What do the letters on a solar panel mean?
Use these seven terms to read the exact panel label, then let the Australian Solar Checker compare the electrical limits. Rated values are references under stated test conditions—not guaranteed field yield.
Open the Australian Solar Checker →01
The values on the label
Plain meaning first, exact electrical limit second.
- W · watt
- The panel’s rated maximum power under its stated test conditions. More watts can charge faster only when the power station can accept that voltage, current and power.
- Vmp · voltage at maximum power
- The working voltage when the panel delivers near its rated maximum power. It must sit inside the power station’s documented solar operating range.
- Voc · open-circuit voltage
- The voltage when no load is connected. Voc rises in colder conditions and the cold-corrected value must stay below the station’s absolute input maximum.
- Imp · current at maximum power
- The working current at the panel’s maximum-power point. Compatible parallel strings add their current.
- Isc · short-circuit current
- A separate safety and protection reference for cables, fuses and input design. Isc is not interchangeable with the normal working-current value Imp.
- Series connection
- Compatible matched panels connected end-to-end. Their voltage adds while current remains approximately that of one matched panel.
- Parallel connection
- Compatible matched strings connected side-by-side. Their current adds while voltage remains approximately that of one matched string.