1. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 The introduction of local system services – the case of storage in the low voltage network Yoush van Vlimmeren, University of Technology Eindhoven ; Greet M.A. Vanalme, University of Technology Eindhoven ; Geert P.J. Verbong, University of Technology Eindhoven; Martijn Bongaerts, Alliander; Wil L. Kling, University of Technology Eindhoven

2. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Contents Introduction Local system services Fitting local system services in the market Case study: local system services using locally available storage Conclusions

3. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Introduction Socio-economic trends Renewable energy sources ↑ New loads: E-cars, heat pumps Challenges electricity system Unbalance ↑ Local congestion ↑ Research topic: Local system services (LSS) LSS use locally available flexibility (e.g.  CHP, flexible load, storage,…) Problem definition  Current system services might become insufficient

4. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Local system services Local for localLocal for global Voltage control Network alleviation Island or micro grid operation Right-through capability Local balance control Provide unbalance power Reduce installed generation capacity Reduce network losses Improve network efficiency Contribute to global balance control  Local for local: location of LSS supplying devices important  Local for global: need of large number of devices + effective control

5. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Fitting LSS in the market ActorPossible impact of LSS ConsumerCheaper energy in exchange of flexibility, privacy issues TSOMore complexity DNOMay offer additional services (DNO → DSO) BRPLocal balance control might assist global balance SupplierAs contact to consumer: new contracts RegulatorNew legislation Service company May offer services (buying/ selling energy, selling flexibility, …)

6. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Fitting LSS in the market - barriers Technical challenges Effective, reliable and secured control & communication Legislation Requirements for suppliers of system services (minimum 5 MW unbalance power, 100% availability, direct control by TSO, registration and bidding needed at TSO level) Tariff structure DSO Established routines Main actors have no direct need for LSS …

7. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage Introduction LSS in residential area, local congestion management + balance keeping Using storage (+) promising new technology, with little intrusion in consumer’s comfort (-) expensive  strategies where storage can address several markets / fulfil several system services are studied Simulations for 3 configurations Electric heat pump + E-car for each house E-car + PV for each house  CHP, electric heat pump, E-car and PV for 50% of houses

8. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage Place storage Control level Control strategy Simulation name Every house Residential Difference in tariffs: day-night, feed-in –extraction,… (none) Household responds on signal sent by integrating party if beneficial. Houses, price Every house CentralAPX driven (none) Service driven Houses, direct SubstationCentralDSO control Central, direct SubstationCentralCommercial controlCentral, price Control strategies of storage in residential area

9. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage Simulations: Control of storage device

10. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage eHP + E-carE- car + PVMixture No control1030 hours17 hours0 hours Houses, direct650 hours0 hours Houses, price630 hours7 hours0 hours Central, direct930 hours26 hours0 hours Central, price930 hours9 hours0 hours Yearly transformer overloading (hours) Simulation results Beneficial effects on transformer loading Distribution networks with a high degree of utilisation (e.g. eHP+ E-car) less suitable for providing LSS

11. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage Simulation results: transformer loading Direct control Reaction of storage on unbalance signal  extra peaks in transformer loading Price signals induce peak shaving Price based control

12. Frankfurt (Germany), 6-9 June 2011 Simulation results: summary Beneficial effects on transformer loading, voltages and losses within LV network Distribution networks with a high degree of utilisation (e.g. eHP+ E-car) are less suitable for providing LSS Possible transformer overloading due to unbalance signal  solution: prioritize congestion signal Price signals induce peak shaving Interference between market and congestion signals reduces the responsiveness of the storage units Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage

13. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Case study: LSS using storage Institutional embedding – actor tasks and responsibilities ControlConsumerDNOBRPRegulator Houses, direct - Own storage - Allow control - Send network signal - Measure response Send BRP signal Allow tariff change Houses, price - Own storage - Set price threshold Central, direct (none) Own storage Send BRP signal Allow storage ownership by DNO Central, price (none) Send congestion signal Own storage (none)

14. Frankfurt (Germany), 6-9 June 2011 Greet Vanalme – NL – RIF Session 6 – Paper 0786 Conclusions LSS for “for local” (network alleviation, voltage control,…): suitable but No incentive for DSO Adaptation of tariff system needed Storage expensive LSS for “for global” (access to high value markets): more barriers More complex control scheme needed More legislative barriers Actors have no need to implement