We estimate that a typical home needs between 17 and 21 solar panels to cover 100 percent of its electricity usage. To determine how many solar panels you need, you’ll need to know: your annual electricity consumption, the wattage of the solar panels you’re considering, and the estimated production ratio of your solar system. You can calculate the number of solar panels you’ll need by dividing the system size by the production ratio, and again by the panel wattage. 

The actual number of panels you’ll need to install depends on factors including your geographic location, panel efficiency, panel rated power, and your personal energy consumption habits. Importantly, the number of solar panels you need for your home directly impacts the price you pay for solar. While the answer isn’t always simple, we’ve put together some example cases to help you understand, at a high level, how many solar panels you need to install an effective home solar array.