1.  2012. UK Power Networks. All rights reserved Demonstrating the benefits of energy storage on an 11 kV Distribution Network Matthieu Michel – Technology Innovation and Co-ordination Manager

2.  2012. UK Power Networks. All rights reserved Validate the capabilities of a Li-ion Energy Storage System (ESS) Demonstrate load-shifting and other interventions within the limits of the device 200 kW, 1 hour discharge duration 600 kW, short durations Evaluate the network benefits: accommodate additional demand and generation Understand the potential lifetime of the device Presentation: Early results from Operation of the device Key considerations: Efficiency, Losses, cost of energy Real powerReactive power Power ratingFinite (nom 200 kW)Finite (nom 600 kVAr) DurationFinite (nom 1hr)Unlimited Project Objectives:

3.  2012. UK Power Networks. All rights reserved Progress Highlights: The storage device has operated as a STATCOM since commissioning (April 2011) Exchanges of real power have started (May 2012) Network diagram Martham Primary Ormesby Primary Hemsby (Energy Storage System) Wind farm (10 turbines) 2.25MW Site where Additional monitoring is being installed

4.  2012. UK Power Networks. All rights reserved Operation: STATCOM Voltage at Hemsby without ESS (simulated data) Voltage at Hemsby with ESS (Simulated using real data) 18/04 19/04 20/04 Windfarm Output ESS Reactive Power Low Voltage triggering ESS to export reactive power Increase in windfarm output resulting in voltage increase High Voltage event caused by windfarm output triggering ESS to import reactive power DEADBANDDEADBAND 11.07 10.85

5.  2012. UK Power Networks. All rights reserved Operation: STATCOM Settings Change - July 2012 BEFORE SETTING CHANGES 10.96kV ± 0.11kV AFTER SETTING CHANGES 10.96kV ± 0.08kV Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Week 7 Week 8 Tightened under and over voltage targets from 10.96kV ± 0.11kV, to ±0.08kV kVAr exchanged with the network (Number of occurrences) / Voltage band

6.  2012. UK Power Networks. All rights reserved Operation: Real Power Exchanges - May 2012 Increase in demand due to switching from Export to Import Demand increase due to evening peak Drop in demand due to export from ESS Fluctuations due to Windfarm output or variation in demand

7.  2012. UK Power Networks. All rights reserved Li-ION BATTERIES SVC Light POWER CONVERSI ON SYSTEM (DC to AC) 1MVA STEP UP TRANSFORMER (2.2kV to 11kV) AND CIRCUIT BREAKER AUXILIARIES Considerations: Round Trip Efficiency and Losses The overall round trip efficiency of the installation is quoted to be more than 90% Several components will impact the efficiency and losses 50kW discharge scenario: 49.7 kW delivered by batteries 48 kW delivered to network Each component is being assessed individually 49.7 kW 48 kW

8.  2012. UK Power Networks. All rights reserved Considerations: Energy cost and Battery life On the current Hemsby tariff Energy import charges will be higher than the revenue that can be generated from exporting a similar amount of energy Battery life will depend on: Number of cycles Depth of discharges 1 x daily cycle @ 80% depth of discharge: 10 years 1 x daily cycle @ 40% depth of discharge: 20 years The impact of each mode of operation on the battery life will be considered Hemsby import charge Export revenue (80% System Sell price) Optimised Worst case 80% / 3,000 Cycles 40% / 10,000 Cycles

9.  2012. UK Power Networks. All rights reserved Management of Peak power flows Management of voltages across feeders Reduce reverse power flows Improve Power factor Management of Peak power flows Management of voltages across feeders Reduce reverse power flows Improve Power factor Switching between feeders Next steps: Device Operations Control mode 2: On-site Manual Control mode 3: Remote operations Management of peak power flows – Time of day Voltage stabilisation Voltage stabilisation (different set points) July 12 May 12 Jan 13 Oct 13 Benefit demonstration started Control mode 1: No intervention Control mode 4: Algorithmic control based on real time network measurements and wind farm output Now Benefit to be demonstrated Apr 11 Combine Voltage stabilisation + Real power exchanges

10.  2012. UK Power Networks. All rights reserved Conclusions: The storage device is performing as expected: Reduce voltage fluctuations and manage power flows The early stages of the project have been challenging: Energy contract, IT connections, troubleshooting issues following commissioning. Submitted request for extension: October 2013 More work is to be done but there is learning to be shared: Early learning report published. Copies available at the UK Power Networks stand