In this document
You'll learn how to read the Inverter statistics page (available for simulated PV systems, since app release 2.7.0): the monthly overview of the inverter state distribution chart, the data table with the exact share of time spent in each state (optimum operation, self-clipping, standby, grid power limitation, night slots), why standby can occur when no valid MPPT point is found, and the optimization actions the results point to — reducing the DC/AC ratio, adjusting string sizing, considering battery storage, and verifying the inverter Imax against the module Isc.
The Inverter statistics page shows how the inverters of your PV system spend their operating time across the year. Instead of energy volumes, it reports the share of time slots in each operational state, which reveals how well the inverters are matched to the array and where hardware or grid constraints limit the output.
The page is available in the project's Analysis section under PV statistics → Inverter statistics.
For the other chart groups and an introduction to the Analysis section, see How to read the charts. For the energy lost in each conversion step, including clipping, see PV system losses, and for the production values themselves, see PVOUT and performance ratio (PR).
Prerequisites
Active Solargis Evaluate account.
Evaluate project with simulated PV energy system.
Monthly overview of the inverter state distribution
The Monthly overview of the inverter state distribution chart visualizes the percentage of time slots in each month that the inverters spend in the various states. Each month is shown as a full 100% column, divided into the states described in the section below, so the columns can be compared directly across the year.
Unit | |
|---|---|
X-axis | Month |
Y-axis | Share of time slots in the given state [%] |
How to use it
This visual information can be used in several analyses:
Performance monitoring: High percentages of "Optimum operation" (green) indicate a well-matched DC/AC ratio and efficient string sizing.
Loss identification: "Self-clipping" and "Grid power limitation" help quantify how often your system is capped by hardware or regulatory constraints.
Seasonal trends: Highlights how shorter days (Night slots) or peak summer temperatures/irradiance (Grid power limitation or self-clipping) affect the inverters' ability to stay within the MPPT range.
Inverter state distribution table
The table below the chart provides the precise numerical values corresponding to it, allowing for granular audit-level analysis of the following states:
State | Description |
|---|---|
Night slots | Time slots where no solar irradiance is available, representing the system's natural downtime. |
Grid power limitation | Indicates time slots where the inverter's output was throttled to comply with a site-specific grid injection limit. |
Self clipping | Occurs when the inverter restricts power output because the DC input exceeds the inverter's Pmax or Imax limits. |
Stand by | Time when the inverter is inactive during daylight hours because minimum startup voltage or power thresholds were not met, or a valid MPPT (Maximum Power Point Tracking) point could not be found. |
Optimum operation | Time spent within the manufacturer-specified optimal voltage and current range. |
Note: A valid MPPT point may not be found when the inverter cannot find a valid working point within its I-V-P operational envelope. This typically happens during cold, sunny "clear sky" events. In these cases, low temperatures and high irradiance push the array's electrical output beyond safe limits. The resulting voltage or current exceeds the inverter's input range, maximum current Imax, or power limits Pmax. Because the array's curve shifts completely outside these thresholds, the MPPT cannot "lock" onto a functional point. The inverter remains in standby to protect its internal components from damage.
How to use it
Use the table when you need the exact share of each state rather than the visual proportions — for example, to state in a design review how many percent of the summer time slots are clipped, or to compare two system configurations against each other.
Read the states together rather than in isolation: a low share of optimum operation is only meaningful once you see whether the time went to self-clipping (the array is oversized for the inverter), to standby (the string voltage or the operating envelope is the constraint), or to grid power limitation (the restriction is contractual, not technical). The state that dominates points to the corrective action described below.
Next steps and optimization
Based on the readings displayed in your report, you can take the following actions to improve system yield:
Reduce self-clipping: If clipping percentages are high (e.g., > 5-10% in summer), consider reducing the DC/AC ratio by either adding more inverter capacity or removing a small number of modules to minimize clipping losses.
Minimize standby time: If standby time is significant during daylight, check your string configuration. You may need to increase the number of modules per string to ensure the string voltage consistently exceeds the inverter's "Start" or "Minimum" voltage during daytime hours.
Address grid caps: If "Grid power limitation" is frequent, investigate the feasibility of installing on-site battery storage to capture the excess energy for discharge during non-limited hours.
Hardware verification: Ensure the selected inverter model's Imax (maximum input current) is compatible with the Isc (short circuit current) of your modules, especially if using high-current bifacial panels.