Know what solar could do for your home before you invest.

How many panels would you need, and would the savings justify the cost? PVNomics Solar Calculator helps you explore the answers using your electricity use, location and local prices. Add battery storage, try different assumptions and see how your plan changes.

Start with a few details. Learn as you go. No account required, and no ads, even in the free version. Your calculator inputs and saved projects stay on your device.

You don't have to understand every setting to get started

Enter your location and monthly electricity use in Simple mode for a starting estimate of system size, panel count, production and cost. Advanced mode lets you explore grid-tied, hybrid and off-grid systems, with more control over your roof, costs and battery needs.

When a term is unfamiliar, the built-in Knowledge base explains it at the level you choose. Start with everyday language and explore the technical explanation when you want more detail.

Find a setup that fits your needs

• Adjust panel wattage, roof tilt, orientation and shading to see how roof conditions affect your estimate.
• Estimate battery storage for your chosen backup duration, with options for lithium and lead-acid batteries.
• Enter local equipment and installation costs, electricity rates and eligible incentives.
• Account for what your utility pays for solar electricity you send to the grid.

Check the months when sunlight is scarce

Planning an off-grid system? A yearly production total doesn't tell the whole story. Explore sizing based on low-sun months, alongside the battery storage needed for your chosen backup duration. See monthly solar production to understand how output changes through the year.

Understand what drives your savings

See estimated first-year savings, payback, 25-year return on investment and lifetime energy cost. Change electricity prices or installation costs to see how they affect the result. Use your estimates to prepare better questions for your installer.

Keep planning without a connection

Core calculations, built-in city solar data, the Knowledge base and saved projects work offline. Choose a city to get started, or optionally use GPS with an internet connection to request location-based historical solar data from NASA POWER.

Go deeper and share your plan with Pro

When you need more control or a report to share, PVNomics Pro adds:

• Scientific mode: adjust peak sun hours, inverter type, DC/AC ratio, temperature coefficient, soiling and wiring losses. Enter module efficiency to estimate the roof area you need.
• Professional PDF reports: share system specifications, financial analysis and monthly production, with your name or company on the report.
• CSV export: explore inputs, results and a 25-year cash-flow projection in your spreadsheet.
• A larger project library: save, search and manage up to 200 local projects.

Start free with Simple and Advanced modes, solar panel and battery sizing, production and financial estimates, the Knowledge base and one saved project.

Choose monthly, annual or lifetime Pro access when you need more. Subscriptions renew automatically unless canceled. Lifetime access is a one-time purchase with no renewal.

Available in English, Arabic, German, Spanish, French, Portuguese, Russian and Uzbek, with light, dark and system themes.

Results are planning estimates. Check your utility's rates and confirm your final design with a qualified installer.

Enter your electricity use and explore your first solar plan.