Enter your Monthly Electricity Usage, Bill Offset Goal, and local Daily Sun Hours into the Solar Panel Size Calculator, and it figures out exactly how many Solar Panels You Need — along with your Total System Size, Daily and Annual Energy Production, and the Roof Area Required to fit them all.
Solar Panels Needed
--
Total System Size
--
Daily Energy Production
--
Annual Energy Production
--
Roof Area Required
--
The number of solar panels needed depends on your monthly electricity usage, location's sun hours, and desired bill offset. Typically, a home uses 20-30 panels for complete energy independence.
Modern panels range from 300W to 500W. Higher wattage panels (400W+) are more efficient and require less roof space, but cost more upfront. Consider your roof space and budget when deciding.
Solar panel output = Panel wattage × Daily sun hours × System efficiency × 365 days. A 400W panel in 5.5 sun hours with 85% efficiency produces about 681 kWh annually.
Solar panels reduce electricity bills, increase home value, provide energy independence, and help the environment by reducing reliance on fossil fuels. Many areas also offer tax incentives for solar installations.
Each panel typically requires 15-20 square feet (1.4-1.8 m²). A typical home system of 25 panels needs about 400-500 square feet of suitable south-facing roof space.
Key factors include panel angle and orientation, shading, temperature, inverter efficiency, and wiring losses. System efficiency typically ranges from 75% to 90% depending on installation quality.
Yes, with proper system sizing you can offset 100% or more of your electricity usage. Net metering allows excess production to be fed back to the grid for credits during low-production periods.
Peak sun hours vary by location and season, typically ranging from 3-8 hours daily. Check local solar irradiance maps or weather data for your specific area to get accurate numbers.