Inverter Availability
Description
Inverter availability KPIs measure how often each inverter (and, when present, its internal power-conversion modules) is producing at least a minimum power output under valid irradiance conditions.
One daily report is produced containing:
- Inverter Availability – percentage of daylight intervals in which each inverter’s AC power exceeds a user-defined threshold.
- Module Availability – same calculation applied to individual inverter-module channels (only shown if the project reports module-level power).
This report helps identify offline or under-performing inverters, balance-of-plant outages, and data-quality issues.
Parameters (default values)
| Parameter | Purpose | Default |
|---|---|---|
| Available Min (MW) | Minimum inverter (or module) AC power required to count as “available”. | 0 MW |
| Irradiance Min (W/m²) | Minimum plane-of-array irradiance at which availability is evaluated. | 0 W/m² |
| Inverter Availability (%) | Workbook formula – average of all inverter availabilities. | (output) |
| Inverter Module Availability (%) | Workbook formula – average of all module availabilities (shown only if module data exists). | (output) |
Filters
An individual 5-minute interval is excluded from availability calculations if:
- Plane-of-array irradiance ≤ Irradiance Min.
All other samples form the valid daylight set for the day.
Method – Inverter Availability
- Query 5-minute pv_pcs_ac_power and met_station_poa for every inverter in the project.
- Validate irradiance – keep only timestamps where POA > Irradiance Min.
- Evaluate power threshold – for each inverter, flag samples where
[ P_{\text{inv}}(t) > \text{Available Min} ] - Compute availability per inverter
[ A*{\text{inv}}=\frac{\text{count}\left(P*{\text{inv}}> \text{Available Min}\right)} {\text{count(valid daylight samples)}} ] - Export an Excel workbook containing:
- Parameters – editable inputs & live output KPIs.
- Inverter Availability – % available for each inverter.
- Inverter Power – raw 5-minute power time-series.
- Irradiance – POA irradiance (mean + individual sensors).
Availability formulas live in Excel, so users can adjust Available Min or Irradiance Min and see KPIs update instantly.
Module Availability (when reported)
If the project provides PV PCS Module AC Power:
- Repeat Steps 1-4 using module-level power.
- Add sheets – Module Availability and Module Power – mirroring the inverter sheets.