CONGESTION MANAGEMENT POLICY

Transcription

1 1 (8) CONGESTION MANAGEMENT POLICY Contents 1 General Principles of congestion management Congestion management in the Finnish transmission grid Normal situation Planned outages Disturbance and fault situations Congestion management on the Nordic connections Normal situation Planned outages Disturbance and fault situations Congestion management on the Estonian connections Normal situation Planned outages Disturbance and fault situations Congestion management on Russian connections Normal situation Planned outages Disturbance and fault situations... 8

2 2 (8) 1 General This document defines Fingrid s congestion management policy. This guideline is based on the principles for the promotion of the electricity market and for system security management, accepted by Fingrid s Board of Directors. A limited volume of electricity conforming to the system security criteria can be transmitted in a grid. This is referred to as the transmission capacity. Congestion management ensures that the power flows remain within the transmission capacity. 2 Principles of congestion management Fingrid s congestion management is guided by systematic planning and predictability. As high transmission capacity as possible is made available to the customers and the electricity market without compromising system security. Finland constitutes one bidding zone in the electricity market. Fingrid agrees bilaterally with its customers on their transmission rights. EC Regulation 714/2009 together with the guidelines and network codes in accordance with it define the framework for congestion management. The Finnish transmission grid is connected to the transmission systems in Sweden, Norway, Estonia and Russia. The market designs of the electricity market in these countries differ from each other, resulting in different approaches in congestion management on the interconnections between these countries and Finland. Congestions on the interconnections are managed primarily by means of implicit auctions, where the price of energy is defined simultaneously in the various bidding zones, taking into account the transmission capacity between the bidding zones, and secondarily by auctioning transmission rights within the available transmission capacity. The transmission capacity made available to the market is confirmed and publicised in accordance with time schedules agreed in advance with power exchanges (PXs) and other transmission system operators (TSOs). Transmission outages which influence the transmission capacity are planned costeffectively and in view of the overall situation to take place at times when the outages inconvenience the customers and the electricity market as little as possible, taking the technical boundary conditions into account. Outages related to construction projects and maintenance are carried out in accordance with the outage plan of the grid, and outages are only postponed to coming years for well-justified reasons. The transmission situation is monitored during each hour of operation, and action is taken wherever necessary if the power flows are going to exceed the transmission capacity. Firmness of confirmed electricity transactions are secured by adjusting, wherever necessary, the operating situation of the grid by means of counter trade to correspond to the technical transmission capacity of the grid. Counter trade utilises the available resources in an order determined by cost-effectiveness and appropriateness.

3 3 (8) In the event of force majeure, Fingrid has the right to restrict the transmission service or to interrupt it immediately. 3 Congestion management in the Finnish transmission grid Fingrid uses connection agreements and main grid contracts to agree with a customer connected to the transmission grid on the customer s right to transmit electricity and on the potential restrictions of the transmission rights. In the operation of the 400 kv network and 400 kv transformers, the management of faults is in accordance with the N-1 criterion. At the 400 kv voltage level, a single fault in the grid or at a power plant shall not result in restrictions in the transmission service to customers. Nevertheless, there are extraordinary situations (for example during planned outages and when system protection is activated), where restrictions to the transmission service cannot be avoided. In these cases, however, in accordance with the dimensioning rules, only local consequences are allowed, the power system shall remain stable, and the loading of the grid components following a fault shall not result in the activation of protection, which expands the fault. The local consequences have not been itemised in the dimensioning rules, but for example in the following cases the consequences are considered to be larger than local consequences: the disturbance extends to an area which in practice is fed from more than one 400 kv substation the disturbance influences a large number of customers and consumers (for example the Helsinki area), or the disconnected power is hundreds of megawatts the disturbance causes considerable economic losses to electricity users Local consequences of faults are permitted in the 110 kv and 220 kv networks, and in many cases it may be impossible to prevent such consequences for example during outages. The objective is to minimise the risk and inconvenience through the careful planning and timing of the outage. If a fault in the 110 kv or 220 kv network can have consequences which cannot be regarded as local (see examples above), measures identical with the case of the 400 kv network are taken. 3.1 Normal situation In a normal situation, the transmission restrictions are removed by means of counter trade if counter trade resources are available. The transmission capacity between Southern and Northern Finland is occasionally insufficient for the transmission needs of the market. The restricting part of the grid is situated at the intersection south of the river Oulujoki, and it is referred to as P1. In a normal grid operation situation, counter trade is used in congestion management at the P1 intersection, as follows:

