Solar Power Blog

Solar Energy Potential in the US by Region, Season, and More

Did you know that solar energy is the cheapest and most abundant source of electricity in the world? We sure do. 

Financially, this achievement was officially proclaimed last year as advancements in solar energy production large and small have made today’s solar panels more efficient and affordable than ever. Plus, sunlight is free, so every watt-hour produced by a solar panel is essentially cost and emission-free.

In terms of availability, solar energy is generated anywhere the sun shines!  Here in the United States, the sun tends to shine a little bit differently everywhere you go. While most people learn this the hard way on their Florida vacation, scientists have used this information to devise precise information about the solar energy potential in any US location. 

Solar Us Shop was founded to bring renewable energy to our customers as easily as possible. In this detailed guide, we will provide a quick look at the most important things to know about the sunlight patterns and solar energy potential in your American city, state, or region. 

Regional Solar Potential in the US

regional solar potential in US

 

More than anything else, solar energy potential in the United States is heavily dependent on the panel’s physical location. In the image above, you can clearly see the best regions in the contiguous US for solar power production, stemming primarily from the Southwest.

Although they are not pictured, your assumptions of Alaskan and Hawaiian solar potential are probably correct. Hawaii receives an incredible amount of sunlight (and has tons of solar infrastructure), while any realistic, reliable Alaskan solar power is limited to only the summer season. 
According to data from the National Renewable Energy Laboratory, the state of Nevada has the highest sun index in the United States, followed by Arizona and New Mexico. Bringing up the rear of the list, the states with the lowest sun index include Washington, Oregon, Ohio, and Michigan. 

Solar Energy Potential Throughout the Day

average solar panel production throughout the day

Throughout the course of each day, the intensity of the sun and its position in the sky influence the amount of radiance that can be captured by a solar panel. In the graph above, you can see that solar panels typically have a “peak” production period starting around noon when energy generation is at its highest potential. 

With the combination of sun index and daily power potential, it is possible to calculate the approximate amount of solar power that can be generated by a single panel. Systems should be designed (either fixed in one location or transported) to capture as much sunlight as possible from 11 AM to 2 PM. 

Seasonal Solar Panel Potential in the US

Sun's position in the sky for solar panels during the year
image source: https://www1.eere.energy.gov/solar/pdfs/43844.pdf

Last but not least, seasonality heavily affects solar panel potential in the United States, as the sun’s position and the number of sunlight hours differ throughout the year. In this diagram, you can see that solar panels have been positioned facing south at an angle that captures both the summer and winter sun. 

Obviously, solar power potential is going to be lower in the winter, due to more dark hours throughout the night. Interestingly enough, however, solar panels tend to operate more efficiently in cold weather (like in most electronics) and sunlight reflecting off of snow can even increase solar power potential during peak hours. 

Other Factors Influencing Solar Panel Potential

In any given solar panel system, the actual energy production is going to be heavily influenced by the quality of your materials. In addition to the panel itself, a full-home system with an inverter and wiring will also affect the amount of solar power that can be generated and used. 

While we can certainly talk all day about designing the perfect solar kit, below we will answer some of the most commonly asked questions regarding external factors that influence solar panel production potential in the United States. 

Do solar panels work on cloudy days?

First and foremost, yes, solar panels still work on cloudy days. Although it is true that solar panels produce electricity most efficiently in direct sunlight, the majority of high-quality generators are able to still harness some sunlight on cloudy days. In general, solar panels will produce roughly 10% to 25% of their peak efficiency in overcast conditions. 

Do solar panels work in the snow?

No, if a solar panel is covered in snow, it will not be able to capture light and produce renewable energy. Thankfully, solar panels are usually installed at an angle and their slick surface helps snow slide right off, typically long before any other part of the roof is clear.  

Will solar panels work in the shade?

Much like on a cloudy day, yes, solar panels will still work in the shade. If a tree is limiting the amount of sunlight that can reach a panel, it will produce energy at a far less efficient rate than with direct light. With this in mind, solar panel systems are designed to minimize the amount of unavoidable daily shade. 

Do solar panels work in the rain?

If the sun is still out in some capacity, then yes, solar panels will still be able to work in the rain at a 10% to 20% efficiency rate. Solar panel systems are weatherproof, and the rain is actually very helpful in providing a free cleaning service. Rain washes away built-up dust and debris which can cause a solar panel to produce at far less efficient rates than normal. 

Do solar panels work during a power outage? 

In a grid-tie system, solar panels do not produce electricity during a power outage. However, if you have a battery-backed off-grid solar energy system, then you will still be able to produce and use solar energy during a temporary or prolonged grid power outage. 

Conclusion 

In conclusion, the exact amount of solar energy potential that you can generate will depend on the panels, location, and weather, as well as the time of day and year. Although it is true that potential production is limited for some people, the truth of the matter is that the sun continues to rise each day and solar energy is an incredibly vital resource to the green revolution. 


Want to learn more? Feel free to read all of our solar energy FAQs. 

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