Remedial Actions
European Union Electricity Market Glossary

 


 

 

Remedial Action is any measure applied by a Transmission System Operator (TSO) or several TSOs, manually or automatically, in order to maintain operational securityas well as to relieve physical congestion on their networks.

 

Remedial Actions serve, in particular, to fulfil the (N-1)-Criterion and to maintain operational security limits.

 

ENTSO-E underlines (Supporting Document for the Network Code on Emergency and Restoration, ENTSO-E, 25 March 2015, p. 23) Remedial Actions are being mainly dedicated to Normal State and Alert State whereas System Defence Plan measures are to be used specifically in Emergency State when (N-1)-Criterion and operational security limits are already violated.


Remedial Actions may include, but are not limited to the following:


- re-dispatching;

 

- countertrading;

 

- Demand Side Response,

 

- increase/decrease energy storage;


- topology changes in the network;


- adjusting flows by phase shifters and other flow controlling devices;


- use of reactive power devices (tap-changers, reactors, capacitor banks, SVC, etc.);


- request (or control if available) additional voltage/reactive support from power plants;


- HVDC Systems active and reactive power control; and


- System Protection Schemes actions.

 

Remedial Actions are prepared and activated by the TSOs where the level of reactive power ancillary services is not sufficient for maintaining operational security (Article 109(3) of the Network Code on System Operation).

In such a case the TSO informs the neighbouring TSOs.

 

The detailed regulatory framework for Remedial Actions is laid down in Articles 20 - 23 of the Network Code on System Operation (see box below). 

 

Pursuant to the ENTSO-E Supporting Document for the Network Code on Operational Security of 24 September 2013 2nd Edition Final (p. 72) Remedial Actions can be categorised as the pre-fault (i.e. preventive) or post-fault (i.e. corrective or curative).

 

Another way Remedial Actions can be divided is whether they are applied within one TSO area or between interconnected TSOs.

 

 

Preventive Remedial Actions

 

 

Preventive Remedial Actions are used normally in operational planning or scheduling stage to maintain system in Normal State in the coming operational situation and to prevent propagation of disturbance outside the TSO ́s Responsibility Area.

 

Preventive Remedial Actions may include, but are not limited to the following:


- re-dispatching or counter trade actions;


- topology changes in the network;


- adjusting flows by phase shifters and other flow controlling devices;


- manual switching of reactive power devices (tap-changers, reactors, capacitor banks, SVC, etc.) or changing the set-point level of their controllers;


- request (or control if available) additional voltage/reactive support from power plants;


- enabling available System Protection Schemes.

 

 

Corrective Remedial Actions

 

 

Corrective Remedial Actions are actions, which will be implemented immediately or relatively soon after an occurrence of a contingency, which leads to a state differing from Normal State.

 

With the corrective Remedial Action the system will be returned back to Normal State.

 

Corrective Remedial Actions may include, but are not limited to the following:


- re-dispatching or counter trade actions including activation of TSO reserves;


- control of reactive power devices (tap-changers, reactors, capacitor banks, SVC, etc.);


- activation of additional voltage/reactive support from power plants;


- emergency power control of HVDC links of other power controlling devices;


- system protection schemes actions e.g. change of network topology, trip of production or trip load depending on protection specification.

 

 

Remedial Actions' costs

 

 

Some Remedial Actions do not result in significant costs (e.g. changing grid topology), while others (e.g. re-dispatching, counter-trading and curtailment of allocated capacities) come at a cost to the system or to TSOs.

 

The costs of Remedial Actions are recovered by TSOs either via network tariffs, or, in a few cases such as Austria and Portugal, via congestion rents.

 

In both cases, costs are socialised and directly or indirectly affect the incontestable part of the end-consumers' bill and therefore limit the scope for competition in the wholesale and retail markets (ACER/CEER Annual Report on the Results of Monitoring the Internal Electricity Markets in 2015, September 2016, p. 26).

 

The Remedial Actions costs for 2015 for individual EU Member States have been set out in the said Report (p. 27) in the tabular form (including the breakdown for the type of the Remedial Action).

 

When redispatching and countertrading to restore system security are not available, TSOs may curtail allocated capacities and owners of the transmission rights (TRs) have to be compensated.

 

In the event of force majeure after the day-ahead firmness deadline, market participants are entitled to the reimbursement of the price paid for the capacities during the explicit allocation process.

 

In an emergency situation, market participants are entitled to compensation equal to the market price difference, in the relevant time-frame, between the bidding zones concerned (with the exception of SK-PL border, where special conditions apply).

 

When long-term transmission rights (LTTRs) are curtailed prior to the day-ahead firmness deadline, the Network Code on Forward Capacity Allocation (FCA) envisages that the holders should be compensated by the relevant TSOs with the day-ahead market price spread of relevant markets.

