Do Solar Panels Use UV Light?

Life revolves around the sun. We measure time in terms of our revolutions about the sun. Without sunlight, there would be no life on earth. Plants would not grow and there would be no energy to sustain all other forms of life.

That is why some ancient cultures like the Incas, Hindus, and even Romans worshipped the sun. They understood the life-giving essence of the sun’s energy.

It’s on this principle that solar panels are designed and built. To harness the life-giving power of solar energy. This article examines how solar panels use light to create energy.

Solar panels use a small portion of UV to produce energy. This is because ultraviolet light is only a small percentage of the solar spectrum a solar panel receives. The bulk of the light that is converted into electrical energy is visible light.

How Do Solar Panels React To The Solar Spectrum?

Every day the earth receives a spectrum or range of light from the sun. Sunlight is part of the electromagnetic radiation given off by the sun. The solar spectrum is composed of:

1. Visible light is named because it’s the light we can see with our naked eyes. Visible light constitutes 43% of sunlight.
2. Infrared lightconstitutes about 53%.
3. Ultraviolet (UV) lightis about 4%.

The spectrum of almost all solar electromagnetic radiation spans a range of 100 nm to about 1,000,000 nm. UV ranges from 100 to 400 nm. Visible light, the strongest output range of the sun’s total irradiance spectrum, spans 380 to 700 nm. Infrared spans from 700 nm to 1,000,000 nm. (Source)

Solar cells actively respond to many of the same wavelengths of light detected by the human eye. Most of what finds its way into and gets used by electrical equipment as electricity is visible light. Slightly less than half of infrared is converted to electricity and only a small portion of ultraviolet. The reason for this is photons.

Also, find out If Solar Panels Work with Light Bulbs (Artificial Light)?

What Are Photons?

The sun is an immensely powerful, naturally occurring nuclear fusion reactor. If you added up all the energy we produce in one year from nuclear reactors, wind turbines, and burning carbon together it would equal the sunlight energy hitting the earth in a single hour.

Every day, deep within the sun’s core intense nuclear activity generates a colossal amount of radiation. This radiation generates light energy particles called photons. While they have no physical mass of their own, these photons are bursting with a tremendous amount of energy and momentum.

It can take one million years for a photon to push out from the core to the surface of the sun. Once they reach the surface these photons flash through space at speeds of up to 670 million miles per hour. They reach earth and any surface including solar panels in around eight minutes.

Photons and energy

Sunlight energy hits the earth’s surface in the form of photons. Not all of them reach the surface, however. Some are absorbed by the earth’s atmosphere. The atmosphere plays an important role in filtering how many photons we receive.

Photons have different wavelengths. Longer wavelengths have less energy and shorter wavelengths have more. Photons without enough energy can’t be seen. These are what make up infrared light. Similarly, we can’t see photons with too much energy. These are what make up ultraviolet light.

Also, check out our post titled “Do Solar Panels Use Heat or Light?“

What Type of Light Do Solar Panels Need?

Solar panels generate the most energy from visible light. Infrared has too little energy to spark the process that produces an electric current. Ultraviolet wavelengths have too much energy. UV wavelengths create heat and reduce solar panels’ efficiency.

How does light generate electricity in a solar panel?

One of three things happens when a photon reaches a solar cell. It will be reflected by the cell, absorbed by it or it will go through the cell. Only when it is absorbed by the cell will an electric current be generated.

Solar panels are made from two layers of silicon. Silicon is a semiconducting material which means it allows electricity to flow through it. (Source)

Can you get solar energy in low light?

In total darkness, a solar panel will not produce any electricity. As it gets lighter, however, the current in a solar panel increases until it reaches a point where any additional light does not create additional current.

On cloudy days solar panels can still generate electricity although at a much lower rate. This is because there is a lower incidence of light. There is still light, just not as much light as there is on a day with full sunshine.

Solar energy and artificial light

Solar works best with natural light. This is not to say that solar does not work with artificial light. Solar panels can work with artificial light but it is not as efficient in generating electricity as sunlight is.

Artificial light such as incandescent and fluorescent bulbs mimic the solar spectrum of the sun. Even lasers and neon lamps can produce energy although at a much lower rate. Light bulbs represent the best option for producing solar energy from artificial sources.

LED lights produce the most energy in a solar panel from an artificial light source. Incandescent lights produce less and have the added disadvantage of producing more heat as a by-product. Heat reduces the efficiency of a solar panel.

The ability to generate solar from artificial light sources gives the option to use solar panels indoors or even in a moving vehicle like an RV or a motorhome.

Do Solar Panels at Work at Night?

For the most part, solar panels will not produce electricity at night. There is however ongoing research into solar panels that will allow us to generate electricity at night.

This concept would prove groundbreaking if successful. The concept was invented by Carvey Maigue, an electrical engineering student. Called the AuREUS or Aurora Renewable Energy and UV Sequestration it is a two-step process. (Source)

First, a combination of organic luminescent particles absorbs UV light and converts it to visible light. A solar film then converts that visible light into energy. It absorbs UV light and emits visible light just like how we breathe in oxygen and breathe out carbon dioxide.

Produced in a form similar to what’s used for bulletproof glass, this light-harvesting technology can be used to make windows, walls, or any other building exterior.