Transmission Response toTransmission Response to 2011 Floods and Cyclones

Outline of PresentationOutline of Presentation

S l f Q l d 2011 t l di t• Scale of Queensland 2011 natural disasters

• Queensland FloodsQueensland Floods

• Cyclones Anthony and Yasi

• Some Learnings

Scale and Impacts of DisastersScale and Impacts of Disasters

• Worst floods for more than a century• Worst floods for more than a century

• One of largest and intense cyclones ever experienced in FNQ

• 99% of Queensland was disaster activated

• >9,000kms of state roads were affected

• >29% of Queensland’s rail network impacted• >29% of Queensland s rail network impacted

• 480,000 homes and businesses without power

• Reconstruction cost of around $6,000 million

Impacts on Power SystemImpacts on Power System • Ergon and Energex distribution network seriously damaged• Ergon and Energex distribution network seriously damaged

• Threats to power stations and fuel supplies – but no damage

• Transmission network performed well:100% f id d t t i ff ild t– 100% of grid exposed to extreme rain, runoff, wild storms

– 10% - 20% of assets exposed to cyclones or flooding– Only 0.03% of assets seriously damaged– 99.99% of bulk electricity supplies maintained in the period

El t i it k t OK b t i d id i i• Electricity market OK but experienced wide price swings

Floods in Central and Southern QueenslandFloods in Central and Southern Queensland

CQ and SWQ Floods – Dec 2010CQ and SWQ Floods Dec 2010

• Record flooding of CQ and SWQ rivers and towns lasting weeks

• Severe flooding of mines, main roads, railway, cities and towns

• Impacted coal supplies (for months) and many power stations• Impacted coal supplies (for months) and many power stations

• Some 60 transmission towers inundated

• Threats to grid included electrical clearances, tower erosion, l d li fl d d b i b ild d t b i t tilandslips, flood debris build-up around tower bases, interruption to substation auxiliary power supplies, flooded access

Responses to CQ/SWQ FloodsResponses to CQ/SWQ Floods

• Temporary emergency generators at substations and refuelled daily using helicopters for access if necessary

• Aerial patrols using helicopters (or plane) to monitor flooded transmission lines – checking electrical clearances, easement

d i fl d d b i b ildand erosion, flood debris build-up

• SES and Ergon field staff regularly removed flood debris build-SES and Ergon field staff regularly removed flood debris buildup around the bases of towers by boat

• Rockhampton council repaired river bank erosion threatening one transmission tower

SEQ FloodsSEQ Floods

• Torrential SEQ rain caused flash flooding (loss of life) and flooding of Brisbane river

• SEQ Dams experienced record inflows, and released huge amounts of temporarily stored flood waters

• Heavy run-off caused land-slips and tower erosion that collapsed and threatened transmission towerscollapsed and threatened transmission towers

• Brisbane river flooding inundated one main substation and seriously threatened two transmission lines

275kV Tower collapse275kV Tower collapse

• Landslip collapsed one 275kv transmission tower• Landslip collapsed one 275kv transmission tower

• Access difficult as highway closed from landslips and local g y ptracks impassable due to boggy conditions

A permanent ‘H’ frame concrete pole str ct re as installed in• A permanent ‘H’ frame concrete pole structure was installed in two weeks

• No interruption to high voltage supply, but contributed to NEM constraints that saw extreme variations in pool prices

Landslips Undermining TowersLandslips Undermining Towers

L d li d t h ff th t d b f t i i• Landslips due to heavy run-off threatened a number of transmission towers

• Aerial patrols undertaken to indentify and monitor all lines

• Required temporary stabilising to manage risk of tower collapse• Required temporary stabilising to manage risk of tower collapse

• Installed series of cable stays anchored to large excavators and th t k hthen to rock anchors

• Permanent repairs to be undertaken laterp

• The transmission line remained in service throughout the event

River Bank Erosion - 275kV poleRiver Bank Erosion 275kV pole

• Brisbane river flooding severely eroded the riverbank near a 275kV• Brisbane river flooding severely eroded the riverbank near a 275kV steel transmission pole

30 t f i b k d d b k t th t t ’ b d• 30 metres of riverbank was eroded back to the structure’s base and up to a depth up to 13 metres

• Powerlink and Water Police monitored the condition during the flooding

• The two 275kV circuits were taken out of service, and contingency plans implement to erect a temporary line diversion across the flooded river

• This did not result in a loss of supply as the load was lower due to the effects of the flooding

Rocklea Substation InundatedRocklea Substation Inundated• 275/110kV substation supplying CBD and inner south-western pp y g

suburbs – built above the 1:100 year flood levels

• Flood waters reached a depth of about 1 metre in the substationFlood waters reached a depth of about 1 metre in the substation yard (not a material problem) and 400mm in the control building

C ti l i l t d t• Contingency plans were implemented to: – Remove the electronic equipment in the control room– Re-configure the substation and surrounding network to allow

t th h th b t ti t i t i l i thpower to pass through the substation to maintain supply in the area

• Other than a 3 hour interruption to enable the reconfiguration to be done safely, bulk electricity supply was maintained to some 70,000 customers throughout the ongoing flooding and recovery

Rocklea Substation RestorationRocklea Substation Restoration

O th fl d t d d th b t ti i t d• Once the flood waters receded, the substation was inspected, any flooded components were cleaned and checked

• Protection and control equipment and associated systems were reinstalled and checked, and the substation was returned to its original configurationoriginal configuration

• The transmission lines supplied by Rocklea substation were progressively energised and returned to the original configuration within 6 days of the flooding

• Other than the 3 hour interruption, there were no interruptions to bulk electricity supplies due to the Rocklea substation flooding.

