PPC the responsibility for system planning and operation induding despatch of generators and will also take responsibility for the operation of the new trading arrangements
50. ems in accordance with the Power Exchange Code and PPC GBU would schedule exports to foreign system in accordance with the Power Exchange Code Thus the net costs or benefits of the scheduled transfers would be retained by the PPC Group nera Sess What Charges and Payments are Settled Under the Power Exchange Code 15 WHAT CHARGES AND PAYMENTS ARE SETTLED UNDER THE POWER EXCHANGE CODE Paragraph 28 of Schedule B of the Power Exchange Code specifies that energy Uplift and transmission payments and charges are settled under the Power Exchange Code 28 HTSO Responsibilities HTSO s responsibilities with respect to settlement are to determine SMPs and Settlement Quantities and in turn determine payment amounts to Participants providing Energy and determine charge amounts to Participants utilising Energy 2 calculate and settle payments and charges in respect of Ancillary Services and other U plift costs and 3 calculate and settle payments and charges in respect of transmission use of system charges and transmission connection charges Numerous debit and credit transactions involving the H TSO s settlement accounts constitute the process of settlement These transactions for energy Uplift and transmission payments and charges are set out throughout Schedule B 15 1 Energy Much of Schedule B is devoted to the determination of Energy Charges and Energy Payments and the means b
51. ergy flows across the interconnectors differ from those scheduled in the constrained forecast generation schedule and the price or effective price for settling imbalances interconnector flows the HTSO s agreements with neighbouring control area operators differs from the SMP inthe STA 65 ESB INTERNATIONAL nera 2688 Naa How Arelmports Exports Handled The net cost of interconnector trade is accumulated to the Uplift account as it is incurred in accordance with Paragraph 78 78 Determination of Hourly Net Energy Cost of Interconnection Flow Deviations On the Calculation D ay in respect of aDispatch Day HTSO shall determine the net Energy cost of Interconnector flow deviations in respect of each Dispatch Hour in that Dispatch D ay as being equal to the sum over all Interconnectors of 1 net scheduled inflows of Energy over Interconnector pursuant to PEC Reference source not found excluding any amounts scheduled by HTSO with an External System Operator to offset or pay back previous Interconnector schedule deviations minus 2 actual net inflows of Energy all multiplied by 3 the SMP in respect of the Dispatch Hour and 4 adjusted as HTSO determines appropriate by a relevant Transmission Loss Factor in respect of the Interconnector 14 7 Treatment of Existing Interconnector A greements The existing Interconnector agreements place all rights and respon
52. erve The methods by which the RAE forms its opinions on the authorisation of individual candidate Suppliers are outside of the STA However the Codes of the System Trading Arrangements assume that in order for a Supplier to be recommended by the RAE and subsequently to be authorised to serve load totalling X MW the RAE has satisfied itself that in addition to other obligations the Supplier owns Units with operational net capacity of at least X MW the Supplier also owns has contracted a firm basis further operational net capacity of aX MW where a is a percentage installed reserve requirement specified by the HTSO and approved by the RAE and is the same value for all Suppliers regardless of ownership all of the capacity in question is located in accordance with the Greek Electricity Law and all necessary confirmation as to the availability of transmission capacity has been provided including the ownership by the Supplier of rights to use interconnector capacity into Greece for the amount of the operational net capacity which is located outside of Greece and the HTSO has conducted or monitored operational tests or other tests on the Units involved to confirm that the 1 a X MW of net capacity is operable and meets the technical requirements for participation in the STA It is the responsibility of the RAE to keep the HTSO informed of the terms of each approved Electricity Supply Authorisation including any chan
53. ges over time and of the obligations imposed under each BLOK T Feet 34 ESB INTERNATIONAL How Does HTSO Ensure Adequate Installed Capacity 8 2 Compliance with Electricity Supply Authorisations The Codes specify that once a Supplier is authorised it must inform the HTSO and the RAE of any subsequent change in the operational capability or ownership of its net capacity The Codes also specify that the HTSO will conduct on going studies and operational tests over time to confirm that Suppliers continue to provide the level of operational net capacity that complies with their Electricity Supply Authorisations The methods by which Suppliers may obtain rights to use interconnector capacity into Greece are outside of the STA However the Codes require that the HTSO confirm on an on going basis that Suppliers hold the necessary rights in respect of Units in foreign countries before an Offer from such a Unit is accepted in the STA The Codes also require that one or more Suppliers take responsibility for the total load of each customer On an on going basis it is a responsibility of the HTSO to confirm that the metered aggregate MW load of the Supplier s customers complies with its Electricity Supply Authorisation in any hour It is also the responsibility of the HTSO to record the details of the Suppliers other obligations under their A uthorisations including their Electricity Generation A uthorisations where
54. hour 1is therefore DRS 10 000 MWh Unit A2 is the marginal Unit The SMP in hour 2 is DRS 12 000 MWh Unit B2 is marginal 30 ESB INTERNATIONAL What Does N et Settlement M ean The transactions of each Participant are as follows Generator A sells 300 MW in hour 1 for DRS 3 000 000 and 400 MW in hour 2 for DRS 4 800 000 Generator sells 200 MW in hour 1 for DRS 2 000 000 and 300 MW in hour 2 for DRS 3 600 000 Purchasers A and B each buy 250 MW in hour 1 for DRS 2 500 000 and 350 MW in hour 2 for 4 200 000 Figure 6 4 Example Transactions ans Temors DRS DRS Total DRS MM 000s Price 000s 000s Gen A Sells 12 000 7 800 Gen B Sells 12 000 5 600 Total Sales Purch A Buys 12 000 Purch B Buys 12 000 Total Purchases The HTSO consolidates invoices and remittances of Participants owned by the same parent entity and Suppliers are consequently invoiced or paid for their net imbalance Supplier A is therefore paid DRS 1 100 000 by the HTSO and Supplier B is charged DRS 1 100 000 Figure 6 5 Example Settlement Supplier A Total DRS Supplier B Total DRS Generator A Sales 7 800 Generator B Sales less Purchaser A Purchases less Purchaser B Purchases Net Remittance Supplier A 1 100 Net Remittance Supplier B 1 100 The practical effect of the net invoice or payment is that Supplier A and Supplier B are paid or charged according to their net generation or consumption in each hour 31
