Actions for Mod209 Workgroup
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Transcript of Actions for Mod209 Workgroup
Actions for Mod209 Workgroup
July 15th 2008
Page 2Theme Date Department
Review of minimum base period for AQ calculation Aim to have a twelve months between the two meter reads
forming the AQ base period
Where this cannot be achieved a longer period is assessed first before reducing to a minimum period
Current minimum base period is 6 months and 1 day
Page 3Theme Date Department
Analysis presented as part of review group 177
Data used is data recorder and data logger information from the Demand Estimation sample
Sample size was 3,788 (split between 2,154 SSP and 1,634 LSP)
Data used current live system AQ and daily actual consumption to produce estimated AQ for varying periods after weather correction
Variability was calculated against actual weather corrected consumption for a 12 month period
Page 4Theme Date Department
Variability of estimated AQVariability in AQ dependent on base period
(Random sample of 3800 sites)
0
200
400
600
800
1000
1200
1400
1600
<-1
00
%
-10
0%
to -
50
%
-50
% to
-4
0%
-40
% to
-3
0%
-30
% to
-2
0%
-20
% to
-1
0%
-10
% to
0%
0%
to 1
0%
10
% to
20
%
20
% to
30
%
30
% to
40
%
40
% to
50
%
50
% to
10
0%
>1
00
%
% Error
Co
un
t
Error at 6 month 1 day Error at 9 month
Page 5Theme Date Department
Impact of extended base period on rollover AQ
Longer base period may mean longer between AQ recalculation
Following analysis assesses whether a 6 month base period would provide improvements on continuing with the current AQ
Sample data is consistent with previous analysis
Page 6Theme Date Department
Will benefits be achieved in a change?
For two base periods the analysis assesses those sites where revising the AQ would be closer to actual consumption than the current live AQ
For 6 month base period over 59% of the time it is better to maintain the current AQ
For 9 month base period it is better to maintain the current AQ in only 38% of cases
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
6m+1 improves AQ 9m+1 improves AQ
Revising AQ better
Better to keep old AQ
Page 7Theme Date Department
SSP to LSP Threshold
Data based on sites in 2005/6 and 2006/7 AQ reviews where the site crossed the SSP/LSP threshold at least once
23,916 sites used for the analysis
Results look at the impact on number of rollovers and aggregate AQ of not recalculating where the change is below a tolerance
Additional information concentrating on sites that cross the threshold annually
Page 8Theme Date Department
Threshold tolerance impacts (1)
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
60.00%
70.00%
80.00%
5% 6% 7% 8% 9% 10%
11%
12%
13%
14%
15%
16%
17%
18%
19%
20%
21%
22%
23%
24%
25%
0.00%
0.50%
1.00%
1.50%
2.00%
2.50%
2005/6 % unchanged 2006/7 % unchanged
2005/6 % difference in total AQ 2006/7 % difference in total AQ 0.5% AQ impact
Page 9Theme Date Department
Threshold tolerance impacts (2)
12% Tolerance % unchanged % AQ impact2005/6 53% 0.49% Overstatement2006/7 16% 0.68% Understatement
10% tolerance % unchanged % AQ impact2005/6 49% 0.34% Overstatement2006/7 12% 0.48% Understatement
Page 10Theme Date Department
Threshold Crosser impacts (3)
Considering sites that cross annually:
2005 AQ LSP2006 AQ SSP2007 AQ LSP
No Tolerances 10% tolerance 12% toleranceSSP LSP SSP LSP SSP LSP
2005 4,984 4,984 4,9842006 4,984 3,926 1,058 3,672 1,3122007 4,984 591 4,393 667 4,317
Moved No Tolerances 10% tolerance 12% tolerance2006 4,984 100% 3,926 79% 3,672 74%2007 4,984 100% 3,335 67% 3,005 60%