Aging Utility Infrastructure -Myths and RealitiesAging Utility Infrastructure -Myths and Realities
Presented by Dan O’Neill
At the Chartwell Distribution Reliability Summit
On March 9, 2007
In Atlanta, Georgia
2
AgendaAgenda
The ‘problem’ as typically stated
The myth of the ‘tsunami’ dispelled
Age-based replacement is imprudent
The real problems of aging infrastructure
How to address the problem
Observations and key questions
3
Most US utilities had a growth spurt in the 1960s-70s…Most US utilities had a growth spurt in the 1960s-70s…
… And as a result, many utilities have a ‘bubble’ of equipment of
that vintage, like the post-war baby boomer bubble in population
… And as a result, many utilities have a ‘bubble’ of equipment of
that vintage, like the post-war baby boomer bubble in population
Growth of Electricity Usage (GWh) in US 1960-2005
0%
1%
2%
3%
4%
5%
6%
7%
8%
9%
10%
1960
1962
1964
1966
1968
1970
1972
1974
1976
1978
1980
1982
1984
1986
1988
1990
1992
1994
1996
1998
2000
2002
2004
10-y
r M
ovA
vg G
row
th R
ates
4
…that caused a ‘bubble’ in some distribution installation, e.g., URD……that caused a ‘bubble’ in some distribution installation, e.g., URD…
• Most companies started ramping
up their URD in the 1960’s
• Some were responding to local
ordinances requiring URD for
residential developments of any
significant size
– E.g., NY in 1967: URD for
developments with 5 or more
• Housing growth is the key driver
– Often a good correlation
between feet installed and
customer growth
– Recessions in 1975 and in
early 1980’s are evident
– In 1990’s some were affected
by local or regional limits to
growth
URD Cable Installation History Company B
0.0
0.5
1.0
1.5
2.0
2.5
1960
1963
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
1999
2002
Cab
le F
t. I
nst
alle
d P
er Y
ear
(Mil
lio
ns)
URD Cable Installation History Company A
0.0
2.0
4.0
6.0
8.0
10.0
12.0
14.0
1966
1969
1972
1975
1978
1981
1984
1987
1990
1993
1996
1999
2002
Cab
le F
t. I
nst
alle
d P
er Y
ear
(Mil
lio
ns)
5
…which could cause a ‘bubble’ of failures in the current era…which could cause a ‘bubble’ of failures in the current era
Scenario 1: “The egg thru the snake”
When the Weibull distribution has a shape value of 30 and a scale value of 25 years,
– the assumed rate of cable failures are tightly bunched around the 25-year point, and
– the profile of predicted cable failures follows the distribution of installations,
– with the peak failures shifted about 25 years in the future (the dispersion adds about three years: the 1973 peak in installations corresponds to a 2001 peak in failures)
Shape = 30Scale = 25 yrs
Predicted Cable Failures
0
20
40
60
80
100
120
19
75
19
79
19
83
19
87
19
91
19
95
19
99
20
03
20
07
20
11
20
15
20
19
20
23
20
27
20
31
Fa
ilure
s (0
00
s)
Assumed Rate of Cable Failures
0%
10%
20%
30%
40%
50%
1 5 9
13
17
21
25
29
33 37
41
45
49
Years Since Installation
Fai
lure
s
Cable Sections Left By Year Installed
0
5001,000
1,5002,000
2,5003,0003,500
4,000
4,5005,000
19
50
19
54
19
58
19
62
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
98
20
02
Sec
tio
ns
Typical data
6
AgendaAgenda
The ‘problem’ as typically stated
The myth of the ‘tsunami’ dispelled
Age-based replacement is imprudent
The real problems of aging infrastructure
How to address the problem
Observations and key questions
7
Wider failure distribution smoothes the installation profile… Wider failure distribution smoothes the installation profile…
Scenario 2: “Smoothing the profile”
When the Weibull shape value is reduced to 10,– the assumed rate of failures are more
dispersed around the 25-year point and– the profile of the predicted failures is a
smoothed version of the distribution of installations,