55. hronise for the Dispatch Day then it is given an additional constrained on payment so that all its costs are recovered This means that a Unit which is instructed to start and that does not fall into one of the categories of exceptions above is guaranteed to at least recover its costs over the day even it was inflexible during some hours 113 Illustration The remainder of this section illustrates in more detail with diagrams and with reference to the rules in the Power Exchange Code how the Constrained On Payments and Constrained Off Payments are calculated 8 exception to this rule is in the case of a Unit being constrained on by the HTSO because it is an Indigenous Fuelled Unit 42 ESB INTERNATIONAL nera sess How do Constrained On Off payments Work Constrained On Payments and Constrained Off Payments are calculated pursuant to section XIV of Schedule B of the Power Exchange Code Paragraph 60 of Schedule B specifies that the payments are calculated hourly 60 Timing of Calculation of Constrained On and Off Payments On the Calculation Day in respect of a Dispatch Day HTSO shall calculate Constrained On Payments and Constrained Off Payments in respect of each Unit in Greece for each Dispatch Hour of the Dispatch Day The rules for the calculation of Constrained On Payments and Constrained Off Payments rely on the 3 step form of the Offer function illustrated in the followi
56. ied Units in foreign countries and Special Units and no additional payments are made in respect of the Special Participant 11 1 Constrained O ff Payments When the instructed output of a Unit in Greece in a Dispatch Hour is below that consistent with the SMP for that hour it is paid a Constrained Off Payment This payment equals the difference between the SMP and the Unit s Offer price multiplied by the MW difference between its instructed output and the output level that would be consistent with the SMP However since the Offer price may vary over the range of offered capacity of a Unit this description is somewhat of a simplification Section 11 illustrates the exact rules in the Power Exchange Code The output level that is consistent with the SMP in the case of constrained off Units is the maximum actual availability of the Unit in the Dispatch Hour concerned Generally this is the maximum offered capacity of the Unit However if a Unit is held tightly against its maximum ramp up rate or otherwise not able to increase output beyond that instructed ESB INTERNATIONAL 5 nera sess How do Constrained On Off payments Work during a Dispatch Hour because of an operating constraint it has specified then the actual output level is consistent with the SMP and the Unit does not receive a Constrained Off payment in that hour Paragraph 61 of Schedule B of the Power Exchange Code defines the exact rules for h
57. is way the SMP encourages Participants to have incentives consistent with the HTSO s responsibilities if the SMP is high Generators will have incentives to make their Units available because they can profitably sell their output and Suppliers Eligible Customers will have incentives to reduce Load if at all possible In the event of a System Emergency Condition or risk of aa System Emergency Condition these incentives may be very strong because the SMP can be set to a very high level From paragraph 51 of Schedule B 51 Administered Prices in System Emergency Conditions 16 In the event of a System Emergency Condition in which involuntary Load shedding occurs on a widespread basis and thereis no Capacity Adequacy HTSO shall set the SM P equal to an Administered Price that equals the Value of Lost Load 2 HTSO shall set the Value of Lost Load at a level approved by the Minister of Development HTSO shall publish the Value of Lost Load on the HTSO Web Site and notify Participants of any change to the Value of Lost Load Conversely if the SMP is low Generators will take this as a signal as being a good time to schedule an outage of their Units if repairs or other circumstances dictate Low prices area signal to Suppliers and Eligible Customers of surplus capacity and thus are a signal to them that it is a good time to increase consumption if they are at all flexible 37 ESB INTERNATIONAL sees 22
58. istence of a CFD does not change the way the Generator offers its capacity to the HTSO or the way in which the HTSO operates the system Furthermore the settlement of CFD payments is made independently of the HTSO between the Participants concerned Consequently since executing bilateral transactions in the form of CFDs does not require any special action from the HTSO in addition to its regular responsibilities as system operator and market operator there are no special rules regarding these contracts in the STA TheHTSO does not need to be aware of their existence ESB INTERNATIONAL nera sees 5 ALKE e E How Does HTSO Ensure A dequate Installed Capacity 8 HOW DOES HTSO ENSURE ADEQUATE INSTALLED CAPACITY An important element in any liberalised electricity market is the means of ensuring that there is sufficient installed capacity to meet demands In Greece the Greek Electricity Law imposes certain obligations on Suppliers which are designed to ensure the adequacy of installed capacity 8 1 Issuance of Electricity Supply Authorisations Electricity Supply Authorisations are issued by the Minister of Development following an opinion from the Energy Regulatory Authority RAE The Greek Electricity Law specifies that one condition of obtaining an Electricity Supply Authorisation is that the candidate Supplier owns adequate generating capacity and has satisfactory long term arrangements in place for the necessary level of res
