20160823AVU to Staff 106.doc

AVISTA CORPORATION
RESPONSE TO REQUEST FOR INFORMATION

JURISDICTION: IDAHO DATE PREPARED: 08/17/2016
CASE NO: AVU-E-16-03 WITNESS: Bryan Cox
REQUESTER: IPUC RESPONDER: Jeff Schlect (w/ Dillon)
TYPE: Production Request DEPARTMENT: Transmission Services
REQUEST NO.: Staff - 106 TELEPHONE: [phone]

REQUEST:

Please provide the most recent ColumbiaGrid regional transmission plan and the Company’s most recent Local Transmission Plan. Describe how each of the transmission capital plant investments summarized in Mr. Cox’s Direct Testimony were incorporated into one or both of the regional transmission and local transmission plans.

RESPONSE:

Please see the most recent ColumbiaGrid regional transmission plan (Staff_PR_106 Attachment A - 2016 ColumbiaGrid Update to 2015 Biennial Plan.pdf) and the Company’s Local Transmission Plan (Staff_PR_106 Attachment B - 2015 Avista System Planning Assessment.pdf). Copies of these agreements are being provided in electronic format only due to the voluminous nature. The reliability improvement transmission projects summarized in Mr. Cox’s Direct Testimony are borne from transmission study analyses that are referenced in the Company’s annual transmission system planning assessments. These projects are also incorporated into studies performed under ColumbiaGrid’s biennial transmission planning process either directly by reference where these projects have a direct impact upon neighboring transmission systems, or indirectly by their inclusion in the transmission system powerflow base cases used to perform such analyses. Direct references to these transmission projects in the Company’s and ColumbiaGrid’s assessments are as follows:

Avista Assessment ColumbiaGrid Assessment
Project Reference Reference
Spokane Valley Reinforcement p. 4; p. 161; pp. 189-191 p. 65; p. 85
Noxon Switchyard Rebuild p. 5; pp. 103-104
Westside Rebuild Phase I p. 4; p. 161; pp. 166-188 p. 63; p. 65; p. 85
Transmission Reconductors and Rebuilds
Benton-Othello 115kV p. 4; p. 32; pp. 39-43 p. 63; p. 65; p. 85
Burke-Thompson A&B 115kV p. 5; p. 77; p. 105
CDA-Pine Creek 115kV p. 4; p. 77; pp. 91-94
9th&Central-Sunset 115kV p. 4; p. 161; pp. 193-212
Devils Gap-Lind 115kV p. 5; p. 32; p. 63
Benewah-Moscow 230kV p. 140; p. 150
Addy-Devils Gap 115kV p. 4; p. 32; pp. 37-38
Beacon-Bell-F&C-Waikiki 115kV p. 4; p. 161; p. 236
Cabinet-Noxon 230kV p. 5; p. 77; p. 107
South Region Voltage Control p. 4; p. 121; p. 126
Garden Springs Substation p. 4; p. 161; pp. 212-219 p. 85 (Spokane Area)
Under the Reliability Improvements category, the Distribution Station Rebuilds and SCADA Completion sub-categories include projects that do not impact system topology, i.e. capacity, they are not specifically included in system assessments.

Under the Reliability Compliance category, the NERC Low and Medium Priority Mitigation projects impact line capacity ratings. While not specifically identified in Company or regional assessments, the line capacity ratings supported by these projects are included in the powerflow base case models that are used to perform these assessments.

All other transmission capital projects referenced in Mr. Cox’s testimony (Reliability Compliance, Contractual and Reliability Replacements) either do not impact system topology, i.e. line capacity ratings, or, to the extent they may impact system topology, are reflected in the powerflow base case models used to perform Company and regional system assessments.

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