recent blackouts in us/canada and continental europe: is liberalisation to blame? janusz w. bialek...

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

6 blackouts within 6 weeks affecting 112 million people in 5 countries

14 August 2003, USA/Canada: max ~62 GW lost, ~50M people, restoration up to a few days

28 August 2003, south London, 724 MW lost, 410k people + Tube & Rail at rush hour, restoration: 40 min.

5 September 2003, east Birmingham, 250 MW lost, 220k people, restoration: 11 min.

23 September 2003, Sweden and Denmark, 5M people, restoration 4 hours

28 September 2003, whole Italy except Sardinia, 57M people, restoration: 4 hours.

Who’s next?

What’s important for people and policy makers?

Electricity prices

Environmental effect

Security of supply

Recent blackouts

All blackouts were transmission-based

No problem with generation adequacy

Systems were not stressed prior to blackouts

Two categories:

– Cross-border trades: continental Europe, USA– UK: different, single TSO

What went wrong?

US/Canada

50M people affected, 11% of Eastern Interconnection

Widely covered

Here only short description after US/Canada Power System Outage Task Force “Interim Report: Causes of the August 14th Blackout in the United States and Canada” Nov. 2003.

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

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 Interim report identified root causes but failures do

happen

Why a local failure was not contained?

What are the REAL underlying reasons?

Common features with European blackouts

Danish/Swedish blackout: 5 M people

Normal load

1.1 GW nuclear plant trips in south. Sweden

5 min later substation fault trips 1.8 GW nuclear plant and 2 lines in south. Sweden

Total: 2.9 GW + 2 lines lost: system not designed to handle

Local blackout perhaps unavoidable but why a cascade?

Increased power transfers over fewer lines

Voltage dropping in Southern Denmark and Sweden

Additionally power and voltage swings

further lines tripped

Voltage collapse, power stations trip and separation

Blackout

Danish/Swedish blackout: summary

Again problems at the border but insufficient coordination less of the issue

Single mechanical fault in a separator triggered double busbar fault– very rare, need to investigate

Dependence of Eastern Denmark on supplies from Sweden

Most “technical” of the blackouts

Italy

3 am: import 6.6 GW 24% of total demand, 300 MW over agreed level

Fully-loaded CH line touches tree and trips

Unsuccessful reclosing due to angle stability

3.11 am: ETRANS informs GRTN (disputed)

GRTN reduces imports by 300 MW (not enough)

3.25 another CH overloaded line sags and trips on tree flashover

Italy loses synchronism with UCTE

Dynamic interactions cause fast voltage collapse in Italy

Tie-lines trip almost instantaneously

Island operation: 6.4 GW generation deficit leads to frequency collapse

10 GW of load shed automatically but 21 out of 50 thermal plants trip by under-voltage relays

Blackout 2.5 minute after separation: whole Italy, except of Sardinia.

Italy: summary

Largest blackout in Europe since WW2

Over-dependence on imports:

– 1987 referendum blocked nuclear power– Not enough power stations built

Relatively weak and congested tie-lines

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

Angle instability and voltage collapse prevented successful island operation of Italy

Common features of US/Canada and European blackouts

Happened at the boundaries between control areas (countries)

Import areas dependent on transmission from export area

Were allowed to spread due to the insufficient coordinated response (to a lesser extent in Scandinavia)

What are the common underlying reasons?

Interconnection brings significant benefits but may be also a threat

North America

3 interconnections (Eastern, Western, Texas)

10 regional reliability councils and over 130 control areas!

balkanisation

Balkanisation

Europe's synchronous areasEurope's synchronous areas

DC connection

Source: P. Bonnard, 2003 IEEE Trans. Distr. Conf

Common patterns in US and Europe

Historically: self-sufficient utilities serving native load

Interconnections:

– sharing generation reserves– help each other to deal with disturbances – Also limited coordinated exchanges– Maintaining conservative security margins

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

Flows through the Belgian Grid on July 14, 1999

0

1000

2000

3000

4000

1 3 5 7 9 11 13 15 17 19 21 23

Hour

Pow

er (M

W)

Unidentified flows

Expected flows

Source: P. Bonnard, 2003 IEEE Trans. Distr. Conf

Main generic reason for recent cascading blackouts

It is not liberalisation to blame but the way utilities operate

Operational procedures developed in the world of monopolistic, vertically integrated utilities cannot deal effectively with liberalisation, open access and cross-border trades

Phone-based communication

None sees the big picture

Limited exchange of real-time data

No automatic coordinated response to emergencies

The future

Is Mega-TSO a solution?

– would probably create more problems than solve– politically unacceptable

New technical, organisational and political solutions needed for coordinated but decentralised operation

Alternative: more blackouts or restrain cross-border trades

Need to limit exchange of commercially sensitive information

Trade off between protecting local area and the whole interconnection

Fallacy: transmission investment will prevent blackouts

Bill Richardson, former US Energy Secretary: “we are superpower with third world grid”.

Underinvested grid suffers from bottlenecks but it may still be operated safely

Converse true

Increase in transmission capacity will be sooner or later used up

back to square one although at higher level

Source: D. Kirschen, G. Strbac: “Why investments do not prevent blackouts” UMIST, 2003

Fallacy cntd.

Transmission investment enables competition and reduces prices

but does not necessarily improve security in the long term

Operational rules are the key

They need to be adapted to the new situation

UK

UK blackouts

Birmingham and London: local blackouts

Remarkably similar to each other but different from US/European ones

NGC single grid operator in E&W, soon GB

In both cases recently commissioned protection equipment tripped due to wrong settings

Questions asked about commissioning procedures, use of outside contractors, maintenance scheduling, excessive downsizing

Findings not published

Conclusions

The blackouts were disasters waiting to happen

Underlying common reason: utilities need to adapt to liberalisation, open-access and cross-border trades

New framework of decentralised yet coordinated operation needed

It is not over yet!

Recent blackouts in US/Canada and continental Europe:

Is liberalisation to blame?

Janusz W. Bialek

University of Edinburgh, Scotland