Recent blackouts in US/Canada and continental Europe: Is liberalisation to blame? Janusz W. Bialek University of Edinburgh, Scotland

The Oregonian, 24 August 2003, after C. Taylor

Recent major blackouts l 6 blackouts within 6 weeks affecting 112 million people in 5 countries l 14 August 2003, USA/Canada: max ~62 GW lost, ~50M people, restoration up to a few days l 28 August 2003, south London, 724 MW lost, 410k people + Tube & Rail at rush hour, restoration: 40 min. l 5 September 2003, east Birmingham, 250 MW lost, 220k people, restoration: 11 min. l 23 September 2003, Sweden and Denmark, 5M people, restoration 4 hours l 28 September 2003, whole Italy except Sardinia, 57M people, restoration: 4 hours. l Who’s next?

What’s important for people and policy makers? l Electricity prices l Environmental effect l Security of supply

Recent blackouts l All blackouts were transmission-based l No problem with generation adequacy l Systems were not stressed prior to blackouts l Two categories: –Cross-border trades: continental Europe, USA –UK: different, single TSO l What went wrong?

US/Canada l 50M people affected, 11% of Eastern Interconnection l Widely covered l Here only short description after US/Canada Power System Outage Task Force “Interim Report: Causes of the August 14 th Blackout in the United States and Canada” Nov

NE of USA/Canada: before

NE of USA/Canada: after

How it all started: tree flashover Source: Gerry Cauley, NERC

Effect of a line trip: increased loading on other lines

Effect of a line trip: depressed voltage

Summary for US blackout l Root causes: –tree growth caused flashovers (FE), –inadequate situational awareness at FE due to computer failures –inadequate diagnostic support from MISO due to state estimator failure l Interim report identified root causes but failures do happen l Why a local failure was not contained? l What are the REAL underlying reasons? l Common features with European blackouts

Danish/Swedish blackout: 5 M people l Normal load l 1.1 GW nuclear plant trips in south. Sweden l 5 min later substation fault trips 1.8 GW nuclear plant and 2 lines in south. Sweden l Total: 2.9 GW + 2 lines lost: system not designed to handle l Local blackout perhaps unavoidable but why a cascade?

l Increased power transfers over fewer lines l Voltage dropping in Southern Denmark and Sweden l Additionally power and voltage swings l further lines tripped l Voltage collapse, power stations trip and separation l Blackout

Danish/Swedish blackout: summary l Again problems at the border but insufficient coordination less of the issue l Single mechanical fault in a separator triggered double busbar fault– very rare, need to investigate l Dependence of Eastern Denmark on supplies from Sweden l Most “technical” of the blackouts

Italy

l 3 am: import 6.6 GW 24% of total demand, 300 MW over agreed level l Fully-loaded CH line touches tree and trips l Unsuccessful reclosing due to angle stability l 3.11 am: ETRANS informs GRTN (disputed) l GRTN reduces imports by 300 MW (not enough)

l 3.25 another CH overloaded line sags and trips on tree flashover l Italy loses synchronism with UCTE l Dynamic interactions cause fast voltage collapse in Italy l Tie-lines trip almost instantaneously l Island operation: 6.4 GW generation deficit leads to frequency collapse l 10 GW of load shed automatically but 21 out of 50 thermal plants trip by under-voltage relays l Blackout 2.5 minute after separation: whole Italy, except of Sardinia.

Italy: summary l Largest blackout in Europe since WW2 l Over-dependence on imports: –1987 referendum blocked nuclear power –Not enough power stations built l Relatively weak and congested tie-lines l Weak coordination between ETRANS and GRTN –ETRANS did not assess the urgency as the consequences of first outage were in Italy –GRTN could not assess the situation as the first outage was in CH l Angle instability and voltage collapse prevented successful island operation of Italy

Common features of US/Canada and European blackouts l Happened at the boundaries between control areas (countries) l Import areas dependent on transmission from export area l Were allowed to spread due to the insufficient coordinated response (to a lesser extent in Scandinavia) l What are the common underlying reasons? l Interconnection brings significant benefits but may be also a threat

North America l 3 interconnections (Eastern, Western, Texas) l 10 regional reliability councils and over 130 control areas! l balkanisation

Balkanisation

Europe's synchronous areas DC connection Source: P. Bonnard, 2003 IEEE Trans. Distr. Conf

Common patterns in US and Europe l Historically: self-sufficient utilities serving native load l Interconnections: –sharing generation reserves –help each other to deal with disturbances –Also limited coordinated exchanges –Maintaining conservative security margins l Liberalisation: –Uncoordinated cross-border trades (8% of generation in Europe, 4 times increase since 1998 in US) –Transmission systems run closer to the limits

Parallel flows: northern France – Italy trade Source: H-J Haubrich, W. Fritz

Unexpected flows in bottlenecks Source: P. Bonnard, 2003 IEEE Trans. Distr. Conf

Main generic reason for recent cascading blackouts l It is not liberalisation to blame but the way utilities operate l Operational procedures developed in the world of monopolistic, vertically integrated utilities cannot deal effectively with liberalisation, open access and cross-border trades l Phone-based communication l None sees the big picture l Limited exchange of real-time data l No automatic coordinated response to emergencies

The future l Is Mega-TSO a solution? – would probably create more problems than solve – politically unacceptable l New technical, organisational and political solutions needed for coordinated but decentralised operation l Alternative: more blackouts or restrain cross-border trades l Need to limit exchange of commercially sensitive information l Trade off between protecting local area and the whole interconnection

Fallacy: transmission investment will prevent blackouts l Bill Richardson, former US Energy Secretary: “we are superpower with third world grid”. l Underinvested grid suffers from bottlenecks but it may still be operated safely l Converse true l Increase in transmission capacity will be sooner or later used up l back to square one although at higher level Source: D. Kirschen, G. Strbac: “Why investments do not prevent blackouts” UMIST, 2003

Fallacy cntd. l Transmission investment enables competition and reduces prices but does not necessarily improve security in the long term l Operational rules are the key l They need to be adapted to the new situation

UK

UK blackouts l Birmingham and London: local blackouts l Remarkably similar to each other but different from US/European ones l NGC single grid operator in E&W, soon GB l In both cases recently commissioned protection equipment tripped due to wrong settings l Questions asked about commissioning procedures, use of outside contractors, maintenance scheduling, excessive downsizing l Findings not published

Conclusions l The blackouts were disasters waiting to happen l Underlying common reason: utilities need to adapt to liberalisation, open-access and cross-border trades l New framework of decentralised yet coordinated operation needed l It is not over yet!

Recent blackouts in US/Canada and continental Europe: Is liberalisation to blame? Janusz W. Bialek University of Edinburgh, Scotland