Hawke s Bay Snow Event

Transcription

1 Hawke s Bay Snow Event 6 August National Lifelines Forum 2 November 2016 Brendan Olsen, Regional Service Manager Lower North Island

2 Weather forecast

3 Map

4 Normal grid configuration before event Core grid Wairakei 70MW 70MW G Whirinaki Redclyffe 220kV Whakatu Fernhill X Waipawa Redclyffe 110kV Tuai 40MW G

5 Saturday 6 th August First Tripping at 2:30am (RDF_WRK_1), several reclosed attempts but remained out. Loss to Hawkes Bay at 2:45am 209MW all restored at 4:48am (133 minutes) Service Providers called to patrol line Second loss at 9:59am 207MW all restored at 11:34am (95 minutes) Remaining 220kV circuit restored 12:13pm

6 Customers affected by event

7 Genesis Energy s assets affected by event

8 Contact Energy s assets affected by event

9 Pan Pac s assets in affected by event

10 Event Management Both National Grid Operating Centres (Auckland & Christchurch) managed with National Co-ordinations Centres Hamilton & Wellington). Event rooms stood up (Operations, Maintenance, Engineering) with Skype for those contributing from home on Saturday at 8am. HB Civil Defence contacted during both losses of supply, Teleconference 3pm with s updates subsequent days. Media kept update along with social media (facebook) Continued during the day with handovers until 8pm then stood down. Reviewed 10am Sunday then stood down

11 Faults locations

12 Aerial patrol

13 Patrol findings

14 Phase-to-phase faults Distance to Fault Towers Distance to Fault Towers Faults Found from Patrols Span Yellow Phase rolled over Faults Found from Patrols Span Red Phase Twist Span Red Phase Twist Span Red & Blue Phase rolled over Span Blue Phase rolled over Distance between phases 5.5m

15 Recovery Further Helicopter Patrol and ground visits to access site access. WRK_WHI_1 outage September to flip conductors, check spacers while reinsulation being undertaken. RDF_WRK_1 outage October to flip conductors, check spacers while reinsulation being undertaken.

16 Post Event 19 of 20 Actions identified 8 August completed Hawkes Bay 220kV Contingency plan updated Equipment issues (4 separate) Loss of Metservice Weather Station Operations visit to Unison and Pan Pac

17 Longer term Investigations Electrical Islanding for Hawkes Bay Upgrade 220kV Protection (reduce the potential for lines tripping) Conduct further review on 110kV Contingency Plan Following Transpower protection analysis, direct-connect and lines customers review their protection Hawkes Bay restoration automation design Investigate whether a case to install interphase spacers is feasible Determine if Transpower should procure black start capability for the region (at Tuai)

18 Learnings Weather events are becoming more frequent and severe 1 every 3-4 years for Hawkes Bay. All parties have a particular role to play in providing resilience for the Hawkes Bay. Be aware of each others resilience-related capabilities and abilities. Contingency plans are important ensure you review and share them. Risk Analysis Preventative Controls pre-event, Impact Minimisation Controls during the event.

19

20 Impact on Unison Network Power lost at 6:40am. 200 connections lost off Hawkes Bay Network. 190 connections lost off Taupo Network suffered significant damage multiple generators including network generators deployed. HB Restoration: 100 within 3-4 days, 7 days remaining 100. Taupo Restoration: 80 within 10 days, 25 days, remaining 20 at 4 weeks final connections 2/3 September. 70 staff in the field working to restore the network.

21 Taupo Network

22 Unison Key Learnings Lifelines relationships and processes important Inter-agency co-ordination was important Availability of power closely linked to welfare Animal welfare important Proactive public communication Overall effective response and co-ordination working closely with Lifelines and Civil Defence