20180316AVU to Staff Attachment 14 T.PDF

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AVISTA CORP.
RESPONSE TO REQUEST FOR INFORMATION

JURISDICTION: MONTANA DATE PREPARED: 01/08/2018 CASE NO.: D2017.9.71 WITNESS: Mark T. Thies REQUESTER: Public Service Commission RESPONDER: Patrick Ehrbar
TYPE: Data Request DEPT: State & Federal Regulation
REQUEST NO.: PSC – 008(AVA) TELEPHONE: [phone]
EMAIL: [e-mail]
REQUEST:
If jurisdictions implement divergent requirements regarding the status of electric generating assets in Montana, how do the Joint Applicants plan to address these potential problems? For instance, if Montana
makes approval of the sale and transfer contingent upon the commitments identified in data response
PSC-007(b) and another jurisdiction requires early retirement or accelerated depreciation, how will the
Joint Applicants address the potential operational and ratemaking concerns this situation poses.

RESPONSE:
As stated in response to PSC-007, the Ownership and Operating Agreement for Colstrip Units 3 & 4 does
not provide for a single owner – or any combination of owners other than all six owners collectively – to
commit to a retirement date for the Colstrip generating units. Therefore, Joint Applicants cannot unilaterally commit to alter the retirement date of the Colstrip units. With respect to the other Avista-
owned generating facility in Montana, Noxon Rapids, Joint Applicants have no basis for altering the
retirement date or the remaining useful life for ratemaking purposes in Montana or other jurisdictions.

With respect to the depreciable life of the Colstrip units for ratemaking and/or accounting purposes, if the Commissions in Washington and Idaho approve accelerated depreciation for a generating facility, but
Montana does not have that same condition, the increased costs associated with acceleration in these
jurisdictions would not be passed along to Montana customers. The accelerated costs would be borne by
the Idaho and Washington jurisdictions, only, in this example.

Staff_PR_014(AVA) Attachment T Page 1 of 1