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