Timing

Timing#

Timing in Hercules is specified by two primary variables:

  • time (float): Time in seconds from time=0 and the zero_time_utc value

  • time_utc (datetime): Time in UTC (Coordinated Universal Time)

The time variable is always mandatory, while time_utc may be required for certain components (e.g., solar components).

Important Metadata#

  • zero_time_utc: The UTC time corresponding to time==0. This is implied by the input data and doesn’t need to be specified explicitly.

  • starttime: The simulation start time value. Required in the input file.

  • start_time_utc: The UTC time corresponding to starttime. Implied by the data.

  • endtime: The simulation end time value. Required in the input file.

Input Requirements#

Both wind and solar inputs require a time column, while time_utc is optional for wind and mandatory for solar. A top-level time column is constructed based on the time step (dt) specified in the input file and logged at the top level of h_dict.

Consistency#

When both wind and solar inputs contain time_utc columns, the HybridPlant class ensures their zero_time_utc and start_time_utc values are consistent and brings them to the top level of h_dict.

Logging#

To save space, time_utc is not logged. However, time, zero_time_utc, and start_time_utc are logged, allowing time_utc to be reconstructed during post-processing.

Diagram#

Timeline Visualization:

time (seconds):    0 -------- starttime -------- endtime
                   |           |               |
                   |           |               |
time_utc:          |           |               |
                   |           |               |
                   v           v               v
                   zero_time_utc start_time_utc end_time_utc
                   (datetime)   (datetime)     (datetime)

Key Points:
• time=0 corresponds to zero_time_utc
• starttime corresponds to start_time_utc  
• time_utc can be calculated as: zero_time_utc + timedelta(seconds=time)
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