Yahoo! is not affiliated with the authors of this page or responsible for its content.
Enhancing Electric Reliability, Improving Customer Service n
natio
ional
gr d
Enhancing Electric Reliability, Improving Customer Service
CD4115 r
e
liability 5/07 Enhancing
Electric
Reliability,
Improving
Customer
Service
Reliable electric networks are essential to making
sure customers get the service they deserve.
Reliability, therefore, is one of National Grids top
priorities a commitment we have backed up with
significant financial and human resources.
With dependence on electricity increasing, driven by
growing demands for PCs, televisions, microwave
ovens and other appliances, we know residential
and industrial customers are more inconvenienced
than ever by interruptions in service. As expecta-
tions intensify, the need to address customers
demands for reliable electric service at a fair price
has never been greater.
Like many providers across the country, we face
reliability challenges as we contend with increasingly
intense and unpredictable weather conditions, aging
distribution equipment, and other factors. But we
are determined to address them proactively to
improve reliability and enhance customer satisfaction.
National Grid is making major investments in its
infrastructure, to be sure that customers receive
reliable electric service for their energy dollar. We
are proud of our success and we will continue to
upgrade our system.
This critical investment will enable
us to enhance reliable service to
customers and prepare our system
to meet the needs of our region and
communities as we get further into
the 21st century.
Cheryl LaFleur,
Acting CEO
In the US, we expect to spend more than $3 billion
over five years on our system to strengthen reliability.
Weve taken a hard look at our reliability performance
and assessed major causes of service interruptions.
Then we made a bold commitment to upgrade our
transmission and distribution infrastructure and
transform the way our company delivers electricity
to its customers. Measuring and Improving Reliability
Before addressing the specifics of our reliability
program, its important to understand what exactly
constitutes reliable electric service. Utilities use
three basic metrics to measure reliability: SAIFI System Average Interruption
Frequency Index, the number of times the
average customer is without power during
the year. SAIDI System Average Interruption Duration
Index, the time the average customer is with-
out power each year. CAIDI Customer Interruption Duration Index,
the average amount of time customers are
without power when they have a service inter-
ruption. We consider CAIDI a key indicator of
customer satisfaction and are determined to
reduce customer downtime.
Assessing our reliability performance for 2006,
we found that the average National Grid customer
experienced a single power interruption lasting
about 2 hours, excluding major storms. While that
figure is below our expectations, 2006 studies
show that we are performing better than many
of our industry peers when it comes to providing
reliable electric service.
Identifying Causes of Interruptions
and Taking Action
Several factors contribute to service interruptions.
Among the most common are trees, animals and
deteriorating equipment. These, in fact, constitute
50 percent of all our interruptions. Other issues
include adverse weather and lightning, which
account for a combined 10%.
To reduce the frequency and duration of service
interruptions, National Grid is investing in substan-
tial infrastructure improvements updating and
replacing equipment, strengthening transmission
and distribution lines and aggressively managing
trees and other vegetation that cause problems.
Our Augmented Clearance of Trees (ACT) Project
is a major multi-year tree management program
in New England that identifies poorly performing
power lines with chronic tree issues. These
include dead, dying or diseased trees, which are
identified, then reviewed with community arborists
in a public forum and removed at National Grids
expense.
In New York, where increased lightning strikes and
more frequent and intense weather result in trees
bringing down electricity wires and poles, we
have a similar program to actively remove tree
branches that hang over power lines and to
remove trees that are next to our lines and pose a
risk to reliability.
For the 2006-07 fiscal year, crews completed
more than 22,000 removals and pruned more than
10,000 trees to improve reliability and remove
hazardous conditions.
Deteriorated Eqmt
20%
Human
Element/Company
4%
Tree
27%
Intentional
9%
Transmission
3%
Animal
3%
Human
Element/Other
8%
Adverse
Environment
1%
Lightning
8%
Unknown
5%
Substation
10%
Adverse Weather
2%
Transmission NE >=69kV
Transmission NY
Service interruptions for National Grid customers are
shorter than those at many other large utilities.
Causes of Customer Service Interruptions
(based on duration for all interruptions)
National Grids comprehensive reliability plan addresses
common causes of outages.
0
50
100
150
200
2001
2002
2003
2004
2005
2006
S
A
ID
I (
m
inut
e
s
)
SAIDI - National Grid
SAIDI - Other Large Utilites
Amount of Time the Average Customer is Without Power CD4115 r
e
liability 5/07
n
natio
ional
gr d
Investing Heavily in Reliability Improvement
Those successes are the result of National Grids
strategic and growing investment in upgrad-
ing our transmission and distribution infrastructure.
Moreover, we have made major investments to
add, upgrade or replace older equipment, and
taken measures to help minimize damage to our
infrastructure from lightning and animals. These
steps are in addition to such ongoing actions as
inspection and maintenance.
In the first year of our five-year plan we have: Inspected and upgraded more than 1,300 miles
of major electric distribution lines, replacing
fuses, poles, transformers and related equip-
ment. Animal guards and lightning protection
devices were also installed. Replaced approximately 45,000 cutouts, or
line fuses, that isolate portions of a line experi-
encing an outage and prevent the outage from
affecting a larger customer group. Replaced more than 7,000 insulators, more
than 9,000 transformers, and more than
18,000 wood poles. Installed more than 4,000 animal guards and
more than 1,300 lightning arresters.
At National Grid, we are taking a focused and
proactive approach to asset management across
our business. That includes: A targeted inspection program to identify the
areas that require reliability enhancement; A coordinated system-wide program for
replacing equipment, cables, cross-arms and
poles; and An advanced approach to vegetation manage-
ment that will not only help avoid service
interruptions, but will also greatly improve
performance during storms.
Through our reliability program, well focus on
preventing service interruptions and getting the
lights back on as quickly as possible when the
interruptions do occur. We will continue to improve
reliability throughout our service territory. That is
our commitment to our customers, our regulators
and the communities we serve.
25 Research Drive
Westborough, MA 01582
www.nationalgrid.com