Here''s Exactly How Many Solar Panels to Buy to Power a House
To determine how many solar panels you need for your home, you''ll first need to know how much energy you use per year. You''ll also need to know the type and wattage of
Look at different panels and see what the wattages are. The solar panel wattage is also known as the power rating, and it's a panel's electrical output under ideal conditions. This is measured in watts (W). A panel will usually produce between 250 and 400 watts of power. For the equation later on, assume an average of 320 W per panel.
Solar panel power output can get confusing fast. Is 400 watts good? 420 watts? Should you opt for the 450-watt panel? Is it worth the extra cost? About 97% of home solar panels installed in 2025 produce between 400 and 460 watts, based on thousands of quotes from the EnergySage Marketplace.
For example, a 400-watt solar panel can generate up to 400 watts of electricity when exposed to full sunlight in a controlled test environment. Most residential solar panels in 2025 are rated between 350W and 480W, while commercial modules can exceed 600W. How do manufacturers determine wattage?
About 97% of home solar panels included in EnergySage quotes today have power output ratings between 400 and 460 watts. The most frequently quoted panels are around 450 watts, so we'll use this as an example.
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