Integration of Large-Scale RES in Island Power Systems Prof. Nikos Hatziargyriou, National Technical University of Athens

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

Power Stations on Greek Non Interconnected Islands 3 6 Thermal Stations Total installed capacity MW Capacity of new thermal units ( 2011 – 2015 ) RES Stations 80 Wind Farms 883 PVs Capacity of new RES stations ( 2011 – 2015) Wind Farms PVs Hybrid Stations CSP Stations

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

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

Significant increase of RES installation in 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.

Total RES installed capacity and production in Greek Non Interconnected Islands for ,1% 28,2% 40 % 2015(MW) W/F428 PV190 HPS50 CSP (MW) W/F517 PV220 HPS153 CSP105

Power system of Crete

Crete – Operational Characteristics Largest Island System in Greece with highest rate of energy and demand increase. Three thermal power plants, installed cap. 800 MW.  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 No. of Machines Nominal Power (MW) Linoperamata Steam6110 Diesel448 Gas5120 Chania Gas6198 CC Atherinolakos Steam Diesel

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

Wind Park in Crete

Load and Wind Farm production in Crete system during the year MW 170MW =3.7

Rokas W/F output (13 May 1998)

Rokas W/F output ( 20 May 1998 )

HPS WF (28.9/11.9 MW) HPS 5MW HPS 5.1MW HPS WF (39.95/9.35 MW) HPS 75 MW HPS 5.1 MW Hybrid 9MW Development of Hybrid Power Stations with pumping systems and CSP Power Stations in Crete up to 2018 HPS 12MW CSP 25MW CSP 70MW HPS 1.95MW HPS 12MW HPS 9MW HPS 15MW HPS 1.95MW CSP 50MW POWER STATION TYPE (total capacity)STATIONSNOMINAL CAPACITY Hybrid Power Station (151,1 MW)12 – 75 MW Concentrated Solar Power (243 MW)525 – 70 MW CSP 38MW CSP 60MW

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

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

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

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)

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

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

MORE CARE

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

The CARE System Architecture

Flow- chart

MMI of More Care System

MMI for Wind Forecast

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 Advanced Modules Meteo Forecast

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

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

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

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

Historical Data Management  Online History Access

Statistics and Reporting

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.

Thank you!