59. lated by the HTSO and advised to Participants This process also determines the merit order for the real time Dispatch The second step is the real time Dispatch of Generators by the HTSO to meet real time load on the system This occurs throughout every Dispatch Hour on the Dispatch Day and determines the actual quantities of energy traded Metering quantities are then verified and finalised Afterwards the SMPs at which the energy quantities in the Dispatch are traded are determined using actual Unit availability and actual system load Since this occurs after the Dispatch prices are known as ex post The fourth step occurs after the SMPs are calculated This step consists of provisions for making payments to Generators in the legitimate but infrequent instances in which the Dispatch quantities and SMPs might not be consistent To not be consistent means in principle a circumstance in which a Generator would be better off to produce a different amount than that it was instructed to produce by the HTSO given the SMP The fifth step involves verification and finalisation of settlement amounts determination of penalties and other charges if any and a monthly cyde of settl ement and billing activities Thefollowing is a summary timeline of thefive steps of the System Trading A rrangements nera sees AAKE ESB INTERNATIONAL e Summary of System Trading Arrangements Figure 4 1 Summary of Timelines
60. ments have been made for the receipt of energy from the Exporting Purchasers concerned and or the delivery of energy by the Generators with foreign Units concerned and confirmation has been received from the adjoining system operators regarding the net ie aggregated scheduled quantity on the interconnectors in each relevant time period and the terms with which any imbalances from that schedule are managed Where for one of these reasons the HTSO cannot schedule an Offer from a foreign Unit that was accepted in the constrained forecast generation schedule or cannot accept a valid export nomination the HTSO modifies the constrained forecast generation schedule In doing so it adheres to the principle of maximising the economic value of the transactions that can occur subject to its system security obligations If it is necessary to curtail Offers from foreign Units or to curtail valid export nominations the HTSO does so in accordance with the terms with which the rights to use interconnector capacity were granted 14 4 Dispatch Exporting Purchasers and Units in foreign countries incorporated into the scheduled interconnector flow cannot update their schedules once the constrained forecast generation schedule has been made for the Dispatch Day Accordingly Offers in respect of Units in foreign countries are not taken into account in the real time Dispatch The net amount scheduled on individual interconnectors may however be adjusted
61. ms Section XV of Schedule B paragraphs 71 to 73 specifies the rules for Ancillary Services The costs incurred by the HTSO through Ancillary Service agreements it enters into are recovered through the Uplift sub account for Ancillary Services Costs relating to Ancillary Services providers that may be due Constrained On Payments or Constrained Off Payments are accounted for in the Uplift Sub account for Constrained On Payments or Constrained Off Payment not the Uplift sub account for Ancillary Services The treatment of Ancillary Services is also described in section this document Paragraph 74 of Schedule B specifies the treatment of HTSO administration charges The HTSO will be regulated by RAE as to the administration costs it can recover and it will not necessarily be able to pass through all costs at the same time as it incurs them Paragraphs 78 and 79 of Schedule B specifies the treatment of Interconnector net costs Interconnector net costs are the costs of managing thelnterconnectors They include e Direct costs incurred by the HTSO paragraph 79 2 and 69 ESB INTERNATIONAL nera seve E e Tia AAKE 2 What Charges and Payments are Settled Under the Power Exchange Code the cost relative to SMP of unscheduled flows and subsequent scheduled flows to offset or pay back previous unscheduled flows These costs paragraph 78 are not direct costs to HTSO as is described below under losses adjustments
62. net effect on total Uplift costs Paragraph 81 of Schedule B specifies other charges that the HTSO can recover through Uplift These consist of charges so as to deal with rounding errors charges related to interest and credit facilities that the HTSO is not authorised to otherwise allocate directly to Participants charges relating to payment default in certain situations and residual costs attributable to the Special Participant Penalties which may be assessed by the HTSO according to paragraphs 18 or 102 of Schedule B or as otherwise provided in the Power Exchange Code or Operating Code are not settled under the Power Exchange Code Paragraph 103 specifies that HTSO informs RAE of the assessed amounts and settlement if any is not an HTSO responsibility Paragraph 85 specifies the way in which Uplift Charges are transacted through the HTSO settlement accounts so as to be assigned to Participants ESB INTERNATIONAL nera sees 5 ALKE e What Charges and Payments are Settled Under the Power Exchange Code 85 Account Transactions for U plift Charges Immediately subsequent to determining U plift charges pursuant to PEC B84 HTSO shall 1 credit each of the Uplift sub accounts specified in PEC B29 2 which had a debit balance as of the end of the Calculation D ay in respect of the last calendar day in the month by an amount equal to that debit balance 2 debit each of the Uplift sub accounts specified in PEC B2
63. ng diagram Figure 1 1 Offer Price Function of a Unit DRS MWh Step 2 MW Minimum Dispatch Capability Maximum Dispatch Capability MNDC MXDC Paragraphs 61 and 65 of Schedule B specify how the minimum dispatch capability and maximum dispatch capability of a Unit in a Dispatch Hour illustrated in this diagram are calculated In order to calculate Constrained Off Payments for a Unit it is necessary to first calculate the in merit capability of each step of the Unit s Offer price function in a Dispatch Hour Paragraph 62 of Schedule B sets out how this is done Paragraph 62 2 specifies the formula for determining how much of the first step of a Unit s Offer pricefunction is in merit ESB INTERNATIONAL How do Constrained On Off payments Work 622 in merit capability of the first step of the Offer Price Function of a Unit in Dispatch Hour shall be calculated in accordance with the following equations lt SMP then IMC Min O MXDC otherwise IMC 0 wheret is a Dispatch H our that falls within D ispatch D ay d and where M XD Cu is the maximum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC B61 In the following illustration all of the Offered capacity of step 1 of the Offer price function is in merit because the Offered price of thefirst step is less than SMP Figure L1 2 Offer Price Function of a Unit DRS MWh
