A solar calculator for planning and checking photovoltaic systems: how many panels in series and parallel, what voltage, current and power the array will have, and whether it fits your inverter or MPPT charge controller. Based on datasheet values, corrected for cold and hot weather.

PROJECT
• One screen with a diagram of the whole system: panels, inverter, battery, grid
• The status of every part at a glance: OK, warning, danger or missing data
• Wrong values are shown right under the field, with an explanation

MPPT AND INVERTER
• Voc at minimum temperature vs. maximum PV voltage
• Vmp in hot weather vs. the MPPT range (cell temperature from NOCT)
• Current and short-circuit current per MPPT input, Isc max = 1.25 × Isc (IEC 62548)
• PV power per MPPT input
• Inverters with 2, 3 or more MPPT inputs, including asymmetric ones
• Separate strings per MPPT input and automatic panel distribution

SERIES AND PARALLEL
• Vmp, Voc, Imp, Isc and power for series, parallel and series-parallel wiring
• Wiring diagram, I-V and P-V curve

CABLE, PROTECTION AND GRID
• DC voltage drop, power loss, recommended cross-section and gPV string fuses
• Grid: system type (grid-tie, hybrid, off-grid with grid backup or without grid), AC current, recommended breaker, AC cable drop and allowed power

ENERGY, CONSUMPTION AND PAYBACK
• Daily, monthly and yearly production; sun hours for your location from PVGIS
• Consumption vs production by month: coverage, surplus and shortage
• Payback: total cost, yearly savings and years to pay back

BATTERY
• Charge current and time, autonomy, charge voltage and battery range checks

PDF REPORT
• Colour wiring diagram, all checks, monthly energy, battery and result accuracy

MORE
• My panels and my inverters, saved projects, export and import
• App languages: English, Bulgarian, Russian, German, French, Spanish, Turkish, Portuguese, Polish, Romanian, Greek and Italian; light and dark theme; °C / °F, metres / feet
• Works offline (internet is needed only for PVGIS data). Your data stays on your phone

The app is free with a banner ad and 5 free PDF reports. A one-time "Remove ads" purchase removes the ads forever and unlocks unlimited PDF reports.

Results are indicative. Before installation, check the panel and inverter datasheets and local regulations.