– with its peak failures shifted about 34 years into the future (from 1973 to 2007)
Predicted Cable Failures-Illustrative-
0
10
20
30
40
50
60
19
75
19
79
19
83
19
87
19
91
19
95
19
99
20
03
20
07
20
11
20
15
20
19
20
23
20
27
20
31
Fa
ilure
s (0
00
s)
Cable Sections Left By Year Installed-Illustrative-
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
19
50
19
54
19
58
19
62
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
98
20
02
Sec
tio
nsShape = 10
Scale = 25 yrs
Assumed Rate of Cable Failures-Illustrative-
0%
2%
4%
6%
8%
10%
12%
14%
16%
1 5 9
13
17
21
25
29
33 37
41
45
49
Years Since Installation
Fai
lure
s
Typical data
8
…With a wide distribution erasing the installation profile…With a wide distribution erasing the installation profile
Cable Sections Left By Year Installed
0
500
1,000
1,500
2,000
2,500
3,000
3,500
4,000
4,500
5,000
19
50
19
54
19
58
19
62
19
66
19
70
19
74
19
78
19
82
19
86
19
90
19
94
19
98
20
02
Sec
tio
ns
Assumed Rate of Cable Failures
0%1%1%2%2%3%3%4%4%5%
1 5 9
13
17
21
25
29
33 37
41
45
49
Years Since Installation
Fai
lure
s
Shape = 2.5Scale = 25 yrs
Peak in 2072 >>
Predicted Cable Failures
0
2
4
6
8
10
12
14
19
75
19
79
19
83
19
87
19
91
19
95
19
99
20
03
20
07
20
11
20
15
20
19
20
23
20
27
20
31
Fa
ilure
s (0
00
s)
Scenario 3: “The egg disappears”
When the Weibull shape value is reduced to 2.5, – the assumed rate of failures are widely
dispersed around the 25-year point and– the profile of predicted failures is virtually a
straight line after the first 25 years, – with its peak failures shifted almost 100 years
into the future
Typical data
9
The third scenario is born out by existing evidenceThe third scenario is born out by existing evidence
• For companies that have done little URD cable replacement, the trend is much like what is pictured in the third scenario:
– Failures increasing at a steady annual rate of about 5 percent, which, with compounding, means a doubling in about 14 years
• With an active replacement program, no such increase will occur, but:
– The replacement itself might need to grow at about 5 percent per year to keep up, until the failure-prone cable is substantially replaced
• The replacement program’s impact can be increased or diminished by how the cable to be replaced is selected:
– It needs to be, as much as possible, worst first
The myth that cable installed in the 1960-70’s had a ‘thirty-year’ life and
so will come ‘crashing down on us’ in the next ten years is just not true.
There is no ‘crashing wave’, only a ‘long swell’ until the worst is replaced
The myth that cable installed in the 1960-70’s had a ‘thirty-year’ life and
so will come ‘crashing down on us’ in the next ten years is just not true.
There is no ‘crashing wave’, only a ‘long swell’ until the worst is replaced
URD Cable Failures
0
1,000
2,000
3,000
4,000
5,000
6,000
19
82
19
85
19
88
19
91
19
94
19
97
20
00
20
03
Fa
ilu
res
Pe
r Y
ea
r
Company A
Company B
10
AgendaAgenda
The ‘problem’ as typically stated
The myth of the ‘tsunami’ dispelled
Age-based replacement is imprudent
The real problems of aging infrastructure
How to address the problem
Observations and key questions
11
Public cries to replace aging infrastructure are increasingPublic cries to replace aging infrastructure are increasing
July 15, 1999, Thursday
Metropolitan Desk
And yesterday, Mr. Giuliani continued his attacks on Con Edison's response as too passive. ''What Con Edison should be saying is here are the things that have to be done to make it virtually impossible for blackouts to take place,'' he said. ''We need more power. We need to purchase more power. We need more alternatives. We need a more modern infrastructure, meaning we have to improve the feeder cables so we have better material. We need to insulate them better.''
