When you are installing a solar energy system or calculating the amount of power generated by a solar energy system, you will inevitably need to know the peak hours of sunlight in your area. There is a direct correlation between peak sunlight hours and the amount of power generated by solar panels. Once you understand the peak sunlight hours, you will find that many of your doubts have been solved. In this article, we introduce the issues related to peak sunshine duration.

1. What is peak sunshine duration?

Peak sunshine duration is the period of time during which a location experiences an intensity greater than or equal to 1,000 watts per square meter, but this is basically the intense sunlight at midday. Although the sun’s rays are not always this strong, peak sunshine duration is still an important measurement. For any place with sunlight, the total amount of solar energy that solar panels can receive in a day can be converted into peak sunshine hours. This is what we use to determine if a day is a good day for a solar panel installation.

For example, if one area has 5h of peak sunlight and another area has 3h of peak sunlight, then the first area will definitely be more suitable for installing solar panels because solar panels can generate more electricity in this area.

For specific peak sunshine hours, you can check below website.

https://globalsolaratlas.info/

2. Average Peak Sunshine Hours by Country

Due to the different geographic locations and climates of countries around the world, peak sunshine hours vary greatly from country to country. Below are the peak sunshine hours for some countries.

The average peak sunshine duration in Australia is about 5.6kwh/kwp per day.

Western China has an average peak sunshine duration of about 5.4kwh/kwp per day.

Average peak sunshine duration in India is about 5.6kwh/kwp per day

Average peak sunshine duration in North America is about 5.3kwh/kwp per day.

Middle East average peak sunshine duration is about 5.4kwh/kwp per day

Average peak sunshine duration in Russia is about 3.1kwh/kwp per day

Japan average peak sunshine duration is about 3.4kwh/kwp per day

The average peak sunshine duration in the USA is about 3.6kwh/kwp per day.

Average peak sunshine duration in Korea is about 4.4kwh/kwp per day.

The average peak sunshine duration in Canada is about 3.6kwh/kwp per day.

3. How to calculate the peak sunshine duration?

Record data on solar irradiance: Solar irradiance is the amount of solar energy that can be absorbed per unit area, and it is usually measured in watts per square meter. You can usually find the solar irradiance for your area by local weather stations or national solar radiation databases, etc. It is generally not recommended to measure it yourself as you will need to use a photometer with specific technical specifications that we cannot purchase at this time.

Choose a benchmark: nowadays we generally set 1000W/m², which is the optimal solar energy that solar panels can receive in sunny conditions.

Calculating peak sunshine hours: Now that you know the above two figures you have to calculate the peak sunshine hours, you have to use the following formula.

Peak sunshine hours = Solar irradiance (Wh/m²) / Baseline irradiance (W/m²)

If the solar irradiance in your area is 5000Wh/m², then the peak sunshine duration in your area is 5000Wh/m² / 1000W/m² = 5h.

However, this data is only a rough estimate, the specific peak sunshine duration will be affected by many factors.

4. Importance of peak sunlight hours

Estimating energy production: If you want to estimate how much capacity your solar panels can produce or whether your solar system is sufficient to supply your home’s energy needs, you need to know the peak sunlight hours in your area.

Determine the size of your solar system: Whether you are installing solar for home use or commercial use you will need to determine the size of the solar system you are installing. A solar system that is too small will not be able to generate enough power, and a solar system that is too large will cost more.

Layout of solar panels: After knowing the peak sunlight hours, you can choose the best location for your solar panels. This means that you will get the most energy input. If you work with a professional installer, they can also help you choose the best location.

5. Factors affecting peak sunlight hours

Latitude: The distance of different areas from the equator (latitude) is an important factor that affects peak sunlight hours. This is because areas close to the equator receive the most sunlight. However, as you move farther away from the equator, the angle at which the sunlight hits the earth changes from direct sunlight, and the peak sunshine hours become shorter.

Weather: When the weather is relatively clear, there are hardly any clouds accumulating in the sky, and the sunlight can shine directly on the ground. However, when there are dark clouds in the sky, the sunlight has to pass through the clouds in order to reach the ground, which means that most of the sunlight will be refracted back because of the clouds, and only a small part of the sunlight reaches the ground.

Altitude: When the altitude is higher, the air is thinner, which means that the atmosphere is also thinner and less reflective of the sun’s rays, resulting in an increase in peak sunshine hours.

Conclusion:

Once you understand what peak sunlight hours are, what factors affect peak sunlight hours and how to calculate peak sunlight hours, you can maximize the economic benefits of your solar energy system and reduce the payback period of your solar energy system, reducing your financial burden.