64. ning how much of the third step of a Unit s Offer price function is in merit 45 How do Constrained On Off payments Work 624 Thein merit capability of the third step of the Offer Price Function of a Unit Dispatch Hour shall be calculated in accordance with the following equations If OP lt SMP then IMC 3 Min OQ MXDC otherwise 0 wheret is a Dispatch H our that falls within Dispatch D ay d and where M XD Cu is the maximum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC B61 In the following illustration about three quarters of the Offered capacity of step 3 of the Offer price function is in merit because although the Offered Price of step 3 is less than SMP some of the Offered capacity of step 3 exceeds the maximum dispatch capability of the Unit in the Dispatch Hour Figure 14 Offer Price Function of a Unit DRS MWh Steps 1 amp 2 and most of Step 3 are Merit 1 SMP PEC B62 4 MW f Minimum Dispatch Capability Maximum Dispatch Capability MNDC MXDC In order to calculate Constrained Off Payments for a Unit it is necessary to also calculate the constrained off capability of each step of the Unit s Offer price function in a Dispatch Hour Paragraph 63 of Schedule B sets out how this is done Paragraph 63 2 specifies the formula for determining the constrained off capability of the fi
65. not demonstrably legitimate result in penalties Under no circumstances may the price parameters of an Offer change between the time of submission into the day ahead forecast and the actual Dispatch Hour Scheduled use of theinterconnectors is locked in from the day ahead schedule Two hours before the Dispatch H our the HTSO begins to calculate the Dispatch This time period is designed to allow the HTSO enough time to analyse Offers prior to issuing Dispatch Instructions Irrespective of this two hour period the HTSO always endeavours to use the latest availability and other system information to determine Dispatch Instructions so as to maximise system reliability and minimise the cost of Dispatch Just prior to the start of each Dispatch Hour the HTSO finalises an updated schedule of expected generation for the remainder of the Dispatch Day This scheduleis used mainly for the HTSO s own planning purposes but any updates are advised to the Generators concerned Within the Dispatch H our the HTSO calculates the real time final Dispatch ESB INTERNATIONAL nera sees AAKE e Summary of System Trading Arrangements Figure 4 3 Dispatch D ay HTSO begins determination of hourly schedule HTSO determines hourly schedule A Dispatch Hour Time horizon of hourly v 1 schedule D hour 2 hours D hour 0 00 24 00 4 3 3 Timeline Dispatch Hour In making the calculation of real time Dispatch the HTSO c
66. nted in the 3 step price function plus the Offered start up price Paragraph 68 imposes additional restrictions M I ESB INTERNATIONAL How do Constrained On Off payments Work 68 Additional Constrained On Payments 1 Except as provided PEC B69 HTSO shall make an additional Constrained On Payment to a Participant G enerator in respect of a Unit if a the sum of Energy Payments pursuant PEC B56 plus Constrained O ff Payments pursuant to PEC B64 if any plus Constrained On Payments pursuant to PEC B6 if any do not recover the offered cost of the Unit over the Dispatch D ay as evaluated by HTSO pursuant to PEC B68 2 b HTSO instructed the Unit to start up and synchronise so as to generate Energy on the Dispatch D ay and c in no Dispatch H our during the Dispatch Day was the Unconditional M ust Run Output of the Unit greater than zero 22 In making its determination of offered cost of a Unit over the Dispatch Day HTSO shall determine the cost of generating the Unit s Meter Quantity in each Dispatch Hour given the Offer Price Function and Offer Start Up Price of the Unit for that Dispatch D ay and given the synchronisation status of the Unit at the start of the Dispatch Day 5 Additional Constrained On Payments if any shall be equal to the amount as determined by HTSO by which the Participant G enerator would otherwise under recover costs pursuant to PEC B68 1a in respect of theUnit o
67. of a Unit DRS MWh Step 3 has a Constrained Off Quantity SMP PEC B63 4 MW f Meter Quantity MQ Paragraph 64 specifies the formula for determining the Constrained Off Payment for the Unit and all other U nits owned by the corresponding Generator in the Dispatch Hour 64 Determination of Constrained O ff Payments of a Unit Except as provided in PEC B69 the Constrained Off Payment in respect of a Unit in a Dispatch Hour shall be calculated in accordance with the following equation 3 Max 0 SMP 1 TLFG OP COFC ueg 5 1 uts wheret is a Dispatch Hour that falls within Dispatch D ay d where Unit u is located at Node where ueg signifies that the summation is made for each Unit u that according to its Registered Information is owned by Participant G enerator g and where HTSO in order to fairly account for the effect of Distribution Loss Factors of Distribution Embedded Units may in accordance with the terms of its authorisation appropriately adjust the equation in respect of a Distribution Embedded Unit so as to account for a Distribution Loss Factor AS nera 5 ners 3 ESB INTERNATIONAL How do Constrained On Off payments Work In the following illustration Constrained Off Payments equal to the black shaded area are made in respect of the Unit for the Dispatch Hour In this simplified illustration the effect of Transmission Lo
