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.
Morgen Henderson is a solar expert and community outreach specialist at Solar Power Authority. She is a firm believer in living green and works hard to spread the word about renewable energy and solar power
A typical American home would need approximately 24 solar panels to cover 100% of its energy use. Here’s how that breaks down:
- The average household consumes around 10,400 kWh (kilowatt-hours) of energy per year, which breaks down to about 30 kWh per day.
- Most places in the United States can get close to 5 hours of peak sunlight each day, so if you divide 30 kWh by 5 hours of peak sunlight, it equals 6. This means you need 6 kilowatts of output if you’d like to cover 100% energy use for your household each day.
- Most solar panels typically produce 250-270 watts under peak conditions, so to produce 1 kilowatt, you would need 4 panels. Since the average household uses 6 kilowatts per day, it would ideally need 24 panels (4 panels X 6 kilowatts = 24)
Conditions and actual solar energy generation can vary depending on where a home is located (weather conditions can affect sunlight exposure) and the size of its roof or yard (a smaller roof may not have space for all solar panels, but there are panels that can be placed in other parts of the yard/ground that receive sunlight).
Andrew Sendy grew up on a farm but first worked professionally as a corporate lawyer for two of Australia’s largest corporate law firms. He ran a pizza shop, and he founded the successful Australian software company Strategic Ecommerce. In 2008 he followed a curiosity into the solar panel installation industry, and he hasn’t looked back.
The optimal size of a solar panel array for a typical American home depends on the size and direction of the roof, the climate, and the electricity consumption of the home. The average 2000 square foot home in the United States uses approximately 1000 kWh per month of power.
Based on the climate in California, this would require a 6.27 kW solar power system to fully offset the energy consumption.
Based on a study using installed solar system data from California in 2018, the best value solar panel (Panasonic VBHN330SA16) has a power output of 330 Watts. This means 19 of these panels are required for a 6.27 kW system. This would require about 32 square meters (344 square feet) of roof space.
The above example makes many assumptions regarding what is “typical,” and there are many variables to consider when trying to calculate the appropriate solar panel size for a home.