How to use this tool
Use panel-plane winter irradiation, panel orientation, shading and the exact controller and battery limits.
Enter your details
All defaults are editable planning assumptions. Use actual product specifications and site conditions where possible.
How the estimate works
Estimated daily Wh = (the lesser of panel W × system-yield fraction and the input-cap W) × site/month panel-plane sun hours × (1 − shading fraction). This daily approximation cannot model hour-by-hour clipping; confirm the controller, array and winter resource with a competent installer.
Where product limits or site conditions matter, confirm them against the exact model and installation before buying.
Understanding your result
The daily energy figure depends heavily on the panel-plane sun hours entered for the site and season. The output is an estimate for the stated conditions, not a promise of charging through several cloudy winter days.
Choosing the right equipment
Check the power station or controller’s input voltage, current and watt limits before connecting panels. Allow for shading, orientation and battery charging limits; an off-grid system needs site-specific design and poor-weather provision.