68. ontinues to use the merit order as determined day ahead and it utilises real time system status information including measurements of actual system load and any re declarations of Unit availability Every 5 minutes the HTSO recalculates Base Point Instructions for each Unit and notifies each Unit of their new level of instructed output The objective of the Dispatch is to minimise cost as represented by the Offers subject to system security and other constraints ie including all transmission system constraints Between the 5 minute Base Point Instructions the HTSO issues other Dispatch Instructions for example regulation instructions to Units on automatic generation control AGC and instructions to activate Operating Reserve if system conditions suddenly change and Spinning Reserve or Standing Reserve is called upon 21 ESB INTERNATIONAL Summary of System Trading Arrangements Figure 4 4 Dispatch Hour HTSO issues Base Point Instructions HTSO issues UTE ah od Instructions 0 05 0 10 0 15 0 20 0 25 0 30 0 35 040 0 45 0 50 0 55 Start of End of D Hour D Hour Sa 2 Dispatch Instructions for the Dispatch Hour 4 3 4 Timeline M etering Ex Post Price and Settlement By the end of the day following the Dispatch Day all metering data in respect of the Dispatch Day must be sent to the HTSO The day five days after the Dispatch Day is known as the Calculation Day In its role a
69. ost expensive accepted flexible Unit s in each hour so in principle no one who offered and whose Offer was accepted in this schedule is selected to run at a price below their Offer price The second of the schedules includes the effect of transmission constraints and is thus known as a constrained It is produced so as to determine forecast production of energy and Operating Reserve by each Unit for each hour of the Dispatch Day The day ahead forecasting process occurs once a day and within that day there are a number of deadlines The HTSO publishes its load forecast at 11 00 to assist Generators plan their availability It also determines its Operating Reserve requirements at this time 18 ESB INTERNATIONAL Summary of System Trading Arrangements Next all Offers from Generators and all export schedules from Exporting Purchasers must be received by the HTSO before 12 00 This deadline is designed to allow the HTSO sufficient time to advise inflexible plants well in advance of the actual Dispatch The HTSO notifies Generators by 12 30 indicating whether the data contained in their Offer was valid or invalid Generators who have submitted invalid data follow procedures for resubmission and must resubmit by 13 00 Next the HTSO calculates the forecast unconstrained and constrained schedules for the Dispatch Day In the constrained schedule the HTSO selects providers of Operating Reserve while minimising total
70. ow this maximum is determined 11 2 Constrained On Payments When the instructed output of a Unit in Greece in a Dispatch Hour is above that consistent with the SMP for that hour it is paid a Constrained On Payment This payment equals the difference between its Offer price and the SMP multiplied by its instructed MW output in that Dispatch Hour Again since the Offer price may vary over the range of offered capacity of a Unit this description is somewhat of a simplification Section illustrates the exact rules in the Power Exchange Code The output level that is consistent with the SMP in the case of constrained on Units is the minimum actual availability of the Unit in the Dispatch Hour concerned Generally this is the minimum offered capacity of the Unit Consequently a Unit constrained from producing less because of a minimum output level constraint during a Dispatch Hour does not receive a Constrained On Payment in that hour In addition a Unit constrained from producing less because of its maximum ramp down rate during a Dispatch Hour does not receive a Constrained On Payment in that hour Paragraph 65 of Schedule B of the Power Exchange Code defines the exact rules for how this minimum is determined Having evaluated all Constrained On Payments and Constrained Off Payments over the Dispatch Day if a Unit in Greece still didn t recover its costs as represented by its Offer and it was instructed by the HTSO to start up and sync
71. purpose of this Schedule HTSO shall establish one or more Import N odes in respect of each Unit located outside of Greece Such Import N ode s shall be the Node s at which Energy imported in accordance with the right of the Participant Generator owning the Unit to use the Interconnector s is scheduled to be delivered to the Transmission System 2 For the purpose of this Schedule B HTSO shall establish one or more Export N odes in respect of each Exporting Purchaser Such Export N ode s shall be the N ode s at which Energy exported in accordance with the right of the Exporting Purchaser to use the Interconnector s is scheduled to be taken from the Transmission System HTSO determines the quantity of international trade for a Participant by determining a Day Ahead Quantity for each Dispatch H our for the Participant s imports and exports accepted in the constrained forecast generation schedule in respect of each interconnector For the purposes of settlement Day Ahead Quantities are delivered to or taken from the transmission system at their associated import node or export node Section 12 descri bes how these quantities are adjusted for transmission losses and aggregated into Participants Settlement Quantities The HTSO and neighbouring system operators settle any imbalances between scheduled and actual flows across their interconnectors There may be a net cost to the HTSO for settlement of these imbalances if actual en
72. rcial agreement subject to regulation Objective To govern the relationship between the transmission owner and the HTSO so as to ensure that the HTSO is able effectively to control the operation and development of the inter connected system The Parties 1 the HTSO 2 the transmission owner PPC s TBU Coverage Operation of the system maintenance and performance standards new connections procedure for system development and fees The key elements of the agreement that has been drafted are those designed to ensure that the HTSO has the necessary degree of control and that it can ensure effective development maintenance and physical operation of the inter connected system It is important to note that the TCA does not cover any transmission assets not forming part of the inter connected system 32 2 Transmission Connection A greement These connection agreements will be required in all cases where a party is connected to the transmission system and Table 3 2 summarises the main elements of the proposed model Broadly similar terms would apply whether the connected party is a generator or aload Table 3 2 Summary of the Connection Agreement Type of Document Commercial Agreement at regulated terms Objective To ensure that the connection is properly provided maintained modified etc at terms that are effieicent and fair to the connected parties The Parties This is proposed to
