Calculate savings for all days in Reporting Period, even if weather data is missing
Closed this issue · 2 comments
From our review of the current code it appears savings are not calculated for any days in the reporting period with missing weather data. Instead those days are simply removed ("masked"). Hopefully someone can confirm or correct our understanding.
Example: If a project reduces baseline energy use, and 20% of the weather data is missing during the reporting period, 20% of actual savings will be excluded. And any associated payments will be 20% lower than expected.
There is a current discussion in the CalTRACK Methods Draft regarding how to substitute or interpolate missing weather data, but we wanted to raise the issue here as well, as another "Future Improvement" for daily methods.
[Admin: please move to "Existing Daily Methods Improvements"]
This problem could be resolved by separating the disaggregation step (e.g. identifying how much energy correlated with outdoor temperatures) from the final reported savings calculation.
Like the weather data gaps described above, interval data is not always “revenue grade”: there are occasional gaps and errors. HEA learned in 2010 that when presenting energy profiles to customers, our monthly analysis (which uses interval data to disaggregate usage into 5 load types including heating and cooling) must exactly match the customer’s monthly bill total of kWhs and therms. Otherwise customers quickly lose confidence in the results. So whenever interval data does not match bill data (the customer's "truth") we use bill data.
Perhaps CalTRACK could be enhanced to take a similar approach. Otherwise it appears that savings calculations would be based on non-revenue grade data and also contain "missing weather" gaps. Both present unnecessary risks to all P4P parties.