24 Jun What solar panel size is best for a typical American home?
So you want to go solar. Most people don’t look back as they enjoy lower electricity bills and the satisfaction of knowing that they are helping to save the planet. There are many decisions to be made, though, as you start installing your system, including panel size and quantity. We asked a team of solar experts to weigh in on these important decisions. Here’s what they had to say:
Julio Daniel Hernandez
Julio Daniel Hernandez is the leader of EnLight.Energy, a home energy upgrade franchise family. During his time in the industry, he has led teams helping families upgrade to solar and other clean energy technologies across the entire nation and has helped others do the same in Tanzania, Kenya, and Mexico among others.
We are big believers in an unbiased approach to helping a homeowner explore their solar options. When thinking of the right panel size, it is important to differentiate between:
- The size of the system overall- This should be chosen based on energy need or desire. Commonly, an energy consultant will recommend a system based on the historical usage of the last 12 months and adjust as possible for any changes that the homeowner communicates. For example, the panels might need to produce more than the homeowner’s past energy use if the homeowner is getting a new pool or switching to electric heating. In contrast, they might need a smaller system if a kid is moving out to college, or if they are also investing in energy efficiency upgrades like LED lights or better insulation for their attic.
- The wattage that each panel will produce- This ranges quite a bit. Technology is improving, and the same standard size panel 5.4 x 3.25 ft. five years ago produced an average of 250 watts where a panel installed today is likely to produce at least 300 watts. Manufacturers like LG and Sunpower make premium panels with even higher production that can reach as much as 415 Watts per panel for residential use.
So how does it all come together? If you have a big piece of land then maybe you have less restriction and can use some of it for a ground-mount system to fit all of your needs. For a typical American home, however, it is more likely to be the result of an equation involving what we need/want in terms of energy production, how much roof space we have and how much sun exposure the roof has. If space is limited, then you can also consider paying a little more to get more production per panel with a premium brand.
As an example, the average American home consumes around 10,000 kwh per year. With decent sun exposure, you might need a system size of about 8 kw to produce that amount of energy. With a 300 watt size panel, you will need around 27 panels. With the standard panel dimensions, you need at least 700 sq ft of eligible roof space for that system.