How Does a Solar Panel Work?

You can thank Albert Einstein for solar power, one of the leading edges of the clean energy revolution. He won his Nobel Prize in physics not for his theories of relativity, but for explaining the photoelectric effect.

The confusing fact that certain metals would spontaneously produce an electric current when exposed to rays of light was cleared up when Einstein pointed out that visible and invisible light is made up of individual photons. He explained that this energy could be imparted to the electrons surrounding atoms of conducting metals, knocking them free and producing an electric current — the energy of flowing electrons — as a result.

Today’s photovoltaic solar panels operate on that same principle. A single photovoltaic cell is typically made out of two layers of silicon peppered with different kinds of elements capable of easily giving up electrons.

A silicon laced with metal phosphorous atoms is a common option for the negatively-charged layer — the one with extra electrons, provided by said phosphorous atoms, or rather ions. Boron is a common extra ingredient in the positive layer — meaning that boron atoms are shy of electrons, and therefore slightly positive.

Many of these cells are strung together to produce a panel, and today’s most advanced cells are incredibly light and far thinner than a human hair.

With loose, ready-to-flow electrons at the ready, all that’s required is an energy source to push them along through the material, producing current flow through a circuit that can be used as an electric power source for the energy grid.

The energy comes from solar radiation, in which individual photons of light literally strike the ions and push their electrons along. This happens in much the same way as when molecules of water strike a mill and cause it to turn — or when air molecules on a windy day strike the blades of wind turbine, forcing it to rotate.

The major difference between photovoltaic solar panels and mechanical generators like wind turbines is that the energy source is directly translated into electricity.

The kinetic energy of blowing wind turns the blades of a turbine, and the spinning of the turbine’s magnets produces an electrical current. There is no intermediary form of energy with photovoltaic solar energy, as the energy of the sun is immediately converted into the energy of moving electrons. In addition, there are no moving parts to wear out, so photovoltaics can last a long time under the right conditions.

That said, there are other methods of capturing solar power that involve extra steps, including capturing solar energy in the form of heat. This occurs when the sun’s rays warm a darkly-painted tank filled with water and then uses temperature differences between specific kinds of materials to coax spontaneous electric currents.

There are advantages and disadvantages to each technology for capturing solar energy, and the best option will vary based on environmental factors, as well as the logistics and needs of the energy grid.

Solar energy is most effective in areas that receive large amounts of direct sunlight, and it’s impacted by cloud cover and latitude — the angle at which the sun’s rays strike the Earth at various distances from the equator affects the energy per square unit.

That said, as solar cell technology advances to become cheaper and more versatile, it’s increasingly used in multipurpose building surfaces, including roofs. It may not be long before virtually all roof shingles simultaneously serve as building material and energy grid components by default.

Solar cell system diagram.

Photo Credit: Getty Images

For most individual homeowners, solar power remains one of the few energy sources a person can capture without any additional infrastructure provided by power companies or government, making it an increasingly popular choice for the independent-minded.

This may be why more than half of all new electric power sources in the U.S. in 2018 have been solar so far. Solar power makes up less than two percent of American energy currently, but as the fastest growing energy source for several years running, it could eventually surpass any other category you care to name.

Photo credit: Getty Images

67 comments

Gino C
Past Member 1 months ago

thanks

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Caitlin L
Caitlin L1 months ago

thanks very much

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hELEN hEARFIELD
hELEN h1 months ago

tyfs

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Peggy B
Peggy B1 months ago

TY

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Latoya B
Latoya Brookins2 months ago

I need to know these things in case of a zombie apocalypse.

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John W
John W2 months ago

It is amazing how much this technology has advanced in my lifetime :-)

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John W
John W2 months ago

TYFST

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Chad Anderson
Chad A2 months ago

Thank you.

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rachel r
Past Member 2 months ago

Thank you!

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heather g
heather g2 months ago

One can find on-line instructions of how to make a solar panel. And they work!
I commented on this before and my post was deleted ????

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