Integration of Large-Scale RES in Island Power Systems Prof. Nikos Hatziargyriou,

1. Integration of Large-Scale RES in Island Power Systems Prof. Nikos Hatziargyriou, National Technical University of Athens nh@power.ece.ntua.gr

2. Outline • RES in Greek Islands • The Power System of Crete • Smart Grids for the Greek Islands • More Care Energy Management System • Microgrids • The Kythnos Experiment

3. Power Stations on Greek Non Interconnected Islands

4. 480 470 RES Production per system in 2010 15,8 % 7,4 % 10,1 % 13,9 % 8,5 % 13,6 % 8,2% 11,4 % 7,9 % 13,5 % 3,4 % 9,8 % 4,6 % 0,9 %

5. Average Variable Cost per system (2010) Very Small Islands New Power Stations & and Large islands AVC SMP Crete Mykonos

6. Significant increase of RES installationin Greek islands based on new technologies Power Stations • Hybrid Power Stations with Wind Farms, pump-storage systems and Hydroelectric Power Stations • Nominal capacity from 2 MW up to 75 MW • Concentrated Solar Power (CSP) Stations with storage systems of thermal energy from 4h up to 8h • Nominal capacity from 25 MW up to 70 MW • Hybrid Power Stations with battery systems and Wind Farms or Sterling Generator.

7. Total RES installed capacity and productionin Greek Non Interconnected Islands for 2003-2020 40 % 28,2% 12,1% 2015 (MW) W/F 428 PV 190 HPS50 CSP 35 2018 (MW) W/F 517 PV 220 HPS153 CSP 105

8. Power system of Crete

9. Base-load mainly supplied by steam and diesel units. Combustion turbine units normally supply daily peak load at high running cost. 26 Wind farms of total Capacity 166 MW. Most of Wind Farms installed at the eastern part of the island. PVs 60 MW Crete – Operational CharacteristicsLargest Island System in Greece with highest rate of energy and demand increase. Three thermal power plants, installed cap. 800 MW.

10. EES-UETP “Planning, Designing and Operating the Distribution Network for Exploitation of DER”, Cagliari, 27-30/9/04

11. EES-UETP “Planning, Designing and Operating the Distribution Network for Exploitation of DER”, Cagliari, 27-30/9/04

12. EES-UETP “Planning, Designing and Operating the Distribution Network for Exploitation of DER”, Cagliari, 27-30/9/04

13. Wind Park in Crete

14. Load and Wind Farm production in Crete system during the year 2010 640MW =3.7 170MW

15. Rokas W/F output (13 May 1998)

16. Rokas W/F output ( 20 May 1998 )

17. Development of Hybrid Power Stations with pumping systems and CSP Power Stations in Crete up to 2018 HPS 12MW HPS WF (28.9/11.9 MW) HPS 75 MW HPS1.95MW CSP 50MW CSP 70MW HPS 5.1 MW Hybrid 9MW CSP 60MW HPS 5MW HPS9MW HPS WF (39.95/9.35 MW) HPS5.1MW CSP 25MW HPS 12MW CSP 38MW HPS 15MW HPS 1.95MW

18. System Operation (27/6/2011) (PV ~35MW) High RES penetration (>30%) Technical minimum problem Expensive unit used

19. Increased WF penetration PV production is estimated. RES penetration>50%

20. Wind Production the day of year’s load peak (Aug.12.1999)

21. Voltage and frequency • Operating frequency bandwidth: 49,9 - 50,1 Hz (Normal mode) 49,3 - 50,5 Hz (Contingency mode) • Operating voltage bandwidth: + 3,5 % • Typical power reserve margins: 10% (spinning)

22. Operational problems • Technical limits of thermal base-load plant during valleys of load demand • Narrow tolerances of wind generators to voltage and frequency deviations • Loss of wind generation following incidents of system faults or system transients

23. Operational problems (continued) • Wind availability, and short-term wind variations (gusts) – the latter resulting in substantial power swings in wind generation outputs • Communication problems between the system Control Center and the Wind farms • Miscellaneous, such as: wind-generator maintenance and repairs, distribution line problems, etc

24. MORE CARE

25. Major functionalities of MORE CARE • Forecasting Modules • Unit Commitment/Economic Dispatch • RES/Storage Management • Optimal Power Flow • Security Monitoring/Assessment

26. The CARE System Architecture

27. Flow-chart

28. MMI of More Care System

29. MMI for Wind Forecast

30. Load & Wind Forecasting • Modern Systems Provide Advanced Capabilities • For Wind Power forecasting: • ICCS participates in innovative projects: Anemos.plus and SafeWind • The information includes confidence intervals and extreme events Meteo Forecast Advanced Modules

31. Unit Commitment /Economic Dispatch The Unit Commitment problem becomes very complex: • Market Rules and Existing Contracts • RES Management • Future Storage Management • Ancillary Services according to market rules • Technical Constraints and Reserve Management

32. Unit Commitment /Economic Dispatch • Advanced functionalities to provide advice to the operators Simple Messages to the operator Advanced Modules

33. Security Monitoring/Assessment • Operation of islands becomes very complex • It is very demanding for the operator to consider power flow constraints or dynamic response of generators • Early Warning to the operators in case of security concerns is necessary – AI techniques Dynamic Monitoring & OPF

34. Simulation of 23 MW Gas Turbine Outage Case 1. Load of 207.2 MW, Wind Power 69 MW, 33.3% penetration Case 2. Load of 199 MW, Wind Power 55.73 MW, 28% penetration

35. Historical Data Management • Online History Access

36. Statistics and Reporting

37. Conclusions • Increased RES penetration complicates islands operation • In Crete, the largest Greek island, RES annual energy penetration reaches 20%, hourly penetration might exceed 50%. • For secure and economical operation with increased RES penetration advanced EMS are required • MORE CARE provides advanced forecasting, scheduling and security warning functionalities.

38. Thank you!