What is a Peak Sun Hour?

“Do I get enough sun for solar?” is usually the first thought a homeowner has when wondering if solar will work well for them. The total amount of sun is a big factor, but a more important consideration is something called a ‘peak sun hour’. This metric is often also referred to as a ‘peak sunlight hour’ or a ‘peak solar hour’. This is defined as any hour of the day when the earth receives at least 1000 watts of photovoltaic power per square meter. So how many peak sun hours are needed for solar, and how many does your state get? Read on to learn more about Arizona and California shining particularly bright in this metric, and how this affects your solar viability.

How Much Sunlight do Solar Panels Need?

Most experts agree that the minimum needed is an average of 4 sun hours per day to make solar worth it. This, of course, varies a lot because each home needs a different amount of sunlight to make it work depending on overall electric need. Other factors can make a system more efficient in its use of sunlight including the efficiency of the equipment and the pitch of the roof. A Rooftop Solar expert can run the numbers and figure out how this number will vary for your particular house in regard to these factors. Fortunately, folks in Arizona and California don’t have to worry too much about meeting this minimum requirement of hours of peak sunlight needed for solar to be worth it as these two states rank at numbers one and three for the most peak sun hours in the country.

solar insolation map of US

Unbound Solar

Arizona and California: Hours of Peak Sunlight

Arizona receives a peak of a whopping 6.5 sun hours in a day, and California receives 5.82. The average peak sun hours for your location precisely may vary, but with peaks like these, this state is in great shape for solar. This is extremely important for both of these states because we have very expensive electricity and we hit peaks far higher than average for most of the summer when the AC is running. Conveniently enough, this coincides with the time of year when we receive the majority of our peak sun hours.

One other benefit we see in these states where we need so much power is that we can install smaller systems than in places where there is less sun. The smaller the system, the lower the cost and the greater and faster the payback. Arizona and California’s dryer climates also take less of a toll on certain aspects of the system, and Rooftop Solar’s 30-year warranty helps to ensure your investment will last. In general, we live in states where folks tend to know intuitively that solar “just seems like a no-brainer here” and indeed, the amount of sun hours are the greatest factor proving this true.

Rooftop Solar can explore sun hours per day by zip code but most importantly sun hours for your exact property including accounting for any shade. In addition to the natural incentive of the sun, states like Arizona and especially California, with their exorbitant electric prices, create a massive incentive to go solar. The factors laid out here make summer the most important time to go solar along with a few other key incentives: 3 Key Reasons to go Solar in the Summer. Reach out to a Rooftop Solar specialist today to find out what other considerations apply to your house, and how much money the sunlight in your bright state can save you today!

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