Loading...
HomeMy WebLinkAbout20070906PAC to Staff 17.pdf~ ~\;o~OUNTAIN p t' (' I: ; " , i I; L: ' / ~. ~, 20 I South Main. Suite 2300 Salt lake City. Utah 84111 September 5, 2007 "n"" L""" C. f,),Q; Luti t.r'- 0 hi I ..... Scott Woodbury Deputy Attorney General Idaho Public Utilities Commission 472 W Washington Boise, ID 83702-5983 IDAf- UT!LI m= Neil Price Deputy Attorney General Idaho Public Utilities Commission 472 W Washington Boise, ID 83702-5983 RE:P AC-07- IPUC Production Data Request 1- Please find enclosed Rocky Mountain Power s 1st Supplemental Response to IPUC Production Request 17. Provided on the enclosed CD is Attachment IPUC Production 17-(1-4) 1st Supplemental. If you have any questions, please feel free to call me at (801) 220-4975. Sincerely, IJ, ~~/~tv- Brian Dickman, Manager Regulation Enclosures Cc:Jean Jewell/IPUC Randall C. Budge/Monsanto James R. Smith/Monsanto Maurice Brubaker/Monsanto Richard Anderson/Energy Strategies Eric Olsen/lIP A Tony Yankel/IIPA Conley Ward/Agrium Dennis Peseau/Agrium Brad Purdy/CAP AI Timothy Shurtz P AC- E-07 -05/Rocky Mountain Power September 5 , 2007 IPUC Production Data Request 17 1 st Supplemental IPUC Production Data Request 17 Please explain the method used to temperature normalize residential and small commercial revenues as per Adjustment 3.1 (McDougal, Exhibit 11). Please provide the model and input data used to determine temperature normalized revenues. 1 st Supplemental Response to IPU C Production Data Request 17 The Company process for weather normalization is to model temperature response by customer by rate code. This measured temperature response is then used with the NOAA normal temperatures and the actual temperatures to calculate the weather impact. The Company customers are aggregated by pricing tariff into rate codes in the Company accounting system. The weather normalization process uses the accounting data to do a correlation between average monthly customer consumption and heating and cooling degree days. Heating and cooling degree days are calculated at base temperature of 65 degrees for this correlation. Based on this correlation a decision is made on which rate codes show weat~er responsive customer behavior and which do not. Those that show weather responsive behavior are further modeled. Customers will use electricity differently based on different temperatures. For example when the temperatures are below 50 degrees the customer will typically respond by using heating equipment. When the temperature is greater than 75 degrees a customer may run air conditioning equipment. When the temperature is between 60 and 70 degrees the customer may not run either heating or cooling equipment. To capture the wide variability of customer response the Company models the data with a multivariate adaptive regression spline equation that identifies the points where temperature response changes. The data is further modeled with a least squares regression equation to pinpoint the temperatures where the response changes. These sensitivity coefficients are then used with the difference between the actual and normal temperature to estimate the impact of weather on the energy sales. The estimates sales impacts are then multiplied by the appropriate price to estimate the revenue impact. Attached (Attachment IPUC Production 17 -1 1st Supplemental, Attachment IPUC Production 17 -1st Supplemental) are prints taken from the mainframe computer that show the monthly calculation of the weather adjustments for kwh. During 2006 a review of the schedules being normalized was completed and additional schedules were added to the calculations. At this time customers response to different temperature levels were also reviewed and the temperatures that caused customer to apply space conditioning equipment also changed. Thus the calculations prior to April 2006 are different from the calculations after. Also see attached (Attachment IPUC Production 17 -1st Supplemental) excel file that shoes the further step of multiplying the values by the appropriate price. P AC- E-07 -05/Rocky Mountain Power September 5, 2007 IPUC Production Data Request 17 1 st Supplemental See attachment (Attachment IPUC Production 17 1st Supplemental) for the model input data. (Reed C. Davis prepared this response and is also the recordholder. It has not been determined who will sponsor this response at hearing. Please contact Brian Dickman at 801-220-4975 to discuss this response. IDAHO P AC-O7- ROCKY MOUNTAIN POWER IPUC PRODUCTION DATA REQUESTS 1- ATTACHMENT IPUC PRODUCTION 17 -(1- ON THE ENCLOSED CD