How Many Lumens is The Sun?

Written by John Ho on November 15, 2020
How Many Lumens is The Sun? 2020

Before getting into details of how many lumens is the sun, I want to explain how the sun produces light. The sun has two main elements of hydrogen and helium. A nuclear reaction called fusion occurs every time in the sun. This atomic reaction happens due to a combination of hydrogen atoms to form helium. With this reaction, a massive amount of heat and light is produced. The sunlight is a composition of all seven colors of the rainbow, though it appears white.

How Many Lumens is The Sun?

The light coming from the sun is a combination of electromagnetic radiations in the range of infrared, visible, and ultraviolet. We humans can detect only the visible spectrum of these electromagnetic radiations. The ultraviolet rays also have a positive and negative impact on our life.

You can measure the sunlight intensity in lumens or watts per square meter based on their usage. Lumens is famous in the illumination industry, while the solar energy industry mostly uses watts per square meter.

The luminous efficacy of direct sunlight changes with altitude and the maximum value is around 105 lumens per watt of radiant flux. As standard, you can take luminous efficacy of about 93 lumens per watt of radiant flux.

On the other hand, the light energy reaching the earth's surface is about 1000 watts per square meter. If you multiply both of these values, you can find the lumens in the sunlight, which is about to be 98000 lumens per square meter.

Effect of Sunlight Intensity on Solar Panel Efficiency

As discussed earlier, solar energy reaching the earth's surface is about 1000 watts per square meter. This value is not constant all the time throughout the day. It changes with the time of the day. Moreover, the presence of clouds also changes the amount of light reaching the earth's surface.

While installing a new solar energy system, you can have different solar panels configurations based on the budget and the efficiency you want to achieve. You can install them in a fixed mode where solar panels will face south and not move throughout the day. You can also track the sun to get maximum out of the solar energy system installed.

As the sunlight intensity decreases, the solar panel current starts falling, ultimately reducing the power generated. You can use different solar tracking techniques to track the position of the sun.

Some Famous Solar Tracking Techniques

You can track the sun movement in the sky throughout the day in different configurations based on the system's size and budget allocated. The most well-known and cheapest technique is single-axis solar tracking, where you track the sun on a single axis only. You have to install the solar panels at an angle to the tracking structure, which rotates around a fixed point and faces the sun during the daytime. This technique is suitable for large systems where solar panels are installed in long rows.

In dual-axis solar tracking systems, the system tracks the sun in all three-dimensions with the highest efficiency compared to all other solar tracking systems. You need to install two sets of axis movement equipment compared to a single-axis tracking system. The structure's backbone is a linear actuator available in the market with different lengths and load-bearing capacities.

Installing Solar Energy System in Cloudy Areas

There are regions in the United States and worldwide where the most time of the year remains shadowed with the clouds. Due to this reason, sufficient sunlight cannot reach the earth's surface for better performance of the solar panels. It becomes difficult to recover the money invested instead of getting any profit from the system.

If you live in such an area, I will suggest you not to invest in a solar photovoltaic system, instead use the electricity from the power grid.


Sunlight reaching the earth's surface is vital for the solar energy system to work efficiently and give you a benefit from it. Many websites and software offer a service where you add your location information like latitude, longitude, or zip code. In return, you get information about the annual sun hours, optimum tilt angles, and expected time of getting your investment recovered. I will suggest you do all these analyses during the planning phase. If you do not have enough expertise to do it yourself, you can hire a solar panel installation for their services.

Article written by John Ho

Related Posts