73. rity RAE requires that for all Generators located in Greece regardless of ownership the Offer prices for each offered Unit must reflect the true and auditable variable and start up costs of that Unit Gross settlement in respect of contracts net settlement in respect of ownership All electricity generated or consumed is sold by Generators bought by Purchasers and settled by the HTSO The HTSO does not consider independent contractual arrangements between Participants when carrying out its settlement of STA transactions The HTSO does however consolidate invoices and remittances to Participants owned by the same parent entity Suppliers which are both Purchasers and Generators in the STA are therefore invoiced or paid for their net financial imbalance Each Supplier is treated as a separate Generator and Purchaser in the STA in this way it is possible for the HTSO to conduct a least cost Dispatch of the full available capacity of Suppliers and not just the capacity net of their final customer load Cost of service regulation of the ISO PX The HTSO is a for profit entity It makes a regulated margin on the cost of the services it provides and it passes all its costs through to Participants The remainder of this section describes the Participants of the STA and the key features of how the STA operates including how it relates to the scheduling and Dispatch of generation 41 Participants in the STA All electricity delivere
74. rst step his sae ESB INTERNATIONAL 1 dh How do Constrained On Off payments Work 632 The constrained off capability of the first step of the Offer Price Function of a Unit in a Dispatch our shall be calculated in accordance with the following equation COFC Max IMC MQ 0 ut Meter Quantities are used in this formula and in subsequent formulae as opposed to Dispatch Instruction quantities which may be regarded by some as more intuitive However if Meter Quantities vary too much from Dispatch Instruction quantities Units are subject to being denied any Constrained Off Payments or Constrained On Payments in accordance with paragraph 69 and non compliance penalty provisions provided for elsewhere in the Power Exchange Code will apply In the following illustration none of the Offered capacity of step 1 of the Offer price function is constrained off because the Meter Quantity is greater than the in merit capability of the first step Figure 15 Offer Price Function of a Unit DR h RUN Constrained Off Quantity of Step 1 is zero SMP ERRESESESEREEREREESARERERRERSERSEREREERSEESSERERRERENERHEREREERSRUHESERRERSNERHRREERRERSEEHERERERRERRESERHRRERRRRE PEC B63 2 MW t Meter Quantity MQ Paragraph 63 3 specifies the formula for determining the constrained off capability of the second step ESB INTERNATIONAL How do Constrained On Off payments Work 633
75. s market operator the HTSO never takes title to the electricity traded it acts as a financial clearing house matching sales to purchases each Calculation Day During this day the HTSO first resolves any disputes and or inconsistencies and determines the final hourly Meter Quantities of energy supplied and consumed by each Participant in each hour Figure 4 5 M etering Cycle Meter data is sent to the HTSO Calculation D ay Hourly Meter Quantities are established for v each Participant Y End of D End of D End of D End of D End of D Dispatch D ay Day 1 Day 2 Day 3 Day 4 Day 5 a ESB INTERNATIONAL nera sess Sire Summary of System Trading Arrangements Next on the Calculation Day once each Meter Quantity has been determined the HTSO calculates the SM Ps the prices at which energy trades the STA In calculating SMPs the HTSO first calculates an ex post unconstrained schedule for each Dispatch Hour The calculation of this least cost schedule is done independently for each Dispatch Hour and uses actual Unit availability actual Offer prices and metered system load from each Dispatch Hour It ignores the effect of transmission constraints in the same way the day ahead unconstrained schedule does SMPs for each hour are then set at the Offer prices of the most expensive accepted flexible Unit s in the ex post unconstrained schedule In addition if a Unit fails to comply with a Disp
76. sibilities on PPC as the party representing the Greek system Since Article 15 of the Electricity Law prevents HTSO from contracting for the sale or purchase of electricity unless required to do so for the provision of ancillary services HTSO cannot take over all responsibilities of these agreements Rather HTSO would take over lead responsibility for the execution of the agreements on the Greek side with certain functions assigned to PPC HTSO would have overall technical responsibility for the execution of the agreements but the specific commercial rights and responsibilities would be split as follows 1 HTSO would be responsible for all imports and exports scheduled within the day When HTSO schedules a short term import or export to cover an emergency or provide system support it can be regarded as making a purchase or sale under an ancillary services agreement with the foreign system operator 2 HTSO would be responsible for deviations from schedule and any subsequent scheduled energy exchange required as a result of the deviation from schedule 3 PPC would be responsible for day ahead or longer scheduled exchanges to and from the foreign system operator in effect PPC would retain the existing rights and LOK os 66 B ne ra AA 2 7 ESB INTERNATIONAL How Arelmports Exports Handled responsibilities for these scheduled energy exchanges between systems PPC DBU would schedule imports from foreign syst
77. ss Factors has been ignored Figure 11 8 Offer Price Function of a Unit DRS MWh Constrained Off Payment in this Dispatch Hour SMP a e nnna a n PEC 64 MW f Meter Quantity MQ In order to calculate Constrained On Payments for a Unit it is necessary to calculate the constrained on capability of each step of the Unit s Offer price function in a Dispatch Hour Paragraph 66 of Schedule B sets out how this is done Paragraph 66 2 specifies the formula for determining how much of the third step of a Unit s Offer price function is constrained on 662 Theconstrained on capability of the third step of the Offer Price Function of a Unit in a Dispatch Hour shall be calculated in accordance with the following equations If OP a3 gt SMP and MQ gt OQ then CONC Min Max MQ MNDC 0 Max MQ OQ OQ 0 otherwise 0 ut3 where is the minimum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC B65 S _ AAKE 7 ESB INTERNATIONAL How do Constrained On Off payments Work In the following illustration none of the Offered capacity of step 3 of the Offer price function is constrained on because the M eter Quantity is not greater than the Offered quantity of the first and second steps Figure 19 Offer Price Function of a Unit DRS MWh Constrained
