Design Solar Systemswith Confidence
Free, drag-and-drop solar system design tool. Place real components, connect them, and get automatic wire sizing and safety validation.
No signup required. Free forever.
Features
Everything you need to design a safe solar system
From wire sizing to component compatibility — Solar Planner handles the engineering so you can focus on building.
Real Components
Browse and place real solar panels, controllers, inverters, and batteries from brands like Victron, Renogy, and Epever.
Automatic Wire Sizing
Enter distances between components and get instant wire gauge recommendations based on current and voltage drop.
Safety Validation
We size everything 25% bigger than needed — so if your panel produces 15A, we recommend wire and fuses rated for at least 19A. This built-in safety reserve keeps your system running cool and safe.
Voltage Drop Analysis
Real-time voltage drop calculations for every wire — color-coded green, amber, or red so you know at a glance.
12/24/48V Systems
Full support for 12V, 24V, and 48V systems with connection-specific limits for panels, batteries, and inverters.
Component Compatibility
Automatic checks that your panel Voc won't fry your controller, your battery matches your inverter, and more.
Why Solar Planner
Built by someone who actually uses it
Tired of drawing solar systems on paper and calculating wire sizes by hand? Solar Planner was built to replace the graph paper, the calculator, and the guesswork.
Real Products
Design with real solar components
Browse a curated catalog of panels, controllers, inverters, and batteries from trusted brands. No abstract calculators — real products with real specifications.
Solar Panels
Victron, Renogy, Rich Solar & more
Controllers & Inverters
Epever, Victron, and other trusted brands
Battery Storage
LiFePO4, AGM, and gel batteries
Ready to design your solar system?
Start with a blank canvas or choose a template. Add components, connect them, and get instant safety feedback.