Solar Panel Sizer
Solar Sizer is a free educational tool for estimating solar panel capacity and calculating energy production requirem...
What Solar Panel Sizer does
Solar Sizer is a free educational tool for estimating solar panel capacity and calculating energy production requirements. It helps users determine the appropriate system sizing based on their specific location, energy consumption patterns, and other relevant factors that influence solar system design. The online calculator enables users to explore different solar panel configurations and understand their corresponding energy output potential under various conditions. By inputting key information about location and energy requirements, users can estimate the panel capacity needed and plan their off-grid setup with greater confidence.
How to use the Solar Sizer Solar Panel Sizer
- 1
Add what you'll power each day by selecting from published typical draws or entering custom loads
- 2
Pick a load type and add it to your daily total; the tool tracks cumulative power needs
- 3
Select your battery bank voltage (12, 24, or 48 V) and set cloudy-day autonomy and depth-of-discharge parameters
- 4
View calculated results for system size, inverter rating, charge controller amps, and recommended panel count based on worst-month sun hours
Best for
Off-grid enthusiasts and DIYers who need a quick, rough estimate of panel count, battery size, and inverter rating for cabins, vans, or tiny homes without hiring a professional installer.
Limitations
- Results are estimates based on typical sun hours and default derating factors
- No unit switching beyond 12/24/48 V battery configurations
- Does not account for local permitting, structural load, or utility interconnection requirements
Solar Panel Sizer FAQ
- Can I use this tool for a grid-tied solar system?
- No, Solar Sizer is designed for off-grid calculations only. It factors in battery storage, cloudy-day autonomy, and charge controller sizing that apply to standalone systems, not grid-connected setups.
- What does “worst-month sun hours” mean and why does it matter?
- The calculator uses the month with the least solar insolation to size your system, ensuring you have enough power even during the darkest period of the year. This prevents under-sizing your array and battery bank.
- How do I choose between MPPT and PWM charge controllers?
- MPPT controllers are recommended for arrays larger than about 200 watts because they harvest 20–30% more energy. PWM controllers are cheaper and work well for small, low-voltage arrays.
- Can I edit the typical load values that the tool suggests?
- Yes, the published typical draws are editable. You can add custom loads and adjust their wattage or hours-per-day to match your actual usage.
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