4 4 (8) If a forecast drawn up on the day before suggests that the power flows at the intersection are no more than 100 MW higher than the transmission capacity, preparations are made to conduct counter trade, and the capacity made available to the Elspot market is not restricted. If the need for counter trade is 100 to 300 MW, counter trade is used if reasonably priced counter trade resources are available. If not, foreign trade of electricity between Finland and Northern Sweden is restricted. In assessing the reasonableness of the prices of resources, the counter trade costs are compared to the additional costs caused by restrictions in the foreign trade of electricity in the market area from the point of view of socio-economic welfare. If the need for counter trade is over 300 MW, the foreign trade of electricity between Finland and Northern Sweden is restricted for the portion exceeding 300 MW. 3.2 Planned outages Fingrid has the right to restrict or interrupt the grid service because of the maintenance, repair, modification, inspection or other corresponding work on its grid after it has first negotiated on the restriction or interruption with a customer connected to the grid. If electricity transmission at a customer s connection point has to be restricted or interrupted in such a case, no compensation is paid to the customer due to the energy not produced or consumed because of this. The timing of an outage required by maintenance, repair, modification, inspection and other corresponding work must be agreed with the customer in advance. When agreeing on the timing of the outage, the customer s needs shall be taken into account wherever possible, minimising the inconvenience inflicted on the customer. If necessary, the outage can be scheduled for example for a weekend or at night if this gives distinct benefits to the customer and if Fingrid s work can be carried out also in this case at reasonable additional costs and without compromising occupational safety. Fingrid plans the outage-related arrangements in co-operation with the customer and takes care of the execution of the measures in co-operation with the customer so that the outage is as short as possible. Each party is responsible for the operation measures on their own devices and for their own outage costs. Fingrid co-ordinates and maintains a transmission outage plan for the main grid. During planned outages in the 400 kv network, system security is ensured wherever necessary by means of counter trade if reasonably-priced counter trade resources are available. If not, system security is secured by restricting the transmission capacity on the cross-border interconnections or by restricting power flows within Finland. As regards the 220 kv and 110 kv network, the adequacy of the transmission capacity is ensured by the proper timing of the outage or by agreeing on the transmission restriction or interruption with a customer connected to the network in question. If the outage is in Fingrid s grid in a location other than the customer s connection point or on lines connected to it, the customer s transmission opportunities in the grid are ensured

5 5 (8) wherever necessary by means of counter trade, if reasonably-priced counter trade resources are available. In assessing the reasonableness of the counter trade costs in outage situations, the counter trade costs can be compared to the inconvenience inflicted by the transmission restriction or interruption in question on the customers. 3.3 Disturbance and fault situations System security in the grid is ensured wherever necessary by means of counter trade until the end of the next day of operation if counter trade resources are available and if there is no force majeure. If the transmission service needs to be restricted in disturbance or fault situations, there is no compensation to individual customers due to the restriction. 4 Congestion management on the Nordic connections The transmission capacity of the interconnections between Finland and Sweden is made available to the electricity market through the Elspot and Elbas markets of the Nordic power exchange (Nord Pool Spot). The Elspot market follows the principle of implicit auction, where the price of energy in the various bidding zones is determined simultaneously, taking into account the transmission capacity between the bidding zones. Any capacity not used in the Elspot market is offered to the Elbas market, where trading is continuous within the available transmission capacity. The power flows within an hour of operation are optimised between the northern and southern interconnections between Finland and Sweden on the basis of the operating situation of the power system. The interconnection between Finland and Norway is used for securing regional electricity transmission in Northern Norway. The transit power flows on the inter connections between Finland and Sweden, caused by the connection to Norway, are taken into account when transmission capacity is allocated to the market. 4.1 Normal situation In a normal situation, the technical transmission capacity less the reliability margin is offered to the Elspot market on the inter connections between Finland and Sweden. A reliability margin is only used on the alternating current interconnections between Finland and bidding zone SE1 in Sweden. The transmission capacity is agreed with Svenska Kraftnät before the capacity is notified to the power exchange for publication. The transmission capacity offered to the Elbas market is determined after the acceptance of Elspot transactions to conform to the technical transmission capacity, taking the reliability margin into account. Power flows exceeding the transmission capacity because of a forecast error of the market parties is adjusted away during the hour of operation by using the regulation power market. The adjustment is made proactively so that the technical transmission capacity is not exceeded.

