Daylight Savings and SAM

I am doing some system modeling for a peak shaving scenario, basically the on peak period is 11 AM to 6 PM pacific standard time from May to October, does SAM take Daylight savings into account? The time change happens twice during the suggested period. I ask because the system seems to start earlier and end earlier than would be typical for the location.


PS. I can't load rate data for any utility, any one else have this problem?
Happened last week.

No, SAM does not take daylight savings into account.

It makes several other assumptions about time that will affect analysis involving time:

The first row of data in the weather file is for the hour that ends at 1 a.m. on Monday, January 1 local standard time. Any analysis that uses different weekday and weekend schedules assumes that weekdays are Monday through Friday and weekends are Saturday and Sunday.

SAM does not account for leap years, so weather data should not include data for February 29.

As for the trouble downloading electricity rates, the server seems to be working for me now, so I don't think there is a problem with the server. Are you having an intermittent problem, or have you never been able to get it to work?

Best regards,
Paul.

Hi,

Electricity load in SAM results related to what?
I mean if I need system capacity for example 30 kW, the electricity load is much higher than generation.
In this case, what does mean?

Best,
Somayyeh

Dear Somayyeh,

The electric load and system capacity in in SAM are both inputs, so you need to choose a system capacity that is appropriate for your load, or define a load that is appropriate for the system size.

If your results show that the load is always much higher than the system's output, then they show that for that system size and load, the system will not offset very much of the grid purchases needed to meet the load.

Best regards,
Paul.

Are there any plans for SAM to adjust for daylight savings time? If SAM loads rate structures and uses only solar time for production, it will get the wrong answers. SAM is an incredible tool and this enhancement would make it better since almost every U.S. user would benefit.

Thank you for the suggestion.

We are investigating approaches to making SAM's handling of time a more realistic, but it's a bit tricky to do so. For example, not all states in the United States observe daylight savings time, and because daylight savings is a policy, the start and end day for daylight savings time changes from time to time.

Best regards,
Paul.