What are peak sun hours?

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As solar becomes more accessible and affordable, it is vital that we purchase the right equipment for our needs and understand how to get the most out of our solar energy. This includes understanding how ‘peak sun hours’ and other essential concepts can affect your investment in solar panels.

Peak sun hours are the number of hours in a day when solar power is at its maximum production. The peak sun hours vary depending on location and time of year, but it’s typically around midday (noon to 2 pm). Peak sun hours can be measured using solar irradiance data, which allows us to anticipate how much power we can get from a solar installation in a given area.

As we explore peak sun hours and how it impacts your renewable energy investment, it’s important to understand why achieving maximum solar production is vital. The more hours a day of peak sun, the more time you will have to harness clean energy from our nearest star.

What is meant by solar insolation?

Solar insolation is the total amount of solar radiation or electromagnetic energy that a particular location receives from the sun on a given day. The value of solar insolation is described at kWh/m²/day, which refers to how much solar energy a square meter receives in kilowatts-hours.

Generally speaking, your solar system will have the resources needed to produce maximum solar output during peak sun hours.

A peak sun hour = 1000 kWh/m² (or 1000 W/m²) of sunlight per hour.

Suppose your solar system receives 0.4 kWh/m² or 400 W/m² between 9–10 am. This would equate to 0.4 peak sun hours.

Solar insolation is one of the most important factors determining how much energy your solar panels can produce.

What are peak sun hours?

Peak sun hours are defined as the number of hours per day during which the sun’s intensity achieves 1000 watts per square meter.

Essentially, you’re looking at the average amount of light that hits a specific area over a specified period.

What affects peak sun hours?

Peak sun hours vary on the time of year and which state you live in. As a result of living closer to the equator, you will receive more direct sunlight than those who live closer to the poles.

Time of day

Peak solar radiation, or peak sun hours, typically occurs from noon to the early afternoon, when the sun reaches its highest point in the sky.

The sun’s position is at an angle during sunrise and sunset, causing the sunlight to travel parallel to the surface. In addition to this, the atmosphere during these times is denser, which decreases the sunlight intensity on the ground. This is why it is easier to look at the sun during sunrise or sunset than at noon.


Peak sun hours increase during the summer months due to the sun maintaining a higher position in the sky for a longer period throughout the day. As a result, solar panel systems tend to produce more power during these months.

Geographical location 

The average solar radiation received by a solar power system near the equator will produce more power per square meter than one located closer to the poles.

Local landscape

Trees and other natural objects can shade a section of the area receiving solar radiation. The shading causes an average reduction in power output, but actual reduction can vary from hour to hour depending on cloud cover or other local weather conditions.

Local weather

Variations in climate zones can affect your peak sun hours. Likewise, the weather can cause variations in the solar energy that a system receives. Generally, clear skies and calm weather will allow the most solar radiation to reach your panels.

Cloud cover and wind can reduce the amount of power produced and result in dust accumulating on your panels, reducing surface area and ability to produce power.

How much sun do solar panels need?

All solar panels need enough sunlight to function. But how much is enough? This will depend on your home’s energy requirements and how much you would like to offset using solar panels.

Each state will vary in the average peak sunlight hours it receives. And good solar companies will take peak sun hours into account when designing your solar system, as this will directly impact your solar savings.

How do peak sun hours impact me?

The amount of energy a solar panel system produces depends on the percentage of time it has access to the sun’s rays throughout the day and the total surface area of the solar panels.

Solar system sizing

Peak sun hour data can be used to determine the minimum size solar panel system you will require for your home’s energy use. Your solar panel company calculates how many panels are needed based on the average peak sun hours you’ll receive over a year.

Solar savings

The average peak sun hours your home solar panels receive will determine how much sunlight is converted into power. Homes in states with high peak sun hours will receive more power than those with low average hours of sunlight.

Generally speaking, more peak sun = more solar power = more energy converted = more solar savings.

Your ability to go solar

Areas that receive less sunlight or have unpredictable weather may not produce sufficient energy to make investing in solar a good financial decision.

We still encourage you to get in touch with a trusted energy advisor before you come to any conclusions because many homeowners experiencing fewer peak sun hours have significant solar savings!

The best solar panels for capturing the sun’s energy

Not all solar panels are built the same.

The efficiency of your solar panel will determine how much sunlight you convert into energy and the amount of money you save.

When choosing the best solar panels for your home, it’s important to consider their efficiency and power output, as well as the warranty and support they provide.

We’ve tried and tested many solar panels, and none compare to the SunPower A-Series. With a solar efficiency of 22.5% and a power output of 420 watts, these panels will produce more power per inch and save you more money than any other.

Who is SunPower?

SunPower is one of the world’s leading solar companies, providing quality solar panels used in residential and commercial buildings all over North America.

When you buy SunPower solar panels, you get the best warranty available on the market today – 25 years. And with over 36 years of experience, SunPower stands behind its products so you can stand out from the crowd.

To learn more about how SunPower can help take your home solar to the next level, give us a call today!

Average peak sun hours by state

The average peak sun hours vary by state. We’ve compiled a list of states so you can view the sun hours per day that your solar panels will receive.

Summary: Peak sun hours are your friend!

Peak sun hours occur when the sun’s intensity is at its highest in a given location. How much sunlight intensity in a given square meter depends on several factors such as the time of day, year, geographical location, and weather.

Generally speaking, peak sun hours are at it’s highest during the summer in locations closer to the equator.

To yield a good return on investment for your solar panels, they must receive enough peak sunlight hours to power your home. This is just as important as the type of solar panels you choose. High-quality panels will have a higher solar panel efficiency – converting more solar sunlight into energy for your home.

Are you interested in switching to an affordable renewable energy source such as solar power?

Speak to an energy advisor at Solar Gleam Energy to get a quote for a solar panel installation. We tailor solar systems to your energy requirements and aim to offset 100% of your utility bill.


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Daisy Perez

Daisy Perez

Hi, I'm Daisy. I love solar energy! My job is to help people get the most out of their solar panels, and it's so amazing being able to do that every day.

I also enjoy taking trips to Blackwater Falls State Park in West Virginia for some serenity time – it's a great place for me to recharge my batteries and just relax.

But when I’m not doing those things, you can find me at home with my dogs or cooking up something yummy in the kitchen.

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About Solar Gleam

As a certified SunPower dealer, we’re here to help you learn more about solar, so you make an informed decision before making the switch. We’ve put together our best resources on how solar technology works, the role of solar storage, and the process of going solar for you to go through at your own pace.

Learn more about our company here.

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