Aspects of Relevance in Offshore Wind Farm Reliability Assessment

1. 2nd PhD Seminar on Wind Energy in Europe Risø National Laboratory, 4-5 October 2006 Aspects of Relevance in Offshore Wind Farm Reliability Assessment Nicola Barberis Negra nibne@dongenergy.dk

2. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk

3. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk

4. Introduction - Definition • What is Reliability? • “Overall ability of the system to perform its function adequately, for the period of time considered, under the operation conditions intended” • Reliability in Power System • Operation • Planning Nicola Barberis Negra - nibne@dongenergy.dk

5. Generation facilities Hierarchical Level I (HLI) Generating Units and Load Transmission facilities Hierarchical Level II (HLII) HLI + Transmission System Hierarchical Level III (HLIII) Distribution facilities HLII + Distribution System Introduction – Structure of Reliability Nicola Barberis Negra - nibne@dongenergy.dk

6. Generation facilities Hierarchical Level I (HLI) Generating Units and Load Transmission facilities Hierarchical Level II (HLII) HLI + Transmission System Hierarchical Level III (HLIII) Distribution facilities HLII + Distribution System Introduction – Structure of Reliability Two new aspects • Distributed Generation • Private Suppliers Nicola Barberis Negra - nibne@dongenergy.dk

7. Introduction – Evaluation Methods • Deterministic solutions • First used approaches • No uncertainty can be included • Probabilistic methods • Analytical models or simulations • Uncertainty may be included • Broad range of studies Nicola Barberis Negra - nibne@dongenergy.dk

8. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk

9. Why Wind Energy • New structure of power systems • Increase of installed capacity (e.g. Germany) • Increase of wind energy penetration (e.g. Denmark) • Evolution of Installations • Onshore installations (smaller and distributed) • Offshore installations (larger and concentrated) Nicola Barberis Negra - nibne@dongenergy.dk

10. Why Wind Energy - Aspects of Relevance • Simulation of wind speed (WS) • Wake effects • Wind turbine technology • Offshore environment • Different wind speed in the installation site • Power collection grid in the wind park • Correlation of output power for different wind farms • Grid connection configuration • Hub height variations Nicola Barberis Negra - nibne@dongenergy.dk

11. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk

12. Example – Monte Carlo Simulation “Estimation of a-posteriori reliability indices by simulating the actual random behaviour of the system for the period intended” • Main steps: • Simulation and system definition • Components availability in each sample • Synthetic Wind speed time series in each sample • Wind farm output power in each sample • Wind farm index evaluation Nicola Barberis Negra - nibne@dongenergy.dk

13. Example – Simulation Definition Sequential Monte Carlo simulation • Period of 1 year with hourly step (8760 hours) • Relevant aspects included • Random wind speed time series • Wind turbine technology • Power collection grid in the wind park • Grid connection configuration • Offshore environment Nicola Barberis Negra - nibne@dongenergy.dk

14. Example – System Definition Wind farm layout Component data Nicola Barberis Negra - nibne@dongenergy.dk

15. Example – Simulation Procedure 2. Component availability 4. Wind Farm output power 5. Wind Farm Indices 3. Wind speed time series Nicola Barberis Negra - nibne@dongenergy.dk

16. Example – Results • IWP =Installed Wind Power • IWE = Installed Wind Energy • EAWE = Expected Available Wind Energy • EGWEWTF = EAWE With WT Failure • EGWE = Expected Generated Wind Energy • CF = Capacity Factor • GR = Generation Ratio Nicola Barberis Negra - nibne@dongenergy.dk

17. Example – Comments • Different aspects of wind farm production • Relevance of including component failures (indices 3 to 5) • CF reasonable for offshore installations • Huge computational time • Possibility of plotting index distribution functions Nicola Barberis Negra - nibne@dongenergy.dk

18. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk

19. Conclusions • Relevance of including wind generation into power system reliability assessment • Importance of 9 aspects for the problem • Monte Carlo simulation is a powerful tool, but it needs some optimizations • Future developments • Inclusion of all missed aspects • Improvement of the simulation • HLI and HLII analysis Nicola Barberis Negra - nibne@dongenergy.dk

20. Outline • Introduction to Reliability • Why Wind Generation into Reliability • Example of Evaluation • Conclusions • Questions Nicola Barberis Negra - nibne@dongenergy.dk