Depth of Discharge KPI

Description

The Depth of Discharge (DoD) KPI quantifies the average depth to which a battery storage system is discharged during a given day. It is calculated as the inverse of the average State of Charge (SOC). A higher DoD indicates that the battery is being used more deeply, while a lower DoD suggests more conservative usage.

This KPI is useful for assessing operational behavior and wear-and-tear on battery storage systems. It is reported daily as a percentage between 0 and 1, where 1 means fully discharged on average, and 0 means fully charged on average.

Methodology

1. Retrieve time-series data for:

   • project_soc_percent: The State of Charge (%) of the project’s battery storage system.

2. Convert timestamp index:

   • The index is converted to the project’s local timezone for consistent daily aggregation.

3. Calculate average SOC:

   • Take the mean of all State of Charge (SOC) readings for the day. SOC values are expected to be in the range [0, 1].

4. Calculate Depth of Discharge:

   • DoD is the complement of SOC:

     $$\text{DoD}=1-\text{SOC}$$

   • The result is rounded to four decimal places.

5. Store the KPI result:

   • The daily average DoD is inserted as a project-level KPI for the corresponding date.