2. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Wind Energy Penetration in Islands: Limitations and Prospects N. Hatziargyriou S. Papathanassiou, T. Chaviaropoulos, I. Tsipouridis NTUA CRES PPC

3. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Island Systems

4. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Installed Wind Power (ΜW) Small Hydro (MW) Biomass (MW) PV (kW) Hellenic Interconnected system 3416120.6105 Crete870.60.4442 Cyclades5.400182 Dodecanesse9.90037.5 Rest Aegean Islands 26.10073 Total islands128.40.60.4735 Total469.461.621840 RES in Greece (1)

5. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens With authorization Wind Power (ΜW) Small Hydro (MW) Biomass+ Geothermal (MW) PV (kW) Hellenic Interconnected system 3039.4348.5940.5760 Crete132.300650 Cyclades33.25000 Dodecanesse68.500.50 Rest Aegean Islands17.153.88100 Total islands251.2352.398.5750 Total3290.6352.39491510 RES in Greece (2)

6. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens –Small isolated Power system –2MW. –11% Annual RES penetration –Wind & PV –Up to 100% instantaneous RES Penetration Kythnos Island

7. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Kythnos Power System-today

8. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Crete Island Largest isolated power system in Greece 3 Power Stations (Chania,Linoperamata,Atherinolakos)- 26 thermal units, Peak 540 MW(2004), 87.1MW Wind capacity-Wind power penetration 10%

9. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Crete System Single-Line Diagram

10. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens W/F Production 1993-2000 [KWh]

11. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Penetration during the day of max. inst. output ( Dec.28.2000)

12. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Rokas W/F output (13 May 1998)

13. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Rokas W/F output ( 20 May 1998 )

14. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Frequency and production due to Gas Turbine Outage

15. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Summary of Experience from Wind Power Penetration in Crete High efficiencies (Capacity Factor in 2000:37,33%) l Stable output but with serious exceptions l Normal Voltage fluctuation at connecting W/F bus l Higher yields during summer months but lower,or zero, at evening peaks l No problem for Flicker or Harmonics l Economical considerations.

16. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Large Scale Penetration of Increased Wind Power in Island Systems Wind Power - Intermittent Power Source Wind Power – partly non-controllable Effects → Operation with increased uncertainty, requirements for reliable short-term forecasts of renewable source production. → Effects on power system security both steady-state and dynamic, inability of conventional directly coupled Wind Turbines to provide ancillary services, requirements for on-line security assessment. → Effects on economic operation → Power Quality ???

17. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Fault Ride-Through Capability Modern WG are required to remain connected during a fault Various standards for voltage dips to be sustained Frequency Requirements?

18. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens CARE&MORE CARE EC Projects: Advanced Control Advice for Power Systems with Large-Scale Integration of RES JOULE JOR3-CT96-0119 & ENERGIE ERK5-CT1999-00019 Minimise production costs through unit commitment and on- line economic dispatch of both conventional and RES also considering market and increased security. Provide short-term forecasts of load and wind for short-term (0-8 hr) and medium-term horizon (4-48 hrs). Maximise power system security by on-line security assessment modules, that supervise scheduling of the power units and monitor the system security margin. Also provide corrective control actions.

19. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens The CARE System Architecture

20. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Execution Cycles of MORE CARE For Crete H=48 hrs, h=4 hrs, t1=1 hr, t2=20 min

21. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Current System Operation and Economic Dispatch Wind Parks Loads Current Production Economic Dispatch

22. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Off-line execution of Economic Scheduling functions assuming: –Spinning Reserve at least equal to wind power – no wind power forecasting –Spinning reserve at least equal to 50% of wind power – 50% maximum forecasting error –Spinning reserve at least equal to 20% of wind power to face very short wind fluctuations – very advanced WF with 20% maximum forecasting error. –Evaluation of economic impacts Economic Appraisal of Wind Power Forecasting

23. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens More accurate wind power forecasting reduces operating costs as follows: Monthly cost savings with thermal spinning reserve equal to 50% of wind power 1.8-3.5% (163-480 kEuro) Monthly cost savings with thermal spinning reserve equal to 20% of wind power 2.3-5.3% (217-758 kEuro) Economic Appraisal of Wind Power Forecasting - Results

24. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Unit Commitment Average gain 3.1% Economic Dispatch Average gain 1.7% Economic Scheduling Evaluation

25. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Relative gain provided by GA Economic Scheduling Functions Economic Scheduling Evaluation

26. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Actual OperationProposed Operation Dynamic Security Evaluation

27. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Short term flicker (Pst) at W/P bus of Sitia S/S ( 12 Aug. 1998 )

28. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Long term flicker (Plt) at W/F bus of Sitia S/S ( 12 aug. 1998 )

29. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens PROJECT: Integration of Wind Turbines into Electricity Supply Networks with Limited Power Transportation Capacity –Wiring (JOR3-CT98-0245) Electrical network of the Greek island Samos VESTAS WINDMATIC NEG MICON

30. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Frequency behaviour of the island grid of Samos during one week

31. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Diesel generator production during 13 days

32. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens The measurement campaign gave some unexpected results:  Most important is the fact that the voltages are highly distorted in the flicker producing frequency region, due to firing harmonics of the power station diesel engines. This background distortion is large enough to completely mask the effect of the flicker emitted by the WTs. The connection of the WTs leaves more or less unaffected the overall flicker levels, and in certain cases even reduces them.  The effect of the Vestas wind turbines on the frequency spectrum of voltage and power at the diesel power station was investigated. The same spectrum of voltages occurs with and without the wind turbines.

33. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens Voltage PSD before cut-in of WTs Voltage PSD after cut-in of WTs Firing of diesel engines

34. European Wind Energy Conference & Exhibition, EWEC2006, 27 Febr-2 March 2006, Athens CONCLUSIONS  Wind power installations in islands provide economical benefits compared to diesel  Increased requirements for robust Wind Turbines equipped with Low Voltage Ride Through capabilities and able to withstand frequency varaitions  Need for advanced control systems to deal with optimal operation and management of power systems with large integration from wind power.  Application of the MORE CARE control software on Crete has shown clear economic gains and timely warning for more secure operation.  Flicker levels do not seem to be affected by the operation of WTs.