I just ran half a dozen trials for a sample solar hot water system for various locations across the United States but the same system configuration, and I keep seeing a dip with in monthly energy saved for the month of August. Is there a bug here for the month of August that needs to get fixed?
The default hot water draw profile has a period from August 12 to August 18 with no hot water demand to represent a household's summer vacation. There are also two other shorter periods in May and December to represent times when there is no demand. During those periods, the system does not save any energy, so you will see a reduction in energy savings.
You can see this clearly after running simulations by displaying the "Hot Water Draw" and "Energy Saved" variables in the Time Series graph on the Results page -- hot water draw is in green and savings are in blue:
Best regards,
Paul.