FortisBC Inc. (FortisBC) Application for a Certificate of Public ...

Account 368.00 - Distribution Line Transformers, represents 8% of the depreciable
plant studied. The retirements, additions and other plant transactions for the period 1960
through 2009 were analyzed by the retirement rate method. This account consists mainly
of the lower voltage overhead and pad mounted line transformers used in the distribution of
electric power within the company’s service area. The original survivor curve as plotted on
page IV-49, indicates retirement ratios that begin early in the accounts life and continue
with relatively consistent retirement ratios through age 43, with remaining plant retiring
quickly thereafter. Operational and management staff interviews did not indicate any
significant reason that the future historic retirement patterns will vary from those
experienced in the past. While it is considered that this account will experience growth over
the next few years, given expected growth in the distribution service areas, to better fit the
historical data a movement from the Iowa 45-L2.5 to 45-R4 was selected for this account.
The 45-R4 curve is a good fit to the historic retirement patterns and is expected to be
indicative of the future retirement patterns.
Appendix BCUC IR1 69.4
Account 364.00 – Distribution Poles, Towers and Fixtures, represents 10% of the
depreciable plant studied. The retirements, additions and other plant transactions for the
period 1960 through 2009 were analyzed by the retirement rate method. This account
consists of the distribution power poles, the insulators and attachments to the power poles
such as cross -arms and guy wires. As indicated in the original survivor curve as plotted on
page IV-43 this account has witnessed a significant amount of retirement activity within the
experience band analyzed, with the pace of retirement ratios increasing at approximately
age 27. While it is expected that this account will continue to experience growth over the
next number of years, it is also expected that the retirement activity in this account in the