6 6 (8) 4.2 Planned outages During planned outages, the technical transmission capacity corresponding to the outage situation less the reliability margin is offered to the market. The transmission capacity during a planned outage is notified to the market not later than six weeks prior to the outage. In co-operation with Svenska Kraftnät, the objective is to schedule the outages to coincide with the outages planned by SvK so that the outages have a minimum impact on the market. If the emergence of a price difference between Finnish and Swedish bidding zones during planned outages seems likely, the market impacts caused by the outages are reduced wherever possible through means such as shortening the duration of outages. Counter trade is not used for maintaining the transmission capacity offered to the market during planned outages. Transmission capacity following an outage which finishes sooner than planned is offered to the Elbas market. 4.3 Disturbance and fault situations Transactions confirmed in the Elspot and Elbas markets are ensured wherever necessary by means of counter trade until the end of the next day of operation unless there is a force majeure. The transmission capacity made available to the market is restricted by a volume corresponding to the impact of the disturbance or fault situation. When transmission capacity is allocated to the Elbas market, the impact of the capacity on the counter trade needs is taken into account. 5 Congestion management on the Estonian connections The transmission capacity of the interconnections between Finland and Estonia is made available to the electricity market through the Elspot and Elbas markets of the Nordic power exchange. 5.1 Normal situation In a normal situation, the entire transmission capacity of the interconnections between Finland and Estonia is offered to the Elspot market. The transmission capacity is agreed with Elering before the capacity is notified to the power exchange for publication. The transmission capacity offered to the Elbas market is determined after the acceptance of Elspot transactions, taking the power flows caused by Elspot transactions into account. 5.2 Planned outages Only some of the transmission capacity is available during planned outages. The transmission capacity during a planned outage is notified to the market not later than six weeks prior to the outage.

7 7 (8) The objective is to schedule the outages to periods of time where the outages have a minimum impact on the market. Counter trade is not used for maintaining the capacity offered to the market during planned outages. Transmission capacity following an outage which finishes sooner than planned is offered to the Elbas market. 5.3 Disturbance and fault situations Transactions confirmed in the Elspot and Elbas markets are ensured wherever necessary by means of counter trade until the end of the next day of operation unless there is a force majeure. The transmission capacity made available to the market is restricted by a volume corresponding to the impact of the disturbance or fault situation. When transmission capacity is allocated to the Elbas market, the impact of the capacity on the counter trade needs is taken into account. 6 Congestion management on Russian connections Electricity can be transmitted on the 400 kv inter connections from Russia by customers who have made an agreement on a transmission right with Fingrid to conduct either bilateral trade or direct power exchange trade and who have made an agreement on energy purchases with a Russian organisation responsible for electricity sales. The two 110 kv lines connected to Fingrid s grid from Russia are not owned by Fingrid, and the owners of the said connections are responsible for transmission on them. As far as congestion management is concerned, these 110 kv connections are handled like any other customers connected to the grid. 6.1 Normal situation Fingrid sells transmission rights up to the normal-state continuous import volume, with the exception of volumes reserved for system operation purposes. A customer engaged in bilateral trade notifies its transmission programme and any changes to it in accordance with an agreed time schedule. 6.2 Planned outages Fingrid restricts imports during outages on the Russian interconnection or in the network immediately adjacent to it in Finland (Yllikkälä and Kymi substations as well as Fingrid s lines from them, including the bays towards Yllikkälä and Kymi at the opposite substations). During a planned outage, the transmission programmes of all importers are restricted in proportion to the transmission programmes, with the restrictions focused primarily on bilateral trade. Fingrid together with the Russian party agrees on the timing of situations concerning the Russian transmission connections planned in advance, such as annual maintenance.

8 8 (8) Fingrid informs the customers and the market of transmission restrictions related to such situations well in advance. The objective is to schedule maintenance work in the nearby grid in Finland to coincide with maintenance on the Vyborg link and at the North-Western Plant in Russia. 6.3 Disturbance and fault situations Fingrid restricts imports during disturbance and fault situations on the Russian interconnection or in the nearby network in Finland (Yllikkälä and Kymi substations as well as Fingrid s lines from them, including the bays towards Yllikkälä and Kymi at the opposite substations). During an hour of operation subject to a restriction, the transmission programmes of all importers are restricted in proportion to the transmission programmes, with the restrictions focused primarily on bilateral trade. If the disturbance or fault situation is located elsewhere in Fingrid s grid, the procedure presented under item 3.3 is applied to customers connected to the grid. Imports from Russia can be limited in order to guarantee system security.