Glad you asked! As a solar installation company based out of California, it’s a question that homeowners ask us very often. While many articles give estimates for the nation as a whole, we thought of providing a more specific answer to the number of solar panels you would need if you lived in the golden state of California.

Estimates Based on National Averages

Let’s start with understanding the US national average for the solar industry. Firstly, the standard photovoltaic solar panel generates an average of 250 watts. The average US household consumes around 10,649 kilowatt-hours (kWh) per year and about 849 kWh per month. Based on this estimation, your home will need 20-25 solar panels on the roof to generate all the power it needs. (A kilowatt-hour is how many kilowatts—units of 1,000 watts—are used in one hour. That’s the basis for how your utility company charges you).

Estimates Based on California Averages

In California, the annual total energy consumption per capita is 33% lower than the national average, at just 7000kWh per customer annually. The golden state features in the lower bracket of the national estimates, with Hawaii being the lowest. In Hawaii, the average is only 6000 kWh per customer annually. Californian homes use less power because of the typical mild and beautiful climate, which means less reliance on air conditioning and heating.

Although Californian homes use lesser electricity, the spending is closer to the national average. That’s because of higher energy prices in the state, which, along with state government policies, create more reasons to go solar. Now here’s some good news. SouthWest Sun Solar uses 280-watt solar panels, and you can get a 12% improvement in power output over the standard.

In summation, an average California homeowner who partners with us will only need 16-19 panels.

an average California homeowner who buys from us will only need 16–19 panels.

Calculating Your How Many Solar Panels for Your Home

Now, these are only averages, not accurate figures. So, if you want an error-free estimate, you can easily calculate based on your power consumption. Here’s how you can do it:

Check your total power consumption (kWh used) for the last year. This figure should be on your latest electricity bill. If not, call your utility company, and they’ll give it to you.

Get out your calculator and divide your total kWh used by 1.31 and 1.61. Those two figures are the lowest and highest energy production ratios for solar panels in the US. A production ratio is simply the estimated number of kWh/year a set of solar panels will produce, divided by the total wattage (power-generating capacity) of the set of panels. A higher production ratio usually means a higher percent efficiency.

Divide the two results by 280, which is the wattage produced by one SouthWest Sun Solar panel. That should give you a more accurate range for the number of solar panels you’ll need for your home.

If you’d like to know more, get in touch. We’ll be happy to give you our own estimate, absolutely free.


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