The System availability indicates the percentage of a PV system that was available over a period of time. This allows e.g. evaluate how quickly faults were identified and remedied. The conditions can be flexibly adjusted using an editor in VCOM.
- Plant availability is only calculated during intervals where Irradiance is above 100 W/m². For the inverter level method, every Irradiance reading in the interval must be above 100 W/m².
- Intervals, where energy data is missing, are treated as if the plant is available.
- Plant availability calculations are not available for the current day
- For Premium Partners: Possibility for Parameter adjustments with the availability editor as well as to choose the calculation method (plant level and inverter level)
System availability in VCOM - Standard method
Necessary data:
- E_Z_EVU (energy on plant level)
- G_M0 (irradiance)
- Values are defined as Terms
- Threshold values as per default: 100W/m²
Concept:
Within the measurement interval, the entire plant is either available (100%) or not available (0%). If the energy ≠ 0 within that interval, the availability is 100% for that interval.
| Interval | Irradiance [W/m²] | Energy [kWh] |
Result |
|---|---|---|---|
| I1 | 90 | 10 | Not rated |
| I2 | 125 | 20 | 100% |
| I3 | 200 | 30 | 100% |
| I4 | 80 | 0 | Not rated |
| I5 | 250 | 0 | 0% |
| I6 | 200 | NULL* | 100% |
| I7 | 150 | 30 | 100% |
| I8 | 130 | 20 | 100% |
| I9 | 110 | 0 | 0% |
| Plant availability | 5 / (5+2) = 71.4 % | ||
*NULL means no data available for this interval
System availability in VCOM - Editor
Premium partners can adjust the following parameters using the availability editor
Irradiation threshold
Irradiation from which the availability is calculated
Calculation method
Plant level
Inverter level
Excluded tickets
Periods in which maintenance work was carried out on site, for example, can be excluded from the availability calculation using a ticket.
Weighting according to exposure
If the system availability is weighted by the irradiation, periods with increased irradiation have a stronger effect.