(emphasis added)
12
But if the public knew the facts about age & reliability…But if the public knew the facts about age & reliability…
Not cost-effectiveNot cost-effectiveReplacing infrastructure components based on age is one of the least cost-effective ways of improving service
Not method-efficientNot method-efficientThere are better indicators of deterioration than age, e.g., specific failure history, test results, defective types
Not best practiceNot best practiceOther industries have learned not to rely on age for reliability management, e.g., aerospace, automotive, even natural gas pipelines and LDC’s
Relying on age-based replacement for reliability is:
……they would say that age-based replacement is ‘they would say that age-based replacement is ‘imprudentimprudent’ ’ because it is usually a poor use of ratepayer fundsbecause it is usually a poor use of ratepayer funds
……they would say that age-based replacement is ‘they would say that age-based replacement is ‘imprudentimprudent’ ’ because it is usually a poor use of ratepayer fundsbecause it is usually a poor use of ratepayer funds
13
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0 5 10 15 20 25 30 35 40 45 50
Age of cable (years)
Ca
ble
fa
ilu
res
pe
r m
ile
Age-based replacement is almost always an inferior strategyAge-based replacement is almost always an inferior strategy
Because even though failure does increase with age, it does so Because even though failure does increase with age, it does so very graduallyvery gradually, and other methods provide a sharper pencil to , and other methods provide a sharper pencil to
select assets for replacement closer to ‘just in time’select assets for replacement closer to ‘just in time’
Because even though failure does increase with age, it does so Because even though failure does increase with age, it does so very graduallyvery gradually, and other methods provide a sharper pencil to , and other methods provide a sharper pencil to
select assets for replacement closer to ‘just in time’select assets for replacement closer to ‘just in time’
The failure rate The failure rate of 40-year old of 40-year old
cable is cable is about .45 per about .45 per mile, which is mile, which is higher than higher than
average, but the average, but the failure rate of failure rate of cable sections cable sections
that have failed, that have failed, say three times say three times in five years is in five years is
9.0 per mile*, or 9.0 per mile*, or 20 times higher!20 times higher!
The failure rate The failure rate of 40-year old of 40-year old
cable is cable is about .45 per about .45 per mile, which is mile, which is higher than higher than
average, but the average, but the failure rate of failure rate of cable sections cable sections
that have failed, that have failed, say three times say three times in five years is in five years is
9.0 per mile*, or 9.0 per mile*, or 20 times higher!20 times higher!
* E.g., 350 feet per section,
or 15 sections per mile
14
Replacement is only one of the asset management strategies…Replacement is only one of the asset management strategies…
Asset Management Strategies
• Improved standards for new construction
• Preventive maintenance
• Remediation of failure-prone conditions
• Replacement of failure-prone components
• Re-design for redundancy
• Reinforce for capacity
• Inspection and condition monitoring
• Mitigation of effects on customer satisfaction
• Rapid repair and restoration
…and it is usually not the most cost-effective, unless combined
with inspection and monitoring to replace the worst first
…and it is usually not the most cost-effective, unless combined
with inspection and monitoring to replace the worst first
15
There are better replacement criteria than age aloneThere are better replacement criteria than age alone
• Better method of selection
– Number of previous troubles – e.g., URD cable
– Inspection of condition – e.g., Poles. Crossarms
– Due to defective design or ‘vintage’
• (not necessarily the oldest)
• Better reason for selection to replace
– With a capacity upgrade – conductor, transformers
– To fix specific power quality problems or complaints
– With customer contribution for enhanced reliability
• Better timing of replacement
– With road moves or customer work
– To take advantage of a planned outage
– Upon failure or at condition of imminent failure
Why don’t we replace poles by just reading the age on the pole?
Because we have a better method – pole inspection – just
another example of why age-based replacement is imprudent.
Why don’t we replace poles by just reading the age on the pole?
Because we have a better method – pole inspection – just
another example of why age-based replacement is imprudent.
Most poles have a pole mark, with the date of installation
stamped on it. Right?
