Solar Nerd articles about: System Design

If you used The Solar Nerd calculator, you’ll have an estimate of how many solar panels you need to generate all of your electricity. But then the question is: will that many panels actually fit on your roof? You might know the square footage of your house, but that doesn’t tell you the area of roof that’s available to fit solar panels. What you want is a big rectangular area without any shade.

If you’re a homeowner planning to install solar panels, you’ll either be placing the array on your roof, which is facing in a fixed direction, or you’ll be using a ground mount that gives you some flexibility about where to point them. Especially if you live in a city, you might not have much choice about the direction to face your panels. For example, you might have trees shading one side of your home.

According to the latest data collected by Berkeley Lab, the average size of a home solar installation in the United States is 7 kilowatts (7,000 watts). Kilowatts is a measure of how much electricity the system can generate at a point in time under ideal conditions. Using the highest efficiency solar panels on the market, a solar system can achieve 7 kW of power output with only 16 panels. At the time of writing, the SunPower M-Series is the highest efficiency panel available, with a maximum efficiency of 22.