Project Cycle Count KPI

Description

The Project Cycle Count KPI estimates the number of full charge-discharge cycles a battery storage system performs in a single day. This KPI is essential for understanding battery utilization and degradation over time.

The KPI is calculated daily and reported as a floating-point number, where 1.0 represents one full cycle (100% discharge followed by 100% recharge, or equivalent cumulative partial cycles).

Methodology

1. Retrieve time-series data for:

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

2. Convert timestamp index:

   • The index is standardized to ensure consistent time stepping.

3. Calculate absolute changes in SOC:

   • Take the absolute difference in SOC between each pair of consecutive time steps.

     $$\Delta {\text{SOC}}_i=\left|{\text{SOC}}_i-{\text{SOC}}_{i-1}\right|$$

4. Sum the absolute changes and normalize by 2:

   • The total cycle count is estimated by summing all absolute SOC changes and dividing by 2. This accounts for the fact that a full cycle consists of both discharge and charge.

     $$\text{Cycle Count}=\frac{1}{2}\sum _i\left|{\text{SOC}}_i-{\text{SOC}}_{i-1}\right|$$

5. Round and store the KPI result:

   • The daily cycle count is rounded to four decimal places and stored as a project-level KPI for the given date.