Trends in North American UVM
Trends in North American
Utility Vegetation Management (UVM)
William Porter
Principal Author of
CN Utility Consulting Utility Vegetation
Management Benchmark & Industry
Intelligence (2010)
Trends in North American UVM
Overview
Some Metrics We Are Covering Today:
I.
II.
III.
IV.
V.
VI.
VII.
VIII.
IX.
X.
Snapshot of North American Utilities
UVM Program Drivers
Cycles and Scheduling Methodology
Clearance Requirements
UVM Methods
Production
Customer Issues
Reliability
Regulations
Conclusion
Introduction
Communication of Research and
Development in 2009
I.
Basic Trend In North
American UVM:
Right Tree-Right Place
Sponsors Have Exclusive
Rights to Publication of
Results
Published in a Journal,
Periodical or Trade
Publication
Research Was Inconclusive
Presentation at an Industry
Meeting
II. CNUC Objective:
Discover Industry Best
Management Practices
(BMPs)
Results Were Used to Change
Company UVM Practices
Informally Shared with Peers
at Other Companies
Research Is Still in Progress
Communicated Internally
0%
0%
Introduction
Introduction
SNAPSHOT OF NORTH AMERICAN UTILITIES
Company Type
Company Type
48 Companies
Investor Owned Utility (IOU)
73%
Municipal or Local Utility (MUNI) (PUD)
13%
State or Provincial Utility
8%
State Owned, Investor Participation
2%
Federal
2%
Rural Electric Cooperative Utility (COOP)
2%
0% 10% 20% 30% 40% 50% 60% 70% 80%
SNAPSHOT OF NORTH AMERICAN UTILITIES
Utility Type
Utility Type
Transmission
and
Generation
Company
2%
48 Companies
Distribution
and
Generation
Company
4%
Distribution
Only
10%
Transmission
and
Distribution
Company
21%
Transmission,
Distribution
and
Generation
Company
63%
SNAPSHOT OF NORTH AMERICAN UTILITIES
Service Territory
Service Territory in Square Miles
Average: 43,538 Square Miles
180,000
160,000
140,000
120,000
100,000
80,000
60,000
0
Company Code
Companies #9 and #12 exceed the axis
Company #9 has 2,190,223 square miles
Company #12 has 412,584 square miles
527
719
1,404
470
800
900
1,534
20,000
42
40,000
667
Service Territory in Square Miles
200,000
SNAPSHOT OF NORTH AMERICAN UTILITIES
Service Territory Description – Customer Density
Service Territory Description – Customer Density
Averages: 33% Urban 21% Suburban 38% Rural
44.3 Customers per Kilometre
8% Remote
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1
2
3
4
5
6
7
8 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 27 28 29 30 31 32 33 34 35 36 37 38 40 41 42 44 45 46 47
Remote (Less Than 5 Customers per Mile/Kilometer)
Rural (Approximately 5-25 Customers per Mile/Kilometer)
Suburban (Approximately 25-50 Customers per Line Mile/Kilometer)
Urban (More Than 50 Customers per Mile/Kilometer)
SNAPSHOT OF NORTH AMERICAN UTILITIES
Overhead System Circuit Kilometres
Number of Overhead System Circuit Kilometres
Average: 51,749 Kilometres
300,000
250,000
200,000
150,000
0
Company Code
3,945
1,719
1,636
6,498
4,917
3,365
2,650
2,476
258
50,000
11,911
100,000
5,997
Number of Overhead Circuit Kilometres
350,000
SNAPSHOT OF NORTH AMERICAN UTILITIES
Overhead System Span Kilometres
Number of Overhead System Span Kilometres
Average Excluding Company #16: 22,313 Kilometres
Number of Pole Span Line Kilometres
80,000
70,000
60,000
50,000
40,000
30,000
20,000
10,000
0
#16 Exceeds the Axis
#16 Has 331,607 Kilometres
Company Code
SNAPSHOT OF NORTH AMERICAN UTILITIES
Tree Population
Number of Trees Managed in System
7,000,000
6,000,000
Number of Trees
5,000,000
4,000,000
3,000,000
#18 Exceeds the Axis
#18: 10,000,00
15
17
18
20
21
25
Company Code
250,000
13
100,000
12
66,464
10
200,000
9
8,500
7
200,000
6
222,356
1
12,000
0
40,000
1,000,000
285,000
2,000,000
26
28
29
35
38
40
41
45
46
48
SNAPSHOT OF NORTH AMERICAN UTILITIES
Tree Population
How is your Tree Population Quantified?
