RE: Questions about Interval VEE rules


I agree with Valerie & Kathy regarding item 2; item 1 is not so clear.  The
methodology used in examples D & C in Valerie's document are what I thought
would be used.  I think there are 2 important issues here:  1) There is a
flaw, as Valerie pointed out, in using the methodology for examples C & D;
if the power outage is for an extended period of time the first point
(interval) might not be accurate.   Unless we want to add language that
specifies: "use method C or D if  the power outage is less than 2 hours in
length and method A if the power outage exceeds 2 hours in length"  this
problem will exist.  And 2) is the consistency issue concerning power outage
intervals. I agree with Valerie that intervals during power outages must be
considered as actual in order to be consistent with the rest of the
document.         

I just wanted to mention that we are really splitting hairs here!

H. John VanderLinde
San Diego Gas & Electric
Analyst - Customer Service Policy Support
Phone: (619) 654-8380  Fax: (619) 654-8393 
E-mail: jvanderl@sdge.com


> ----------
> From: 	Valerie Nibler[SMTP:valerie@energyinteractive.com]
> Sent: 	Thursday, July 23, 1998 10:22 AM
> To: 	kathy.smith@USTRA.mail.abb.com
> Cc: 	 - (052)estradam(a)sce.com; Roome, Jane;  - (052)MSL6(a)pge.com;  -
> (052)hillrm(a)sce.com;  - (052)garciah1(a)sce.com;  -
> (052)colwella(a)sce.com;  - (052)JECo(a)pge.com;  -
> (052)diane.rihn(a)lgeenergy.com;  - (052)dciruli(a)energyinteractive.com;
> - (052)tom.lofgren(a)cellnet.com;  - (052)VJM3(a)pge.com;  -
> (052)dirksjd(a)sce.com;  - (052)ddc2(a)pge.com; Vanderlinde, H. John;  -
> (052)pswg3web(a)dra1.cpuc.ca.gov;  - (052)pswg(a)dra1.cpuc.ca.gov
> Subject: 	Re: Questions about Interval VEE rules
> 
> <<File: PowerOut.doc>>
> I agree with Kathy's response to Question 2, but I believe that there is
> still some
> ambiguity with respect to my first question.  I have developed some
> examples of what
> we could do when there is a power outage adjacent to the period requiring
> estimation.  They are shown in the attached Word document (saved in Word
> 6.0, but
> let me know if you cannot read it).
> 
> Having now given some thought about how to approach implementation, I
> would argue
> for dropping the statement "Intervals containing a power failure cannot be
> used as
> end points for interpolation" from the rules.  The genesis of this
> statement was our
> agreement not to use days with power outages as reference days for
> creating average
> profiles for estimation.  I think it makes sense not to use days with
> power outages
> as reference days for estimation because those days may not represent
> typical
> usage.  But not using these intervals for interpolation suggests that the
> usage
> during the power outage does not represent actual usage, which is not
> consistent
> with our treatment of power outages in the remaining data.
> 
> Since the goal here is one interpretation of the rules, I would appreciate
> knowing
> how others are implementing this rule.
> 
> Thanks,
> Valerie Nibler
> Energy Interactive
> 510-704-8777
> valerie@energyinteractive.com
> 
> kathy.smith@USTRA.mail.abb.com wrote:
> 
> > Valerie Nibler sent me the following questions regarding interval VEE
> rules.
> > I've attached my thoughts to her questions.  Please let me know if you
> agree or
> > have a different interpretation by COB Friday, 7/31.  I assume we can
> > disseminate the clarifications through the UDC/MDMA and MUG
> groups.....thanks!
> > (No, the VEE work never finishes!)
> >
> > Kathy Smith, ABB
> > 919-250-5429
> > kathy.smith@ustra.mail.abb.com
> >
> > Questions:
> > 1)  Regarding the statement:  "Intervals containing a power failure
> > cannot be used as end points for interpolation."  What intervals should
> > be used as the first and second points for interpolation in the case
> > where there is a power failure adjacent to the period needing
> > estimation?
> >
> > Proposed answer:
> > My understanding is that an interval with a power failure would be
> > treated the same way as an interval that isn't valid.  You would find
> the
> > closest valid interval that is not a power failure to use as the end
> point.
> >
> > 2)  Point of clarification on estimating holidays.  It is my
> > understanding that you should look for holidays in the current and
> > historical periods, and if you do not find three holidays, you should
> > look for as many additional Sundays as required to supplement the
> > holidays.  Average the holidays and the Sundays (a total of three days)
> > to create the average profile.   A contrasting interpretation is:  look
> > for holidays first, if you find only one, use that as the "average", but
> > if you don't find any, then look for Sundays.
> >
> > Proposed answer:
> > I think you should always try for three days.  This may end up being a
> > combination of holidays and Sundays, and current period and historical.
> I
> > think the priority should be:
> > 1.  Holidays in current period
> > 2.  Holidays in historical data
> > 3.  Sundays in current period
> > 4.  Sundays in historical data
> > If you can't find three holidays or Sundays after all this, then you
> would
> > back off to two days or one day, depending on what you can find.
> >
> > For example, if the current billing period had no holidays, and
> historical data
> > had one holiday - use the holiday from historical data, and the two
> Sundays from
> > the current billing period that are closest chronologically to the day
> needing
> > estimation.  (Assumes all the reference days are "good" data.)
> 
> 
> 
.
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