Monitor actual PV production against expected production, add PI alarms to one or all eligible sites, and configure notifications.
Performance index (PI) monitoring detects PV installations that produce less energy than expected. Add it through Add alarm → Performance index (PI) in Advanced alarms, for one installation or all eligible installations in the selected organisation.
PI monitoring is an explicit choice. Automatic dashboard setup never adds this alarm, and new installations are not enrolled automatically.
| Setting | Default | Effect |
|---|---|---|
| Minimum PI (%) | 90% | An alarm opens when the PI for the entire measurement window is below this value. The editor accepts 0.1% to 100%. |
| Measurement window (full days) | 3 days | The number of complete local calendar days to evaluate. Choose 1 to 14 days. |
| Scope | One site | Select one installation or all currently eligible installations in the selected organisation. |
All eligible sites adds an individual rule to each suitable current installation. Existing PI rules are skipped, so adding the same portfolio again does not create duplicate PI rules or change their settings. Repeat this action when you want to include newly added installations. Account limits on monitored sites still apply.
Use Edit alarm to change an existing rule's minimum PI or measurement window. A rule can also be disabled without deleting its settings.
PI (%) = total measured PV energy ÷ total expected PV energy × 100
The calculation sums energy over the measurement window before dividing. It is not an average of the hourly percentages: hours with more expected production have more weight.
Expected production follows the installation's production configuration and applicable targets in Insights. Depending on the configuration, this uses installed PV capacity, panel orientation, location and irradiation data, together with the correction factor and dated PR targets. A supported production plan configured for the installation can also provide the expectation. Review these settings under Features → Targets and in the installation's production settings.
For the irradiation-based expectation, the configured correction factor is used when no dated PR target applies. The fallback factor is 0.8 when no specific correction factor is configured. A target change during the measurement window is applied to its corresponding period.
Performance ratio (PR) compares measured production with theoretical ideal production. PI compares measured production with the configured expected production, which already accounts for the expected performance.
For example, with no curtailment:
| Quantity | Example |
|---|---|
| Theoretical ideal production | 1,000 kWh |
| Expected performance factor | 80% |
| Expected production | 800 kWh |
| Measured production | 720 kWh |
| PR | 72%: 720 ÷ 1,000 × 100 |
| PI | 90%: 720 ÷ 800 × 100 |
With a minimum PI of 90%, this example meets the limit. The alarm opens only below the limit. A PI above 100% means measured production exceeded the configured expectation. PI monitoring can be used independently of a separate PR alarm.
The rule uses complete calendar days in the installation's time zone and leaves one full day for meteorological data to become available. It does not compare an incomplete current day with a full-day expectation.
For example, an evaluation on 25 June with a three-day window covers 21, 22 and 23 June. It excludes 24 June for the weather-data delay and excludes the current day, 25 June. A longer window smooths daily fluctuations; a shorter window reacts to a smaller period of production.
When configured curtailment telemetry indicates production limiting, the affected hours are excluded from both measured and expected energy. Curtailment that is not recorded in the available telemetry cannot be excluded automatically.
The rule needs valid production and reference data for the relevant hours. Missing, incomplete or invalid production, irradiation or configured curtailment data gives No data / PI unavailable. Missing data is not replaced by zero production, does not create a PI underperformance alarm and does not confirm recovery from an existing alarm.
The result is also unavailable when there is no expected production or when the entire evaluated production period is excluded because of curtailment. Eligibility at setup confirms that a calculation can be configured; it does not guarantee that all historical measurements have arrived.
The analysis graph shows hourly PI values. The displayed overall result and alarm decision use the energy totals for the entire window. A single hourly dip below the line does not by itself trigger the period alarm, and averaging the plotted percentages will not necessarily reproduce the overall PI.
Creating PI rules enables monitoring in the dashboard. It does not create or activate email recipients.
Emails bundle newly opened alarms and confirmed recoveries. Repeated evaluations of the same open condition do not produce a new notification each time. You can leave a recipient inactive while checking the dashboard results. See Notifications for the shared delivery behaviour.
| What you see | What to check |
|---|---|
| An installation is unavailable during setup | Check its production measurements, PV configuration and applicable targets. The editor lists a reason for each unavailable site. |
| PI remains unavailable after saving | Check production, irradiation and any configured curtailment series for the evaluated dates. Wait for delayed source data to arrive; the weather-data lag is already included in the window. |
| A production plan on child devices is not supported | Review the production plan at installation level. The rule reports an unavailable result rather than ignoring unsupported child-device targets. |
| The selected window requires too much detailed data | Select fewer days, as requested by the message. |
| PI is unexpectedly high or low | Check installed capacity, panel orientation, location, correction factor, dated targets and the production-data mapping. Compare PI with expected production rather than with the PR percentage. |
| A low hourly value does not open an alarm | Compare the overall PI with the minimum; the rule evaluates the full-window energy totals. |
| A new installation has no PI rule | Add it manually, or run All eligible sites again. Automatic setup never adds PI rules. |
| No email arrives | Check the recipient's Active setting, site scope, delivery interval and whether a new alarm or confirmed recovery occurred. |