Based on Written Responses Describing Tree Inventories
Other
9%
Independent Survey
19%
Random Sampling
29%
Line Clearance Crews
29%
Work Planner
14%
UVM PROGRAM DRIVERS
Program Drivers Ranked in Order of Importance to UVM
Average Ranks With 1 Most Important and 6 Least Important
Prevent Personal Accidents, Property Damage or
Electrocutions Related to Trees in Close Proximity
to Power Lines
Electric Service Reliability
Comply with Specific Laws
Lower Costs
Customer/Property Owner Service
Prevent Fires Related to Tree Power Line Conflicts
0.00 0.50 1.00 1.50 2.00 2.50 3.00 3.50 4.00 4.50 5.00
Average Rankings
The Most Important Program Driver Is at the Top of the Graph
CYCLES AND SCHEDULING METHODOLOGY
Cycle Definitions
Cycle Definitions
43 Companies Gave Written Responses
Elapsed or
Historical Time
Measurement 65%
Other
4%
No Response
10%
Specified Length
21%
CYCLES AND SCHEDULING METHODOLOGY
Cycle Lengths
Average Distribution Cycle Length in Years
Average: 4.4 Years
Median:4 Years
12
Cycle Length in Years
10
8
6
4
2
0
Company Code
Mode: 4 Years
CYCLES AND SCHEDULING METHODOLOGY
Cycle Scheduling Methodology
Cycle Scheduling
Methodology in 2002
Cycle Scheduling
Methodology in 2006
4%
14%
22%
11%
46%
32%
Circuit Only
71%
Grid Only
Combination
By Circuit
Reliability
By Grid
Other
CLEARANCE REQUIREMENTS
California’s Clearance Requirements
Mandatory
Clearance
Requirements
48 Companies
Yes
19%
No
81%
GO 95 Rule 35: California has the
most comprehensive UVM regulation
in North America
Comments made by utilities with
requirements:
• This enhances cycle times.
• They are our major negotiating tool
for obtaining what is proper clearance.
• Clearance requirements set clear
expectations and assist with funding
requests.
CLEARANCE REQUIREMENTS
Mandatory Clearance Requirements
Opinions are Changing
Feelings Towards Mandatory
Clearance Requirements in
2002
No
Opinion
25%
Positive
16%
Negative
59%
Feelings Towards Mandatory
Clearance Requirements in
2006
No
Opinion
38%
Positive
26%
Negative
36%
CLEARANCE REQUIREMENTS
Do They Work?
Companies Were Asked, “ Could You
Achieve 100% Compliance with a
Mandatory Clearance Requirement?”
Companies That Do NOT
Have Mandatory Clearance
Requirements
Don't
Know
21%
No
50%
Yes
29%
Companies That Do Have
Mandatory Clearance
Requirements
Don't
Know
11%
No
22%
Yes
67%
UVM METHODS
Crew Type
Crews by Category for
Distribution
Crews by Category for SubTransmission/Transmission
60 kV and Above
0-59 kV
80%
50%
69%
40%
20%
Aerial
1% Other in 2006
Climbing
2002
Ground
2006
Herbicide
8%
4%
1%
8%
10%
4%
0%
13%
26%
15%
10%
27%
40%
25%
30%
20%
32%
47%
40%
30%
23%
50%
32%
35%
19%
60%
47%
45%
70%
5%
0%
Aerial
Climbing
2002
Ground
2006
Herbicide
UVM METHODS
Herbicide Usage
Do You Chemically
Treat ROWs?
Outer: Transmission
Inner: Distribution
Herbicide Application Methods Used
In 2008
Aerial
1%
Low
Volume
Foliar
15%
No
11%
No
42%
Basal
55%
Yes
58%
Yes
89%
High
Volume
Foliar
29%
UVM METHODS
Special Programs Included in Routine Maintenance
Programs Included in Regular Maintenance of Lines
in 2008
Percent of Companies That Have the Following Programs
Hazard Tree Assessments and/or Treatments
Oak Wilt rescheduling
Diseased Tree programs
Tree mortality programs (Pine beetle, emerald ash borer,
winter kill etc.)
Tree replacement program
Other (please specify)
0%
10%
20%
30%
40%
50%
60%
70%
PRODUCTION
Cost per System Span Kilometre
Total UVM Cost per Distribution System Managed Kilometres in 2008
Average: £524 per Kilometre
Median: £624/km per Kilometre
£1,600
£1,400
Cost/km in GBD
£1,200
£1,000
£800
£600
£400
£200
£0
1
3
12
15
27
30
31
32
33
36
45
72
Company Code
73
74
75
76
77
78
79
80
81
PRODUCTION
Relative Efficiency
Cost per Labour Hour in GBP
and Labour Hours per Kilometre
160
£4,000
£3,500
140
£3,000
120
£2,500
100
£2,000
80
£1,500
60
£1,000
40
£500
20
0
£0
1
12
18
27
30
45
46
72
73
74
75
76
77
78
79
80
81
Company Code
cost/manhour
Averages:
£28.16/Labour Hour
Manhours/km
cost/km
80.73 Labour Hours/km
£1,993/km
Cost per Kilometre in GBP
180
Cost per Labour Hour, Labour Hours per Kilometre and Cost
per Kilometre for Line Clearance in 2008
CUSTOMER ISSUES
UVM Inquiries per Year
Percent of Total Customers that Make Inquiries Each Year
Average: 0.73%
4.50%
4.00%
3.50%
3.00%
2.50%
2.00%
1.50%
1.00%
0.50%
0.02%
0.00%
0.03%
0.01%0.02%
Company Code
CUSTOMER ISSUES
UVM Complaints per Year
Percent of Total Customers That Have Complaints
Each Year
Average: 0.0375%
0.16%
0.14%
0.12%
0.10%
0.08%
0.06%
0.04%
0.02%
0.0003%
0.00%
3
4
5
6
7
9
0.0013%
0.0017%
0.0013%
12 13 14 18 22 24 25 28 29 30 31 32 33 36 38 40 44 46 47
Company Code
CUSTOMER ISSUES
Perceived Customer Disconnect
Is There a Disconnect
Between Industry Standards
and Customers and Is This a
Significant Issue for the Utility
Arborist?