 

However, the TSOs on a bidding zone border are allowed to cap the total compensation to be paid in a period to the total amount of congestion income collected on the relevant bidding zone border in the same period (i.e. on a yearly basis or on a monthly basis in the case of HVDC interconnectors).

 

The cost of curtailments is usually divided between the TSOs according to the same sharing key that is used to split the congestion rent.

 

ACER Recommendation No 2/2016 of 14.11.2016 on the common capacity calculation and redispatching and countertrading cost sharing methodologies observes (p. 7) the activation of remedial actions is often not coordinated, thus not optimised. Coordinated remedial actions are still an exception rather than the rule. The costs of remedial actions are most often paid by the TSOs facing congestion problems (i.e. requester-pays principle), rather than the ones causing them (i.e. polluter-pays principle).

 

 

Remedial Actions in the Winter Energy Package

 

 

The so-called 'Winter Energy Package' envisions the rule that the transmission system operators must not limit the volume of interconnection capacity to be made available to other market participants in order to solve congestion inside their own control area or as a means of managing flows on a border between two control areas observed even without any transaction, i.e. flows over control areas caused by origin and destination within one control area.

 

Derogation from this principle may be granted in exceptional circumstances only (Article 14(7) of the Proposal for a Regulation of the European Parliament and of the Council on the internal market for electricity (recast), 30.11.2016, COM(2016) 861 final 2016/0379 (COD)).

 

Referring to these proposals, ENTSO-E in the policy statement of 15 March 2017 "Key Recommendations for the Clean Energy Package" heavily criticised the European Commission's propositions, in particular, ENTSO-E said: "the requirements on TSOs capacity calculation to ignore internal congestions and loop flows and instead use costly remedial actions to increase cross-border capacity would lead to outcomes not reflecting the physical reality of European grids and significantly increase congestion management costs to be paid by end-consumers via transmission tariffs (Art. 14)."


 

In the document "Clean Energy Package: Promising market proposals, but some issues to be solved" of 15 March 2017, ENTSO-E expressed reservations regarding the fact that the European Commission's proposals in the said draft Regulation require no consideration of internal congestions nor loop flows within the capacity calculation process, and, in addition, they impose an obligation on TSOs to use preventive re-dispatch and countertrading to maximise available cross-border capacity.

 

"These provisions would oblige TSOs to ignore the physical flows that are an inherent part of the effective capacity calculation, increase the differences between the system reality on one side and the commercial exchanges on the other," ENTSO-E said.

 

According to the ENTSO-E the said draft provisions would lead to higher re-dispatch costs and risks related to possible unavailability or inexistence of necessary Remedial Actions to cope with congestions. 


  

 

 

Network Code on System Operation, Articles 20 - 23

 

Article 20
Remedial actions in system operation


1.   Each TSO shall endeavour to ensure that its transmission system remains in the normal state and shall be responsible for managing operational security violations. To achieve that objective, each TSO shall design, prepare and activate remedial actions taking into account their availability, the time and resources needed for their activation and any conditions external to the transmission system which are relevant for each remedial action.


2.   The remedial actions used by TSOs in system operation in accordance with paragraph 1 and with Articles 21 to 23 of this Regulation shall be consistent with the remedial actions taken into account in capacity calculation in accordance with Article 25 of Regulation (EU) 2015/1222.


Article 21
Principles and criteria applicable to remedial actions


1.   Each TSO shall apply the following principles when activating and coordinating remedial actions in accordance with Article 23:


(a) for operational security violations which do not need to be managed in a coordinated way, a TSO shall design, prepare and activate remedial actions to restore the system to the normal state and to prevent the propagation of the alert or emergency state outside of the TSO's control area from the categories defined in Article 22;


(b) for operational security violations which need to be managed in a coordinated way, a TSO shall design, prepare and activate remedial actions in coordination with other concerned TSOs, following the methodology for the preparation of remedial actions in a coordinated way under Article 76(1)(b) and taking into account the recommendation of a regional security coordinator in accordance with Article 78(4).


2.   When selecting the appropriate remedial actions, each TSO shall apply the following criteria:


(a) activate the most effective and economically efficient remedial actions;


(b) activate remedial actions as close as possible to real-time taking into account the expected time of activation and the urgency of the system operation situation they intend to resolve;


(c) consider the risks of failures in applying the available remedial actions and their impact on operational security such as:
(i) the risks of failure or short-circuit caused by topology changes;
(ii) the risks of outages caused by active or reactive power changes on power generating modules or demand facilities; and
(iii) the risks of malfunction caused by equipment behaviour;


(d) give preference to remedial actions which make available the largest cross-zonal capacity for capacity allocation, while satisfying all operational security limits.


