Interchange Capacity between Portugal and Spain

1. 2ndInternational Conference on Electrical Engineering Coimbra, 28 November2007 Interchange Capacity between Portugal and Spain Methodology, Evolution and its use in the MIBEL environment Rui Pestana

2. Interchange Capacity between Portugal and Spain • Methodology • ETSO • REN & REE • Evolution • Structural (investments) • Not Structural (investigation) • Use • Yearly : 2001-2006 • Monthly : Jan-Nov 2007 • MIBEL (>1-Jul-2007)

3. Methodology – ETSO ETSO – European Transmission System Operator • TTC – Total Transfer Capacity • NTC – Net Transfer Capacity • NTC = TTC – TRM • TRM – Transmission Reliability Margin • AAC – Already Allocated Capacity • ATC – Available Transmission Capacity • ATC = NTC – AAC

4. Methodology – ETSO

5. Methodology – Limitations • Parallel Flows • It is not possible to define an NTC for all pairs of countries

6. Methodology – Limitations • Program versus Physical • The generation Shift is not equal to Physical flow change at the tie-lines • NTF – Notified Transmission Flow • TTF – Total Transfer Flow

7. Methodology – Computation • Generation Shift • Start with base case including some Import/Export flow • Increase Generation on system A • Limited by Generation Capacity • Decrease Generation on system B

8. Methodology – Computation • Export of Portugal • It maybe limit Generation capacity in Portugal • The hydro (run-of-river) is not mobilized • The renewable (wind) is also not mobilized

9. Methodology – Computation • Import from Spain • There is no limit in the Generation capacity, since we may import from France (in theory)

10. Methodology – Computation • Generation Shift • No load changes • TSO A computes • For Generation in A • It uses economic merit order (economical signal) • For Generation in B • It uses pro-rata order (no economical signal) • These differences may be justified because the limit from A to B computed by A is different from the computation by B. • In ETSO all TSO must provide reference save cases (winter and Summer) • Where all network elements are available (not realistic)

11. Methodology – ETSO • Summer and Winter NTC in Europe www.etso-net.org

12. Methodology – REN and REE • New procedure on the Iberian Methodology • Horizons • Time date to deliver data and results • Unavailability of network and generation • That influence the Interchange Capacity • More realistic than ETSO • Generation order merit • More realistic than ETSO

13. Methodology – REN and REE • New procedure on the Iberian Methodology • TRM - Transmission Reliability Margin 10% of the Capacity with a minimum of 100 MW • Covers errors on the network model used for the computation • Covers Load forecast errors • Covers Renewable Generation forecast errors • Network security rules for each TSO • Contingency analysis is also applied in foreign network • Each TSO checks its network limits • Overload in foreign network is ignored • Different results may show up !

14. Methodology – REN and REE • Horizons • Yearly • REN : Monthly discrimination (ERSE, Hydrology) • REE : Season discrimination • Trimester • Work day and weekend peak and off-peak discrimination • Monthly • Daily peak and off-peak discrimination • Weekly • For two weeks • Hourly discrimination

15. Methodology – REN and REE • Firmness (situation before MIBEL)

16. Methodology – REN and REE • PTR – Physical Transmission Rights • After the Capacity is given in the daily market, if there is a need to reduce the interchange capacity, the TSO uses “counter trading” to guarantee the Transmission Rights • Auction • “Use it or get paid for it”

17. 1 2 3 4 5 6 MIBEL : Market ( OMEL + OMIP/OMIClear ) + TSO ( REE + REN) • Capacity work flow

18. Interchange Capacity between Portugal and Spain • Methodology • ETSO • REN & REE • Evolution • Structural (investments) • Not Structural (investigations) • Use • Yearly : 2001-2006 • Monthly : Jan-Nov 2007 • MIBEL (>1-Jul-2007)

19. Evolution of the Tie Lines • Situation in 2002 • 2 x 400 kV • Alto Lindoso – Cartelle • Falagueira - Cedillo • 3 x 220 kV • Bemposta – Aldeadávila • Pocinho – Aldeadávila • Pocinho – Saucelle

20. Evolution of the Tie Lines • Work plan : 1st Phase (until 2008) • New tie lines • LALCTL • LAVBAL • Upgrade • Corridor on Tagus • Corridor on Douro

