Storage Connection requirements General Overview and implementation approach Belgian Working Group 1st December 2017 Aymen Chaouachi

Scope and implementation Overview General Provisions 1 Scope and implementation 2 Storage requirements Track Change 3

General Provisions 1 Notions de base sur le marché de l’électricité

Why a dedicated Storage Connection Requirement? RfG DCC HVDC Network codes Connection requirements Network Code compliance E&R Network Code SO Guidelines Storage inherent characteristics Fast ramping capabilities Cold-Load pickup during reconnection Storage Operation Modes Charging and discharging modes Active power control Except for pumped storage, Explicitly out of scope Electricity scenarios for BE 2050 Needs for Storage Requirements Drivers for dedicated Storage Requirements

Electric Energy Storage Types Mechanical Pumped Hydro* Compressed Air Flywheels Electrical Capacitors Magnetic coils Chemical Batteries Fuel cells Connected via SM Connected via Converters** * Covered in RfG ** Similar technical capabilities to PPM

General points of consideration Typically a storage system is a Controllable power injector or load behind a converter with similar characteristics to a PPM: The converter in this case can act as an inverter (discharging mode) or rectifier (charging mode) Constraints wise: No minimum regulating power Pmin (+) Very Fast ramping capabilities (+-) Minimum or maximum state of charge (-) Implementation of requirements within a dedicated section: Similar granularity as per the RfG SGUs Dedicated requirements in alignment with the RfG PPM capabilities Adaptations to take into consideration specific nature of storage and other NCs provisions (SO GL and E&R NCs)

Scope and implementation 2 Notions de base sur le marché de l’électricité

Storage System requirements: Scope Public Transmission network Gen = ~ POCC SPM Central Control Storage Park Module (SPM): An electric system composed of a single or multiple electrical storage units capable of storing, delivering electrical energy into a single electrical point of connection. Possible Operational modes   Charging Source Discharging sink Case 1 Public Network Case2 Local facility (local demand) Case 3 Local facility (local generation) Case 4 Not applicable to emergency generation operating in parallel less than five minutes per calendar month while the system is in normal system state; Cover both permanently or temporarily connected batteries as Vehicle2Grid applications.

New set of definitions – To be used and defined in the FGC General Storage Park Module (SPM) An electric system composed of a single or multiple electrical storage units capable of storing, delivering electrical energy into a single electrical point of connection. Characteristics Pcmax: Allowable maximum charging at the point of common coupling. Pdmax: Allowable maximum discharging at the point of common coupling. Prated: The highest active power which the SPM is designed to deliver or absorb at the point of common coupling (used to determine the SPM Type). State Of Charge (SOC): Is the measure of the amount of capacity remaining expressed in percentage points (0% = empty; 100% = full). Minimum/Maximum State of Charge: Are the limitation in term of storage capabilities Operation Charging Mode / Discharging Mode Nominal charging and discharging rates Fast charging and discharging rates (e.g. EV charging stations)

Requirements mapping Very Common Common >0.25 MW Rare >25 MW Alignment with C10/11 Type A PGM Type A SPM Very Common Type B PPM Type B SPM Common >0.25 MW Type C PPM Type C SPM Rare >25 MW Type D PPM Type D SPM Very rare >75 MW Voltage Connection level is not considered in the determination of the Storage Type Requirements Type shifting

Storage requirements Track Change 2 Notions de base sur le marché de l’électricité

Approach for trach-changes Similar characteristics to a PPM: full new set of technical requirements coming from the NC and not yet in the FGC Not an isolated chapter in the FGC => not the approach of having a “full grid code for storage” Use of references to technical requirements to PPM or PGM, when appropriate : to limit double writing of the same rule To refer indirectly to the NC RfG, when the PPM or PGM articles are referring to the RfG Specific Sub-Section devoted for storage, to add readability in the FGC Limited to technical requirements

Type A: Track Change RfG Reference Requirement Adaptation [Art. 13-4] Admissible maximum power reduction with falling frequency Not applicable [Art. 13 (2)(b)] Use of automatic disconnection and reconnection (LFSMO) [Art. 13 (2)] Limited frequency sensitive mode – Overfrequency Yes [Art 13-6] Logical interface to cease active power injection [Art 13.7] Conditions for automatic connection to the network [Art. 15(2)(c)] Limited frequency sensitive mode – Underfrequency Yes* [Art 15.6(e)] Ramping Limits * Applicable to all Type A, B, C and D

Type B: Track Change RfG Reference Requirement Adaptation Vs RfG [Art. 14-2 (a)]: Reduce active power output Yes [Art 14-4] Conditions for automatic re-connection to the network [Art 20-2(a)] Reactive Power Capabilities [Article 20 (2) b/c] Fast fault current injection Yes* [Article 20(3)] Priority to active or reactive power contribution * Optional requirement

Type C: Track Change RfG Reference Requirement Adaptation Vs RfG [Art 15.2.(a)] Time period for frequency stability to be reached Yes [Art 21 (3)(a-c)] Reactive power capabilities [Art 15 (2) (d)] FSM requirements Reference to the general framework [Art 15.2.(e)] Specifications of the Frequency Restoration Control