20201007INT to Staff Attachment 12 CPA Appendix D.pdf

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APPENDIX D. CLIMATE ZONE MAP
The IGC Potential Model will takes into considerations the two climate zones where IGC’s customers are located.
Specifically, the customer database was segmented into the respective climate zones, based on the following
climate zone map.

For weather-dependent measures (heating system upgrades, insulations, etc.), each measure is distinctly
included in the model to capture different saving levels for participants in each climate zone. Several of our
measure characterizations are algorithm based, and explicitly take into considerations the heating degree days
(HDD) to calculate savings; these measures will use the relevant HDDs for each zone, as presented in Table 20
below. Cooling Degree Days were also used for measures with secondary cooling impacts.

Figure 35 : IGC Service Territory and Climate Map

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Table 20: Average HDD and CDD per Climate Zone (2011-2017)
Zone HDDs CDDs
Boise (Zone 5) 5,561 1,416
Idaho Falls (Zone 6) 7,737 799
For other climate dependent measures not explicitly using HDDs as part of their algorithm to calculate savings,
state-wide averages were corrected based on the ratio of HDD in the target zone to the statewide average.