78. stem will be set by the regulatory authorities from time to time It is envisaged that the same fees structure will automatically apply to all users their specific fee being determined according to their type of use 3 2 4 Ancillary Services Agreement Ancillary services are those services provided principally by generators to ensure a stable and reliable power system Table 3 4 summarises the key elements including the services that are envisaged to be covered 10 ESB INTERNATIONAL nera 3595 Ga Ora were Nus Framework of Codes and Agreements Table 3 4 Summary of Ancillary Services Agreement Type of Document Commercial Agreement Objective Provision of all necessary system support services The Parties 1 the HTSO 2 generators and perhaps others providers such as interruptible load Coverage Will deal with the definition scheduling and payment for the following services 1 2 Reserve 3 Reactive Power 4 Black Start It is envisaged that initially at least these services will be provided on the basis of medium term contracts and that the first tranche of contracts would be at regulated terms Subsequently new contracts could be procured by open competitive tender if there is sufficient competition in the generation market The cost of the agreements would be recovered by the HTSO through the Uplift element of the PEC 3 2 5 TheAuthorisations The Law requires tha
79. system 4 2 Net Settlement In the STA and as indicated above all entities that sell electricity are known as Generators and all entities that buy electricity are known as Purchasers Suppliers in accordance with the Greek Electricity Law are both Purchasers and Generators Exporting Purchasers are also both Purchasers and Generators For simplicity in the description of the STA the roles of Purchaser and Generator are always separated All electricity generated is described as being sold through the STA and all electricity consumed is described as being purchased through the STA The HTSO keeps track of which parent entity owns each Participant and when it sends out invoices or makes payments it consolidates the transactions for each owner so that only one net invoice or 5 According to Article 24 of the Greek Electricity Law every authorised Supplier must own adequate generating capacity installed in a Member State of the EU and provide long term confirmation as to the necessary reserve capacity within the EU 6 When required and to the minimum extent possible a special division of the HTSO also participates in the STA It is known as the Special Participant and is able to Participate as both a Purchaser and a Generator as required Its involvement is minimal and is stated here only for completeness Its role is clearly defined and limited to the following two purposes e Very small generators located in Greece and exempt from the
80. t with some smaller exceptions all domestic participants in the electricity industry must obtain authorisations from the Ministry of Development on the basis of opinions from RAE The main elements that are envisaged for these authorisations are summarised in Table 3 5 ESB INTERNATIONAL nera sees ae ALKE e Framework of Codes and Agreements Table 3 5 Summary of Proposed Authorisations Type of Document Regulatory Instrument Objective To ensure effective control of entry to the industry and regulation of behaviour of participants The Parties Issued by Ministry of Development RAE To beheld by 1 the HTSO 2 the Transmission Owner 3 the Distribution Owner 4 all Generators except for smaller exemptions 5 all Suppliers except for some possible exemptions Coverage Coverage and terms vary from Authorisation to Authorisation Include requirements for compliance with Codes provision of information accounting etc and may indude other provisions such as price control participation in certain agreements etc There will be separate authorisations for the HTSO the transmission owner the distribution owner and operator suppliers and generators The key features will vary from caseto case but it is envisaged for example that these authorisations would be the means through which is enforced requirement on suppliers for generation ownership and reserve and price con
81. tion is constrained on 664 Theconstrained on capability of the first step of the Offer Price Function of aUnitin a Dispatch our shall be calculated in accordance with the following equations gt SMP jand MQ gt 0 then CONC Max MQ MNDC CONC 3 CONC 0 otherwise CONC 0 where is the minimum dispatch capability of Unit u in Dispatch Hour t pursuant to PEC B65 In the following illustration none of the Offered capacity of step 1 of the Offer price function is constrained on because the SM P is greater than the Offered price of the first step 52 mm Nu ESB INTERNATIONAL nera sess 5 AAKE How do Constrained On Off payments Work Figure 1111 Offer Price Function of a Unit DRS MWh BAM Constrained On Quantity of Step 1 is zero PEC B66 4 SMP Minimum Dispatch Capability Meter Quantity MNDC MQ Paragraph 67 specifies the formula for determining the Constrained On Payment for the Unit and all other Units owned by the corresponding Generator in the Dispatch H our 67 Determination of Constrained On Payments of a Unit Except as provided in PEC B69 and except if a Constrained Off Payment is payable in respect of a Unit in a Dispatch Hour pursuant to PEC B64 then a Constrained On Payment in respect if a Unit in a Dispatch Hour shall be calculated in accordance with the following equation 3
82. to the Participants The HTSO s costs induding its internal administrative costs and other costs are passed through to Participants in the Uplift charge 24 ESB INTERNATIONAL nera S B Nag Summary Description of Power Exchange Code 5 SUMMARY DESCRIPTION OF POWER EXCHANGE CODE The Power Exchange Code provides for the commercial operations of the System Trading Arrangements It consists of 5 parts the General Provisions and Schedules A through D Figure 5 1 Contents of Power Exchange Code GENERAL PROVISIONS 1 Definitions 2 Purpose 3 Persons and Participants 4 Market co ordination and Development Committee 5 Provision of Information by a Person amp HTSO 6 Roleof HTSO 7 Discontinuing Persons 8 Termination 9 Consequences of Default 10 Currency 11 Commencement Date and Term 12 Modification of the Power Exchange Code 16 Access to Power Exchange Code 14 Conduct of Settlement and Billing 15 Publication of a Calendar for Settlement and Billing 16 Security Cover 17 Audit of Settlement Software 18 Audit of the Power Exchange Code 19 Arbitration 20 Force M ajeure 21 Liability 22 Assignment 23 Notices 24 Confidentiality 25 Jurisdiction SCHEDULE A DEFINITIONS SCHEDULE PROCEDURES SCHEDULE C FORM OF ADDRESS AND CONTACT DETAILS SCHEDULE D SECURITY COVER 5 1 General Provisions The General Provisions establish the commercial framework