16
AgendaAgenda
The ‘problem’ as typically stated
The myth of the ‘tsunami’ dispelled
Age-based replacement is imprudent
The real problems of aging infrastructure
How to address the problem
Observations and key questions
17
Utilities should know the ‘trouble-prone’ groups of aging assetsUtilities should know the ‘trouble-prone’ groups of aging assets
• URD cable – especially HMW or unjacketed 170-mil XLPE concentric neutral from the 1960s’-70’s
• Circuit Breakers
– Medium voltage – Air-magnetic metal clad (especially outdoor)
– High voltage – Certain air blast models
– Oil breakers of inferior design
• Poles – as indicated by inspection
• Power transformers – certain designs, locations
• Transformers – CSPs, overloaded, submersed
• Crossarms – ‘chicken wing’ armless construction
• Transmission H-frames – wooden side braces
• Cutouts – Potted porcelain cutouts of the early 1990’s vintage by a certain manaufacturer
• Substation buss – cap-and-pin insulators, i.e. ‘brown glass’
• Pole-top – plastic ties, guards, etc. not protected from UV deterioration
• Arresters – silicon carbide gap-ype arresters
18
For some equipment, there are problems with early ‘vintages’For some equipment, there are problems with early ‘vintages’
Unjacketed 3-phase cable with worn concentric neutral around insulated conductors
• Typical progression of URD types:
– HMW unjacketed (1960’s)
– XLPE unjacketed (1970’s or later)
– XLPE jacketed (1970’s or later)
– TRXLPE jacketed (1980’s to now)
– EPR jacketed (1980’s to now)
• Virtually all is concentric neutral
• Original HMW was un-stranded
• Some went from DB to in-conduit
– Especially in rocky soil
– And some had a period of C-in-C
• Typical insulation by voltage:
– 12kV – 170 mil
– 34kV – 240 mil
* Glossary:
HMW – High Molecular Weight Polyethylene
XLPE – Cross-Link Polyethylene
TRXLPE – Tree-retardant XLPE
EPR – Ethylene Propylene Rubber
DB – Direct Buried
C-in-C – Cable in Conduit (cable pre-inserted)
For most companies, their URD problem is their 34 kV-class or,
for their 15kV-class, the 170-mil HMW unjacketed cable installed
in the 1960’s and 1970’s, if they have not already replaced it
For most companies, their URD problem is their 34 kV-class or,
for their 15kV-class, the 170-mil HMW unjacketed cable installed
in the 1960’s and 1970’s, if they have not already replaced it
19
AgendaAgenda
The ‘problem’ as typically stated
The myth of the ‘tsunami’ dispelled
Age-based replacement is imprudent
The real problems of aging infrastructure
How to address the problem
Observations and key questions
20
Left alone, aging asset failures can be an accelerating problemLeft alone, aging asset failures can be an accelerating problem
For example, in Company A’s URD cable:
• Outages were increasing at 5-6% per year, which means doubling every 12-14 years
• Repair costs were averaging tens of million$ per year, and growing at the same rate
• Customers were experiencing multiple interruptions, with some averaging 3-4 per year on their half-loop, not counting upstream outages from feeder lockouts, trees, etc.
• Replacement spending had been very little, and needed to ramp up to sufficient levels to arrest the growth in outages, and would have to grow to keep up with deterioration
Company A needed to fund a URD cable replacement program that would
arrest the growth of outages and maintain the level like Company B did
Company A needed to fund a URD cable replacement program that would
arrest the growth of outages and maintain the level like Company B did
* URD – Underground residential distribution – typical way of serving a post-1960’s residential subdivision, i.e., 300-5000 feet of usually single-phase, 12-34kV primary voltage cable, direct-buried (not in conduit), connecting 1-30 padmount transformers per half-loop, with 2-10 customers per transformer, so about 50 customers per half-loop (from riser to ‘normally open’ point)
URD Cable Failures
0
1,000
2,000
3,000
4,000
5,000
6,000
19
82
19
85
19
88
19
91
19
94
19
97
20
00
20
03
Fa
ilu
res
Pe
r Y
ea
r
Company A
Company B
21
HL&P addressed its URD problem effectivelyHL&P addressed its URD problem effectively
HL&P 15kV Failures
HL&P 35kV FailuresHL&P (CenterPoint Energy) had the same type of problem as many and addressed it with a combination of Lightning Arrestor (L/A) upgrade and a cable replacement program:
• Key program items– L/A change out program to limit “let-through current”
starting in the mid 1980’s– From 1981 to 2001 all replacement cable was jacketed
cable in conduit, but due to cost and no observed increase in reliability, the installation practice was shifted back to direct buried after 2001
• 35kV Cable– Adopted an aggressive 5 year replacement program (1987
to 1992), funded at $10 million per year, that replaced 95% of the original installed cable
• 15kV Cable– Active policy for the past 10 years of replacing half loops
with 2 or greater failures in a rolling 12 month period. 2005 funding level was $2.4million or a 19 mile replacement program (at $24/ft)
HL&P has leveled the exponential growth of failures, and stabilized failures at an acceptable level, where it has stayed for over a decade. Others can do the same
HL&P has leveled the exponential growth of failures, and stabilized failures at an acceptable level, where it has stayed for over a decade. Others can do the same
22
The solution involves four key questions about the replacement programThe solution involves four key questions about the replacement program
Measuring the right data?
Predicting the right future?
