Power Potential: A New Market for Reactive Power Dr. Biljana Stojkovska, National Grid Dr. Ali Ahmadi, UK Power Networks LCNI, Low Carbon and Innovation Conference, 6-7 December 2017, Telford

Power Potential - Key Facts PROJECT PARTNERS: Funding Mechanism: Ofgem Network Innovation Competition (NIC) Project Lead/funding licensee: National Grid Start date: January 2017 End Date: December 2019 1

Area of Focus 2

Why Power Potential? 3

The How ? Technical solution Dynamic voltage control from DER Active Power Support for constraint management and system balancing Commercial solution Establishing new reactive power market from DER Prove of the concept of the whole system approach Business Change Concept of transition from DNO to DSO 4

Wind Farm Central Controller Copying an idea from offshore wind farms Wind Farm Central Controller 5

Power Potential Operation GSP GSP DERMS GSP GSP 6

Power Potential Video 7

Power Potential Approach 8

Distribution/Transmission System Coordination and Control Constraint Headroom/Footroom MW and Mvar Service Cost Curve Constraint Flows DER MW setpoints Sensitivities National Grid GSP DNO Thermal DERMS Target voltage Direct DER Dispatch Canterbury North SGTs PX route ANM DERMS is providing visibility and availability of DER services to National Grid. DERMS is avoiding conflicts of services by informing National Grid of the constraint headroom & footroom, hence the direct dispatch of other DER Services sitting behind ANM schemes are not nullified by ANM operation. Centralised dispatch of distribution resources through a centralised platform which has full visibility of DNO network. In other words DERMS is acting as a gateway to accessing services on the distribution network. These are all significant steps towards a whole system strategy in UK and becoming a DSO. Dynamic Voltage Stability: 1-5secs I²X losses over 224km circuit High probability when levels of DG are high, HVDCs importing and circuits are lightly loaded High Volts: Sec, min, hrs Decline in Q/P ratio Increase in DG no longer confines this to an overnight scenario Thermal: mins Network capacity is insufficient to permit full output under maintenance conditions across the area following a further double circuit fault ANM Controlled DER STOR DER Power Potential DER 9

Voltage Response Example Service Mode – Low Voltage Occurs NGET Control Room GSP 400/132kV Low Voltage NGET receives the service at the GSP and is active until further instruction B UKPN Control Room ANM → Constraint Headroom → DERMS ANM PP Software measures the V drop and calculates further setpoints to achieve maximum response as requested at least cost. DER1 Mvar response Power Potential Software DER2 Mvar response Additional V-droop setpoints The Power Potential Distributed Energy Resource Management System (DERMS) will calculate the optimum Distributed Energy Resource (DER) production dispatch that satisfies the dynamic voltage and active power services request from National Grid at the lowest cost. DERMS will manage other conflict of services such as STOR, Frequency Response and Reserve Services and avoid dispatching services behind Active Network Management (ANM) schemes prior to resolving distribution constraints. This project will significantly enhance Transmission and Distribution systems coordination and control. It will open up new revenue streams and reduce constraints on renewable energy providers while giving National Grid additional tools to manage transmission system constraints. These are all significant steps towards a whole system strategy in United Kingdom. 132/33kV A 132/33kV DER self-dispatch as per changes in voltage in their Point of Connection Distributed Energy Resources Issues MW setpoint ANM DER3 Mvar response 33/11kV DERMS 10

DER Engagement & Active Participants Power Potential team is actively engaged with DER developers: Webinar 1-to-1 dissemination events 1-to-1 surgeries Issuing the DER Technical Characteristic Document Developing MW and MVAr effectiveness heatmap Over recent period we have held a series of one to one discussions with DERs to engage on participation in Power Potential.   The DERs engaged with are: Aggregators / (portfolio of CHP and diesel) Batteries Solar Offshore wind farm   The key themes from our meetings have been: Generally positive atmosphere – it has been beneficial from both a DER and project perspective to meet face to face and discuss individual projects Total approximate volume for project discussed is 130 MW. Mvar volume is less certain as some parties have not previously considered their reactive capability A number of parties have raised interest about similar services in other areas of GB, indicating a general appetite for participation in reactive markets for DERs Our next steps following this phase of engagement are: Publish summary of bilateral discussions on Power Potential website and follow up with actions taken away from each meeting Follow up meeting with other larger players in the project area, in order to increase potential volume participation Engage with the Solar Trade Association and Renewable Energy Association Define what success looks like for DER participation (building on as much as possible DER providers covering a diverse range of technologies 11

Customers & Stakeholder Benefits The project will : enable more DER customers to connect in the South East providing services to National Grid, reducing operating costs accessing additional revenue streams for DER defer network reinforcement needs in the transmission system When deployed, Power Potential can deliver: 3720 MW of additional generation in the area by 2050 Savings of £412m for UK consumers by 2050 12

Where we are? Study results done  High Level Design  Technical Detail Design Commercial Detail Design Engagement with DERs Academic research (Imperial College & Cambridge University) 13