83. trol processes where appropriate 12 ESB INTERNATIONAL nera 3595 Ga e GE Summary of System Trading Arrangements 4 SUMMARY OF SYSTEM TRADING ARRANGEMENTS The implementation of the System Trading Arrangements STA introduces several important changes in the electricity sector Most notably it creates the mechanisms by which new Suppliers new generators international Participants and PPC can buy and sell electricity These mechanisms include procedures for scheduling and dispatching electricity generation and for determining a transparent and verifiable price at which imbalance energy trades The trading arrangements are designed to ensure that the Hellenic Transmission System Operator HTSO can operate the system in an efficient and reliable manner and that generators have an incentive through market prices System Marginal Prices or SMPs to follow its instructions The STA also gives generators market based incentives for production and investment It is designed to enable the efficient entry of private generators to meet the electricity needs of Eligible Customers without losing the benefits of the integration present in the existing system and without imposing large additional costs The largest Participants in the STA will initially be PPC generation and PPC supply but this may change as private suppliers and private generators become Participants The principal characteristics of the design of the STA in
84. ve entered into Transmission Connection Agreements but are not Participants will not be settled through the Power Exchange Code 71 ESB INTERNATIONAL nera 2688 Naa
85. ver the D ispatch D ay Paragraph 69 limits the Units in respect of which any Constrained On Payments or Constrained Off Payment may be made ESB INTERNATIONAL nera ses How do Constrained On Off payments Work 69 Exceptions to M aking of Constrained O n and Off Payments 1 HTSO shall make Constrained On Payments or Constrained Off Payments in respect of a U nit for any Dispatch H our of a Dispatch D ay in respect of which a the D eclared Information of the Unit is revised during the Dispatch D ay b M etering Data has not been supplied in respect of a Dispatch Hour in the Dispatch Day c the Daily Offer or any component of the Daily Offer of the Unit is revised during the Dispatch D ay or d the Unit is deemed to be non compliant with a Dispatch Instruction in accordance with the O perating Code at any time during the D ispatch D ay 2 HTSO shall make no Constrained O n Payments or Constrained O ff Payments in respect of Special Units Units in foreign countries or in respect of generating entities represented by the Special Participant 56 ESB INTERNATIONAL BLOK nera 52 AAK 7 How Are Settlement Quantities Determined 12 HOW ARE SETTLEMENT QUANTITIES DETERMINED Settlement Quantities are used in conjunction with SM Ps to determine the Energy Payments and Energy Charges of Participants Settlement Quantities are determined as a result of first
86. within which Persons must operate if they are to trade wholesale Energy in Greece The General Provisions identify ESB INTERNATIONAL nera sees 5 AAKE Summary Description of Power Exchange Code when a Person becomes bound by the terms of the Power Exchange Code and the basis on which a Person s rights under the Power Exchange Code may be revoked They also establish how much security a Person must provide and the terms on which a Person will be billed and or paid for their generation use of Energy The General Provisions also establish rules governing confidentiality and the resolution of any disputes that may arise under the Power Exchange Code 5 2 Schedule A Schedule A to the Power Exchange Code lists and defines the capitalised terms used throughout the Power Exchange Code Where a definition is taken from the Electricity Law Operating Code or other document reference is made to the source document This provides consistency of terms throughout the suite of documents that make up the STA thereby aiding user readability and understanding 5 3 Schedule B Schedule B is the heart of the Power Exchange Code It specifies the ways in which Participants buy and sell energy through the Power Exchange Code including the commercial metering requirements of generators and customers how meter readings are allocated to Participants and used in the settlement process to determine the quantities of energy bought and sold the way in
87. y which energy is metered settled and billed Paragraph 58 specifies the way in which Energy Charges and Energy Payments determined are transacted through the HTSO settlement accounts so as to be assigned to Participants 58 Account Transactions for Energy Charges and Energy Payments On the Calculation D ay in respect of aDispatch Day HTSO shall 18 debit the Energy Sales and Purchases Account and credit Participant s Participant Trading Account by the Participant s Energy Payment amount for that Dispatch Day and 2 credit the Energy Sales and Purchases Account and debit a Participant s Participant Trading Account by the Participant s Energy Charge amount for that Dispatch Day ESB INTERNATIONAL nera sees AAKE What Charges and Payments are Settled Under the Power Exchange Code Since the total of Energy Charges will not equal the total of Energy Payments in any given Dispatch Hour a transaction is made every day to the Uplift settlement account to clear the difference This transaction is described in Paragraph 59 15 2 Uplift Paragraph 29 2 specifies the categories of cost and payment that constitute Uplift and are settled under the Power Exchange Code They are Ancillary Services HTSO administration charges Interconnector net costs Special Unit costs Constrained On Payments Constrained Off Payments losses adjustments and additional charges other ite

Power Exchange Code User Guide Draft

Contents

Download Pdf Manuals

Related Search

Related Contents