RP7 Stakeholder Consultation WEB - Flipbook - Page 37
We also acknowledge that there
are specific situations and locations
where a small number of customers
experience significantly lower levels
of network performance. These are
our Worst Served Customers (WSC).
These lower levels of service largely
occur in sparsely populated rural areas,
generally connected on long overhead
line networks. At the end of 2021 there
were 1,324 WSC as classed under the
Ofgem definition.
Just six high-voltage (HV) circuits
account for 67% of customers classed
as worst served. The aim is to improve
performance on these HV circuits to
reduce the number of worst served
customers. This would cost the average
domestic customer 10 pence per
annum in the RP7 period. For our
commercial customers, this represents
an annual amount between 47 pence
for a small business and £7 for a
medium business. On the other hand,
improving service for all worst served
customers would cost the average
domestic customer 49 pence per
annum. For our commercial customers,
this represents an annual amount
between £2 for a small business and
£31 for a medium business. We believe
that by initially targeting investment in
the top six circuits we are delivering a
balanced approach to investment.
Q16. Do you agree with our
approach or should we aim to
eradicate all existing worst served
customers in RP7?
There are also parts of our network
which could, under High Impact Low
Probability (HILP) events, experience
widespread and prolonged outages.
An example of such an event is where
equipment at one substation site is off
supply for prolonged maintenance and
the back-up equipment at the same
substation fails. Each of these sites will
have capability to get some customers
quickly restored, however, this will not
be for 100% of customers connected
at that site. Whilst these events occur
very infrequently they can result in
thousands of customers remaining off
supply for several days to weeks.
To understand how we compare
with our colleagues in GB, we
commissioned some consultancy
research. This research concluded
that on average, for similar types of
substations in GB, approximately 82%
of customers can be kept on supply
following one of these HILP events at
a large substation. However, current
analysis indicates that for equivalent
substations in Northern Ireland, on
average, less than 70% can be kept
on supply.
Our current proposals for RP7 include
investment to improve the number of
customers that we can keep on supply
following a HILP event and move closer
to the GB average. We estimate that
the costs to the average domestic
customer during RP7 to move closer
to the GB average, would be 18
pence per annum. For our commercial
customers, this represents an annual
amount between 78 pence for a
small business and £12 for a medium
business.
17. Do you agree that we should
Q
invest in this area?
RP7 Stakeholder Consultation
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