Specific Yield KPI

Description

The Specific Yield KPI quantifies how much AC energy is delivered per unit of installed DC capacity. It provides a normalized metric for evaluating site performance independent of plant size and is especially useful for comparing across projects.

This KPI is calculated daily and expressed in units of kWh/kWp.

Methodology

1. Retrieve time-series data for:

   • meter_active_power: AC power delivered by the site over the day.

2. Clean and aggregate the data:

   • Clip negative values to zero to eliminate erroneous readings.
   • Resample data to hourly averages to standardize granularity.

3. Calculate total energy delivered:

   • Integrate the hourly AC power measurements to get total daily energy output in kWh.

4. Normalize by DC capacity:

   • Divide the total energy output by the site’s installed DC capacity (also referred to as kW-peak, or kWp) to get the specific yield.

5. Compute Specific Yield:

   • The formula is:

     $$\text{Specific Yield}=\frac{\sum \text{AC Energy Output (kWh)}}{{\text{Capacity}}_{DC}\text{ (kWp)}}$$

6. Store the KPI result:

   • The resulting value is stored as a project-level KPI for the corresponding date.