Article 22
Categories of remedial actions


1.   Each TSO shall use the following categories of remedial actions:


(a) modify the duration of a planned outage or return to service transmission system elements to achieve the operational availability of those transmission system elements;


(b) actively impact power flows by means of:
(i) tap changes of the power transformers;
(ii) tap changes of the phase-shifting transformers;
(iii) modifying topologies;


(c) control voltage and manage reactive power by means of:
(i) tap changes of the power transformers;
(ii) switching of the capacitors and reactors;
(iii) switching of the power-electronics-based devices used for voltage and reactive power management;
(iv) instructing transmission-connected DSOs and significant grid users to block automatic voltage and reactive power control of transformers or to activate on their facilities the remedial actions set out in points (i) to (iii) if voltage deterioration jeopardises operational security or threatens to lead to a voltage collapse in a transmission system;
(v) requesting the change of reactive power output or voltage setpoint of the transmission-connected synchronous power generating modules;
(vi) requesting the change of reactive power output of the converters of transmission-connected non-synchronous power generating modules;


(d) re-calculate day-ahead and intraday cross-zonal capacities in accordance with Regulation (EU) 2015/1222;


(e) redispatch transmission or distribution-connected system users within the TSO's control area, between two or more TSOs;


(f) countertrade between two or more bidding zones;


(g) adjust active power flows through HVDC systems;


(h) activate frequency deviation management procedures;

(i) curtail, pursuant to Article 16(2) of Regulation (EC) No 714/2009, the already allocated cross-zonal capacity in an emergency situation where using that capacity endangers operational security, all TSOs at a given interconnector agree to such adjustment, and re-dispatching or countertrading is not possible; and
(j) where applicable, include the normal or alert state, manually controlled load-shedding.


2.   Where necessary and justified in order to maintain operational security, each TSO may prepare and activate additional remedial actions. The TSO shall report and justify those instances to the relevant regulatory authority and, where applicable, the Member State, at least once every year, after the activation of the additional remedial actions. The relevant reports and justifications shall also be published. The European Commission or the Agency may request the relevant regulatory authority to provide additional information concerning the activation of additional remedial actions in those instances where they affect a neighbouring transmission system.


Article 23
Preparation, activation and coordination of remedial actions


1.   Each TSO shall prepare and activate remedial actions in accordance with the criteria set out in Article 21(2) to prevent the system state from deteriorating on the basis of the following elements:
(a) the monitoring and determination of system states in accordance with Article 19;
(b) the contingency analysis in real-time operation in accordance with Article 34; and
(c) the contingency analysis in operational planning in accordance with Article 72.


2.   When preparing and activating a remedial action, including redispatching or countertrading pursuant to Articles 25 and 35 of Regulation (EU) 2015/1222, or a procedure of a TSO's system defence plan which affects other TSOs, the relevant TSO shall assess, in coordination with the TSOs concerned, the impact of such remedial action or measure within and outside of its control area, in accordance with Article 75(1), Article 76(1)(b) and Article 78(1), (2) and (4) and shall provide the TSOs concerned with the information about this impact.


3.   When preparing and activating remedial actions which have an impact on the transmission-connected SGUs and DSOs, each TSO shall, if its transmission system is in normal or alert state, assess the impact of such remedial actions in coordination with the affected SGUs and DSOs and select remedial actions that contribute to maintaining normal state and secure operation of all involved parties. Each affected SGU and DSO shall provide to the TSO all necessary information for this coordination.


4.   When preparing and activating remedial actions each TSO shall, if its transmission system is not in normal or alert state, coordinate to the extent possible such remedial actions with the affected transmission-connected SGUs and DSOs to maintain the operational security and the integrity of the transmission system.

When a TSO activates a remedial action each impacted transmission-connected significant grid user and DSO shall execute the instructions given by the TSO.


5.   Where constraints have only consequences on the local state within the TSO's control area and the operational security violation does not need to be managed in a coordinated way, the TSO responsible for its management may decide not to activate remedial actions with costs to relieve them.

 

 

 

 

 

IMG 0744

    Documentation    

 

 

 

Network Code on System Operation, Articles 20 - 23

 

Network Code on Forward Capacity Allocation (FCA)

 

Proposal for a Regulation of the European Parliament and of the Council on the internal market for electricity (recast), 30.11.2016, COM(2016) 861 final 2016/0379 (COD))

 

Supporting Document for the Network Code on Emergency and Restoration, ENTSO-E, 25 March 2015, p. 23

 

ENTSO-E Supporting Document for the Network Code on Operational Security of 24 September 2013 2nd Edition Final, p. 72

 

ACER Recommendation No 2/2016 of 14.11.2016 on the common capacity calculation and redispatching and countertrading cost sharing methodologies

 

ACER/CEER Annual Report on the Results of Monitoring the Internal Electricity Markets in 2015, September 2016, p. 26

 

 

 

  

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    Links    

 

 

 

 

 Key Recommendations for the Clean Energy Package

 

 Clean Energy Package: Promising market proposals, but some issues to be solved of 15 March 2017

 

 

 

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Last Updated on Thursday, 21 September 2017 18:32
 

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