Predicting the right future?
Funded at the right level?
Funded at the right level?
Replacing the right assets?Replacing the right assets?
• Does the utility know:– What causes failures?– How to avoid them?– How much it costs?
• Does the utility know:– What will happen if programs stay as they are today?– Whether there will be a ‘crashing wave’ or a ‘long swell’?– How the future could be changed?
• Does the utility know:– Which cable segments or half-loops are most cost-effective to address?– Whether and when to inject, outsource, directionally bore, etc.?– How to ensure the field replaces what the model assumed they would?
• Does the utility know:– What level of funding would at least stabilize aging asset outages?– What funding would be needed to achieve customer satisfaction?– What funding is needed to at least break-even on repair costs?
Answering these four key questions will allow the utility to
optimally manage its aging infrastructure replacement programs
Answering these four key questions will allow the utility to
optimally manage its aging infrastructure replacement programs
23
Cable Failure
Improper Installation
Mechanical Damage
Mark-outs
Enforce Penalties
Temperature of cable
Manufacturer Defect
Insulation Breakdown
Dig In
Treeing
Rocky Soil
Enforce Trench
StandardsImproper Training
Insulation Thickness/Type
Cable Injection
Cable Replacement
Lightning
One Call
Upgrade to MOV
Arresters around open
New Construction
Jacket/casing missing/broke
Moisture in cable/joint
Rock Bruising
Corrosion Strength
Steam (Ducted)
LoadingVentilation(Ducted)
AddCapacity
Maintain Manholes
Capacity Planning
Thumping
Cathodic Protection
Maintain Cath Prot
Street Crossing
It is important to investigate causes of failure…It is important to investigate causes of failure…
Thermal Instability
Wet Manhole
…in order to know how to fix the problem…in order to know how to fix the problem
24
Minutes per outage
Growth rate of outages
Past outages per mile
Cost permile
The key to optimal replacement is high failure rate…The key to optimal replacement is high failure rate…
Future minutes per year avoided
Dollars spent
Future minutesavoided per yearFuture outages
avoided per year
Future outagesavoided per year
Past outagesper year
Bang per buck
Past outages per year Miles of line
to be replaced
1 $90,000
1.25 45001 min.$2.00
Miles of line to be replaced
Dollars spent
8x x x =
Where:
• $90,000 per mile = 5280 feet/mile x $17 per foot to replace• 8 outages/mile/year = 13 spans/mile x (3 outages per 400ft span in past 5 years)• 25% growth rate = 3 outages in past 5 years becomes 3 outages in next 4 years• 4500 minutes per outage = 50 customers per outage x 90 minutes per outage
The higher the failure rate... …the higher the bang per buck
25
…As well as ways to reduce the unit cost…As well as ways to reduce the unit cost
• Injection is sometimes a cost-effective option
– Guaranteed by some vendors for many years
– Typically half the cost per mile when used on the right
cable
– Not effective with blocking splices
– Does not solve problem of corroded neutral
– Not really an option for replacing individual segments, but
good for half-loops
• Volume can reduce unit cost
– Half-loops get better cost than individual segments
– But not worth it if failure rate of replaced cable drops faster
than unit cost when volume increases
• Use trenchless technology where possible
– Tunneling under driveways, through tree root systems,
etc.
