I caught a mistake that is easy to miss. When you set runSimForSizingPeriods to true in the simControls/EnergySimpar modules, it appends 7 days of information to the results. ReadEPResults returns 8935 items, not the 8767 that I’d expect. I wrongly assumed these sizing calc happened in the background and would not be appended to the readEPResults.
Figured I’d add this little mistake to the forum to help any others who might stumble into it. If you intend to run the Sizing period, be sure to remove the extra values from your annual energy summary.