Tennyson SubstationTennyson Substation

• Rebuilt well above the flood levels in 1998

• Continued to receive power via Rockleapower via Rocklea substation supplying 70,000 customers

Bundamba SubstationBundamba Substation• The 110kV transmission

line supplying Bundamba substation was de-energised forwas de energised for public safety resulting in an 8MW loss of supply for 24 hoursfor 24 hours

Tropical Cyclone AnthonyTropical Cyclone Anthony

• Category 2, TC Anthony crossed the coast near Bowen on the 30 January 2011

• A wind gust of 128 km/hr was recorded at Hamilton Island

• 1 metre storm surge was observed

Th d t P li k t f TC A th• There was no damage to Powerlink assets from TC Anthony

• Powerlink was more concerned about the severe cyclonePowerlink was more concerned about the severe cyclone already being monitored and following in its wake - Yasi

Tropical Cyclone YasiTropical Cyclone Yasi

• Category 5 – crossed coast 3 February near Tully

Tropical Cyclone YasiTropical Cyclone Yasi

• Category 5 cyclone – one of most powerful on Qld’s records

• Wind gusts up to 285km/hWind gusts up to 285km/h

• 90% of buildings in Tully, Mission Beach and El Arish were extensively damaged by winds and the storm surgeextensively damaged by winds and the storm surge

• Over 180,000 homes without power

• Gale force winds from Cairns to Townsville damagethe distribution network

• Total damage bill exceeded A$3 billion

Powerlink Response to Cyclone Yasip y

Cyclone damage to transmission network• 29 high voltage faults• Twelve 132kV circuits forced out – 400kms• Lost bulk supply to four 132kV substations • Two 132kV towers collapsed 8 leaning• Two 132kV towers collapsed, 8 leaning• Snapped earthwire, trees on lines, etc

ResponseResponse • Contingency plans implemented prior to Yasi• Access very difficult – wind, clouds, flooding• 9 circuits and 2 substations restored in 3 days• Towers replaced and all supply back in 6 days

Customer impacts • Minimal as Ergon distribution network

already badly damaged and out of service

Storm surge concernsStorm surge concerns

• Councils and EMQ issued storm surge warnings – predicting surges up to 7m

• Based on known information PLQ decided to de-energise:– Townsville East substation on the waterfront in Townsville – The Woree SVC in Cairns near Trinity Inlet

• Neither of these planned outages caused loss of supply• Neither of these planned outages caused loss of supply

• No storm surge issues were encountered at these two sites or gany other PLQ assets

State Disaster Co-ordinationState Disaster Co ordination • Powerlink is a member of the State Disaster Co-ordinationPowerlink is a member of the State Disaster Co ordination

Committee (SDGG)

• Daily SDCG briefings with BOM/hydrologists updates etc• Daily SDCG briefings with BOM/hydrologists updates etc

• This two level involvement proved advantageous to PLQ

• Access to ADF resources: – Navy Sea King Helicopter– Blackhawk Helicopters– P3 Orion Rapid Damage Assessment aerial photography

• Access to SES Flood Boats

• Access to Water Police BoatAccess to Water Police Boat

Some LearningsSome Learnings• Established forward command post at Cairns which liaised with• Established forward command post at Cairns which liaised with

the front line and with the CEMT in Brisbane

• Chief Operating Officer and Communications Manager managed media and local stakeholders from Townsville base (local Mayors, District Disaster Co-ordinator, Ergon, etc)( y , , g , )

• Pre-positioned helicopters, emergency structures, field crews d i t t id f th dand equipment outside of the danger area

• Most technical expertise located in Brisbane with someMost technical expertise located in Brisbane with some engineers positioned locally for damage inspections

Learnings continuedLearnings continued

C i ti bil h i ll f il ithi• Communications - mobile phone services usually fail within hours of wide-scale power supply interruptions. Telstra and Optus tried to respond - but satellite phones needed

• Even in Townsville - no power, water or food in first days

• Value of bog mats - we had access to over 700 bog mats

• Accommodation became a major issue for response agencies

• Priority lane for electricity vehicles on highways into FNQ

Command and ControlCommand and Control

• Powerlink managed these events using its normal emergency management process, which includes interaction with the distribution entities (Energex Ergon Energy); and withdistribution entities (Energex, Ergon Energy); and with emergency authorities (SDCC, EMQ, etc).

• For the SEQ floods and Cyclone Yasi, Powerlink’s Corporate Emergency Management Team was convened for approximately 10 and 6 days respectivelypp y y p y

• Level 3 Emergencies were declared for both events

Discussions and QuestionsDiscussions and Questions