• Take credit for saving O&M, if appropriate
– Repairing future failures can be made easier, e.g., conduit
26
It is crucial to identify and replace the ‘worst first’It is crucial to identify and replace the ‘worst first’
• E.g., most of utilities’ URD cable sections and half-loops has not failed in the last five years. Replacement of that cable would be unnecessary at this time
• A customer satisfaction-driven program would target those half-loops that experienced a high rate of failure, because every segment that fails in the half-loop causes outages to all customers behind that device (the fuse on the riser)
• The replacement program should then be further refined by replacing only those half-loops or sections in the half-loop that have not already been replaced, or that fit certain criteria, e.g., corroded neutral, voltage, etc. The goal is not to replace all of the assets,
but to replace enough of the right assets at the right time to affect the trend of failures
The goal is not to replace all of the assets, but to replace enough of the right assets at the right time to affect the trend of failures
49%
37%
7%3% 3%*
0%
10%
20%
30%
40%
50%
60%
De
vice
s0 1 2 3 4 or
greater
Failures
URD Failures
Distribution of Failure by Half-Loop
(2001-2005)
Possible target of replacement
program
27
With the right approach, an optimal program can solve the problemWith the right approach, an optimal program can solve the problem
Based on the number of miles of cable that fit the criteria of the half-loop program:
• A program of 2x miles of URD cable replacement, beginning in 2007 and rising by y% per year, would stabilize failures at a normal 2007 level
• 2005 was a hot year, like 1999, so a normal 2006 would be less
• An x-mile program would leave failures rising, although at half the rate
Without a replacement (or injection) program, or with
a minimal program, Company A’s URD failures would
continue to double every 12-25 years
Without a replacement (or injection) program, or with
a minimal program, Company A’s URD failures would
continue to double every 12-25 years
Company A URD Cable Failures
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
8,000
9,000
19
82
19
84
19
86
19
88
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
20
08
20
10
20
12
20
14
20
16
Fai
lure
s P
er Y
ear
Actual '82-'05
Projected '82-'16
Repl x mi +y% per yr
Repl 2x mi +y% per yr
28
Elsewhere*, we have shown how to choose the right level of replacementElsewhere*, we have shown how to choose the right level of replacement
From the viewpoint of a prudent company (and its regulator), there are three tests of a replacement program of this type:
1) Trending – What are the trends in spending and outages of this type?• If spending is down while outages are up, more spending is needed
• If spending is level and outages are level, spending may be adequate (but see below)
• Obviously, there are issues in adjustment for weather, costs, productivity, etc.
2) Benchmarking – What are other companies doing in spending and performance?• If other comparable companies are spending more or getting better results, shouldn’t you?
• Obviously, there are reasons why some companies may differ for good reason
3) Modeling – When the process is modeled, what does it indicate the required level of spending should be to maintain performance or improve it to what customers expect?• This is the kind of modeling we have demonstrated above
• There is customer satisfaction data to suggest that the threshold may be around three outages per year – including outages caused by devices upstream of the URD half-loop
• Compared to the other two tests, this one is the most useful if the modeling is done right
A ‘prudent’ replacement program should be designed
with these tests in mind, especially the third
A ‘prudent’ replacement program should be designed
with these tests in mind, especially the third
* See “The Reliability Conundrum – What Is the Right and Prudent Level of Spending on Service?”, Public Utilities Fortnightly, March 2004, by Daniel E. O’Neill
29
AgendaAgenda
The typical problem
A comparison of URD programs
The myth of the ‘tsunami’ dispelled
How to address the problem
Observations and key questions
30
What we have learnedWhat we have learned
Measuring the right data
Predicting the right future
Predicting the right future
Funded at the right level
Funded at the right level
Replacing the right assets
Replacing the right assets
• Capturing the right information during installation and failures, e.g., date installed, insulation type, location and protection device operated, etc. that will enhance the data mining and prioritization process going forward
• Modeled correctly in terms of installation history, failure rate, and replacement/retirement
• No ‘tsunami’, just growth at a compounded rate
• Replacing based upon centralized selection criteria that include failure history, design/model, projected number of customers affected and restoration time, etc.
• Based on trending, benchmarking, and modeling • As a ‘stake in the ground’, at least determine the amount of funding
needed to stabilize failures at current levels, then determine what it would take to achieve customer satisfaction
Answering these four key questions will allow the utility to
optimally manage its aging infrastructure programs
Answering these four key questions will allow the utility to
optimally manage its aging infrastructure programs
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Observations and Key QuestionsObservations and Key Questions
Observations
• Replacement program – Utilities need to implement an enhanced replacement program for aging infrastructure assets, keyed to replacing the ‘worst first’
• Asset selection – Utilities need to select assets with a high rate and impact of failure
• Without such a replacement program, asset failures will continue to double, often in a decade or so, with consequences for repair cost, increased multiple interruptions to the same customers, possible lengthy outages during major events, and accumulation of the inevitable replacement cost
• There is no ‘tsunami’, only a long, high swell, in the sense that failures and costs will continue to rise at about 3-10% per year, doubling in a decade or so. But a replacement program can stabilize the failures, or even reduce them
Key Questions
• Is the current level of failures acceptable, or should the utility aspire to reduce them further?
• Can the utility execute an enhanced replacement program effectively with its current processes?
• Are their other opportunities to reduce and refine the selection process e.g.: life extension, better inspection and maintenance, etc.?
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Questions?Questions?