Interim Report
United States and Canada
2
Overview
Re"eased ,ovem'er 1/ 02
Resu"t of an ehaustive 'i-nationa" investigation &or$ing groups
on e"e#tri# system/ nu#"ear p"ant performan#e and
se#urity
*undreds of professiona"s on investigation teams performed
etensive ana"ysis
5
&hat #aused the '"a#$out 819 3irst5nergy "ost its system
#ondition a"arm
system around 0:1pm/ so its operators #ou"dn)t te"" "ater on that
system #onditions were degrading.
35 "ost many #apa'i"ities of its 5nergy 6anagement System from the
pro'"ems that #aused its a"arm fai"ure ; 'ut operators didn)t
rea"i<e it had fai"ed
&hat #aused the '"a#$out 809
As ea#h 35 "ine fai"ed/ it in#reased the "oading on other "ines and
drove them #"oser to fai"ing. 35 "ost 1? 12@$> "ines 'etween 2:2
and :?pm/ 'ut remained unaware of any pro'"em unti" 2:0pm.
35 too$ no emergen#y a#tion to sta'i"i<e the transmission system
or to inform its neigh'ors of its pro'"ems.
&hat #aused the '"a#$out 829
6ISO 835)s re"ia'i"ity #oordinator9 had an unre"ated software
pro'"em and for mu#h of the afternoon was una'"e to te"" that 35)s
"ines were 'e#oming over"oaded and inse#ure.
A5P saw signs of 35)s pro'"ems and tried to a"ert 35/ 'ut was
repeated"y re'uffed.
&hat #aused the '"a#$out 89
19 3irst5nergy didn)t proper"y understand the #ondition of its
system/ whi#h degraded as the afternoon progressed.
35 didn)t ensure the se#urity of its transmission system 'e#ause it
didn)t use an effe#tive #ontingen#y ana"ysis too" routine"y.
35 "ost its system monitoring a"arms and "a#$ed pro#edures to
identify that fai"ure.
After efforts to fi that "oss/ 35 didn)t #he#$ to see if the
repairs had wor$ed.
&hat #aused the '"a#$out 8=9
09 35 fai"ed to ade4uate"y trim trees in its transmission
rights-of-way.
Overgrown trees under 35 transmission "ines #aused the first three
35 2= $> "ine fai"ures.
%hese treeB"ine #onta#ts were not a##idents or #oin#iden#es
%rees found in 35 rights-of-way are not a new pro'"em One
tree over 0) ta"" one 1 years o"d another 1D in
29 Re"ia'i"ity Coordinators did not provide ade4uate diagnosti#
support to #ompensate for 35)s fai"ures.
6ISO)s state estimator fai"ed due to a data error.
6ISO)s f"owgate monitoring too" didn)t have rea"- time "ine
information to dete#t growing over"oads.
6ISO operators #ou"dn)t easi"y "in$ 'rea$er status to "ine status
to understand #hanging #onditions.
Re"ia'i"ity management 819
3undamenta" ru"e of grid operations ; dea" with the grid in front
of you and $eep it se#ure. *O&(
19 !a"an#e supp"y and demand
09 !a"an#e rea#tive power supp"y and demand to maintain
vo"tages
29 6onitor f"ows to prevent over"oads and "ine overheating
9 +eep the system sta'"e
Re"ia'i"ity management 809
=9 +eep the system re"ia'"e/ even if or after it "oses a $ey
fa#i"ity
?9 P"an/ design and maintain the system to operate re"ia'"y
9 Prepare for emergen#ies %raining Pro#edures and p"ans !a#$-up
fa#i"ities and too"s Communi#ations
@9 %he #ontro" area is responsi'"e for its system
&hat didn)t #ause the '"a#$out 819
19 *igh power f"ow patterns a#ross Ohio 3"ows were high 'ut
norma"
35 #ou"d "imit imports if they 'e#ame e#essive
09 System fre4uen#y variations 3re4uen#y was a##epta'"e
29 Eow vo"tages on @B1 and ear"ier 35 vo"tages were a'ove @F
through @B12
35 vo"tages he"d a'ove =F 'efore 1=:= on @B1
&hat didn)t #ause the '"a#$out 809
9 Independent power produ#ers and rea#tive power IPPs
produ#ed rea#tive power as re4uired in their
#ontra#ts
Contro" area operators and re"ia'i"ity #oordinators #an order
higher rea#tive power produ#tion from IPPs 'ut didn)t on @B1
&hat didn)t #ause the '"a#$out 829
=9 Unanti#ipated avai"a'i"ity or a'sen#e of new or out of servi#e
generation and transmission A"" of the p"ants and "ines $nown to 'e
in and out
of servi#e on @B1 were in the 6ISO day-ahead and morning-of
s#hedu"e ana"yses/ whi#h indi#ated the system #ou"d 'e se#ure"y
operated
?9 Pea$ temperatures or "oads in the 6idwest and Canada Conditions
were norma" for August
1
*ow do we $now this( %he %as$ 3or#e investigation team has
over
two hundred eperts from the US and Canada government agen#ies/
nationa" "a'oratories/ a#ademi#s/ industry/ and #onsu"tants
5tensive interviews/ data #o""e#tion/ fie"d visits/ #omputer
mode"ing/ and fa#t-#he#$ing of a"" "eads and issues
&hat happened on August 1 At 1:21 pm/ 3irst5nergy "ost
&hy did so many trees #onta#t power "ines(
%he trees were overgrown 'e#ause rights-of-way hadn)t 'een proper"y
maintained
&hat happened 829 -- Ohio
After the 2= $> "ines were "ost/ at 2:2 pm 35)s 12@ $> "ines
around A$ron 'egan to over"oad and fai" 1? over"oaded and tripped
out of servi#e
0
20
40
60
80
100
120
140
160
180
200
% o
l R a
D al e-W . C
an t on
W .A k r on B
r e ak er
E . i m a-N .! i n
l a "
C an t on C
en t r al # r an sf or m
er
W .A k r on-$
l e a s an t %
al l e
B a & & -W .A
k r on
E . i m a-N e'
i &
er t
C
l o( er ) al e-# or r e "
* t ar - * . C
an t o n
+ 4 , k %
ar ) i n g- C
am
& er l i n
+ 4 , k %
C am
& er l i n-W .A
k r o n
1 , 0 , 4 1
E D #
1 , + 2 0 +
E D #
1 , 4 1 + ,
E D #
1 , , 1 4 1
E D #
1 6 0 , , ,
E D #
&hat happened 89 -- Ohio
&hat happened 8=9 -- #as#ade
!efore the "oss of Sammis-Star/ the '"a#$out was on"y a "o#a"
pro'"em in Ohio
%he "o#a" pro'"em 'e#ame a regiona" pro'"em 'e#ause 35 did
not a#t to #ontain it nor to inform its neigh'ors and 6ISO a'out
the pro'"em
2
&hy the #as#ade stopped 5ar"y "ine trips separated and
prote#ted areas from the
#as#ade 8southern Ohio9.
,et steps
Phase 1 investigation #ontinues ; more data ana"ysis and mode"ing
of the #as#ade
Phase 0 ; deve"op re#ommendations Pu'"i# #onsu"tations in
C"eve"and/ ,ew Hor$/
%oronto to re#eive feed'a#$ on Interim Report and re#ommendations
on how to prevent the net '"a#$out
Eetters and #omments we"#ome to US GO5 and ,atura" Resour#es
Canada we'sites
3ina" report re"eased in ear"y 0.