80%
Commentary by Utilities:
70%
Percent Yes
60%
• Customer equates aesthetics
with proper tree pruning, not
aware of utility best
management practices for line
clearance.
50%
40%
30%
20%
10%
0%
Disconnect with Public
2002
Issue for Utility
Arborist
2006
• Although it is getting better,
customer expectations are often
not in sync with safety and
reliability requirements.
CUSTOMER ISSUES
UVM Problem Solving That Requires the Most Time
Ranked the Fifth Activity Out of 40 That Requires the Most Problem Solving
Customer Relations Ranks Tenth
Activities That Require The Most Problem Solving
Federal Regulations
Paperwork
Environmental Issues
Budget Procurement
Customer Complaints
Cost
Local Regulations
VM Program Changes
Data Management
0%
None
10%
20%
Very Little
30%
40%
Some
50%
60%
More than Should Be
70%
80%
90%
Way Too Much
100%
RELIABILITY
Causes for Outages
2008 Causes for Tree Related Outages
Averages: 35% Grow-in
65% Fall-in
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1
3
12
13
15
18
21
30
31
32
33
36
41
72
73
74
75
76
77
78
79
80
81
Company Code
Percent of Total Tree Related Outages Due to Fall-in 2008
Percent of Total Tree Related Outages Due to Grow-in 2008
RELIABILITY
US Reliability Metrics
SAIDI =
SAIFI =
CAIDI =
RELIABILITY
Frequency of Outages Caused by Trees
Percent of SAIFI that is Tree Related in 2006 - 2008
Averages:
33% in 2006
30% in 2007
39% in 2008
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
12
13
15
18
21
30
31
32
33
36
72
73
74
75
76
77
78
79
Company Code
2006 Tree-Related SAIFI/SAIFI
2007 Tree-Related SAIFI/SAIFI
2008 Tree-Related SAIFI/SAIFI
80
81
LAWS AND REGULATIONS
FAC-0003-1
Effect of FAC-003-1 on Reliability
Outages
Increased
0%
Large
Decrease
in Outages
8%
No Effect
Because No
Outages
56%
Small
Decrease in
Outages
20%
Outages
Stayed the
Same
16%
Change in Refusals, Special Agreements,
Temporary Plans
or Postponements Since the Adoption of
FAC-003-1
Decreased
Substantially
4%
Stayed the
Same
50%
Decreased
17%
Increased
Slightly
25%
Increased
Substantially
4%
LAWS AND REGULATIONS
Increase in Activities Due to Federal Regulations
UVM Activities that Changed Since
FAC-003-1 Became Enforceable
Herbicide Usage
Mowing
Media Attention
Off-ROW Pruning
Off-ROW Removals
Property Owner Complaints
Inspections
Enforcing Easement Rights
Audits
0%
10%
Not Applicable
20%
30%
Stayed the Same
40%
50%
Decreased
60%
70%
Increased
80%
90%
CONCLUSION
Measuring Progress
Number of Tree Removals in Thousands
Tree Removals versus SAIFI
200
2000
180
2002
160
2005
140
2001
2004
120
• This Graph Only Includes
Companies with an
Established Hazard Tree
Removal Program
2003
1999
1997
100
1998
80
• Relatively High Correlation
of -0.76 Which Means:
The More Trees Removed, The
Better The Reliability
(In other words: SAIFI is
Reduced)
y = -358415x + 242616
R² = 0.5761
60
40
20
0
0
0.1
Tree Related SAIFI
0.2
0.3
0.4
0.5
CONCLUSION
BMPs and Regulations for Right Tree in The Right Place
1. Clear Concept of Cycle Based Scheduling or
a Replacement for Cycle Scheduling.
2. Cost Effective and Standardized Method of
Tree Inventory/ Work Load Assessment.
3. Capture and Disseminate Research and
Development Results.
4. Address the Customer Complaints
Proactively, Recognizing the Political Force
of an Insignificant Number of Complaints.
5. Keep Open and Debate the Concept of
Mandatory Clearance Distances.