21. Evolution of the Tie Lines • Situation in 2006 • 4 x 400 kV • 2 x Alto Lindoso – Cartelle • Falagueira – Cedillo • Alqueva - Balboa • 3 x 220 kV • Bemposta – Aldeadávila • Pocinho – Aldeadávila • Pocinho – Saucelle

22. Evolution of the Tie Lines • Where the Energy Flows ? Monthly Net Flow in 2006 by tie lines (+) Portugal to Spain

23. Evolution of the Tie Lines 2x58% • Where the Energy Flows ? We have (±)43% of loop flows 7% 2x14% 17% 19%

24. Evolution of the Tie Lines • Upgrade in Douro corridor • New Substation at International Douro • Lagoaça : 400/220 kV • To avoid the loop flows • New 400 kV Line

25. Evolution of the Tie Lines • Uprating on Tagus corridor

26. Evolution of the Tie Lines • New tie lines • Algarve

27. Evolution of the Tie Lines • High Speed Rail • Requires 400 kV • Double phase load • Needs a very high short circuit current

28. Evolution of the Tie Lines • High Speed Rail • Porto – Vigo • Will increase Import Capacity • Populated region

29. Evolution of the Tie Lines • High Speed Rail • Évora – Badajoz

30. Evolution of the Tie Lines • Situation in 201? • 8 x 400 kV • 3 x 220 kV

31. When we solve the “bottleneck of the tie-lines” we get congestions on the internal lines Uprating From 50ºC to 75ºC From 50ºC to 85ºC From Bear to Zebra From Zebra to Zambeze Upgrade From 150 kV to 220 kV From 220 kV to 400 kV Evolution of the Network

32. Evolution of the Network • Uprating since 1999 2007 value is estimated We have uprated 35% of the lines

33. Investigation : Real Time Ratings Temperature of conductors • Thermal equilibrium

34. Real Time Ratings Temperature of conductors • Static values I – current – dynamic R – Solar Radiation – static = 1000 W/m2 Ta – Ambient Temperature – reference W – Wind speed – static = 0.6m/s = 2ft/s

35. Real Time Ratings R – Solar Radiation – dynamic Summer case : 12th July 2005 During Peak load the Solar radiation is 1000 W/m2

36. Real Time Ratings R – Solar Radiation – dynamic Winter case : 27th January 2005 During Peak load the Solar radiation is 0 W/m2

37. Real Time Ratings Weather Conditions – for off-line Studies • Ambient Temperature • After sunrise : Monthly reference temperature • Before sunrise : Monthly reference temperature minus 5ºC

38. Real Time Ratings Weather Conditions – for off-line Studies • Ambient Temperature • After sunrise : Monthly reference temperature • Before sunrise : Monthly reference temperature minus 5ºC • Solar Radiation • During day time : 1000 W/m2 • During night time : 0 W/m2

39. Real Time Ratings Weather Conditions – for off-line Studies • During the off-peak hours the price in the pool is lower and we trade more, so we need more capacity on the network (and it’s there)

40. Real Time Ratings Temperature of conductors • Dynamic values I – current – dynamic R – Solar Radiation – dynamic Ta – Ambient Temperature – dynamic W – Wind speed – static = 0.6m/s = 2ft/s

41. Real Time Ratings • CAT-1 pilot project • To validate the hypotheses

42. Real Time Ratings • CAT-1 Installation in 2004 • GSM uplink

43. Real Time Ratings • CAT-1 upgrade in 2005 • FO link to SCADA

44. Interchange Capacity between Portugal and Spain • Methodology • ETSO • REN & REE • Evolution • Structural (investments) • Not Structural (investigation) • Use • Yearly : 2001-2006 • Monthly : Jan-Nov 2007 • MIBEL (>1-Jul-2007)

45. Yearly results : REN and REE • They are not equal • The importing country tends to limit the flow • It is easier to export problems

46. Yearly results : REN and REE • In case of the exporting country is limiting the capacity, it is caused by generation capacity and not by network capacity • In theory there is no network restrictions

47. Monthly results : REN

48. Monthly results : REE

49. Weekly results : REN - Export

50. Weekly results : REN - Import