Who Invented the Solar Panel?

The solar energy industry is growing at the second fastest rate in the world out of all the renewable resources and provides millions of people with power. Today, you see solar panels on your daily drive to the grocery store, through national parks, and even on space stations and satellites. But who invented the solar panel that is driving the renewable energy movement?

The basis of modern solar panels was invented by Charles Fritts in 1883 in New York City. However, without the discovery of the photovoltaic effect by Alexandre Edmond Becquerel and the development of the solar cell by Richard Evans Day and William Grylls Adams, the solar panel we know may not have been developed.

In this article, we will explore the beginnings of solar cell, solar panels, and the photovoltaic effect.

What is the photovoltaic effect, and who discovered it?

Before we get into Charles Fritts’s story, we have to shed some light on the photovoltaic effect. This was a phenomenon discovered in 1839 by Alexandre Edmond Becquerel, a French physicist.  At 19 years old, he exposed an electrode to different types of light and discovered that under the correct conditions, sunlight could generate a current and voltage.

The photovoltaic effect generates energy when light strikes electrons, allowing them to move. Usually, electrons stay dormant inside atoms within a crystal. What Becquerel discovered, though, is if you layer negatively-charge electrons in positively-charged spaces, the electrons will move when exposed to light. Instead of sitting still, these electrons will wander into the positively-charged spaces to create an electric current.

In 1848, another massive discovery in the development of solar technology was discovered by Willoughby Smith. He found that the element selenium could carry photoconductivity. After further testing, he realized that the selenium rods produce electrical currents only when exposed to sunlight.

In 1877, William Grylls Adams and Richard Evans Day took the information discovered by Becquerel and Smith to create their version of a solar cell. They discovered the selenium used by Smith almost 30 years before could convert light into an electric current without heat and without moving parts.

Though Adams and Day’s discovery did create enough electricity to power even the most basic electrical equipment, their discovery paved the way for the modern-day solar cell. They wrote an article together called “The Action of Light on Selenium.”

Without the ingenuity of these four men, the solar panel we know would not have been made. However, it took several iterations, patents, and further experiments to create a useful solar cell.

Charles Fritts’s first solar cell

Charles Fritts was an inventor, given license to work and live in a building in New York City. In 1833, Inspired by knowledge passed on by Becquerel, Adams, and Day, he coated a selenium semiconductor with a layer of gold and a layer of brass and placed them in a glass box. As sunlight shone through the glass, a significant electric current was produced.

Fritts realized that the photons in selenium had enough energy to toss electrons from their atoms. He found that by attaching wires to the selenium semiconductor, the electrons would flow through them when exposed to sunlight.

On this day, Fritts created the first modern solar cell, one that he thought had huge potential. Though this solar cell only converted 1-2% of sunlight into energy, Fritts believed this was a significant amount of electricity, one that he thought would compete with Thomas Edison’s inventions. However, the material used, especially selenium and gold, was unaffordable at the time.

Unfortunately for Fritts, this was around the same time that coal power plants were created, and the low conversion rate did not set the consumer world on fire. Though many patents were produced inspired by Fritts’s device, it would still take several decades before a more practical invention was created, and over a century before solar panels became consumer products.

Fritts’s invention, though, did have other applications outside of its energy production potential. His selenium cells were used to create light sensors for cameras, which would time exposures. Additionally, the selenium cells were used to power satellites, as the technology was affordable to space programs.

Modern-day solar panels

In the 1950s, Daryl Chapin, Calvin Fuller, and Gerald Pearson were working to create a more efficient solar cell for Bell Laboratories. They found that using thin strips of silicon instead of gold and selenium would generate far more electricity than Fritss’s, converting six percent of sunlight, which was a similar efficiency to a gasoline engine. Though this was the first practical solar cell, affordability was still an issue.

At this point in history, solar’s popularity ebbed and flowed based on the affordability of traditional energy sources. Coal, gas, and now nuclear power were the main ways the world produced electricity, and although solar panels’ conversion rate continued to improve, producing silicon for solar cells was too expensive and deemed unnecessary.

Despite this technology’s price tag, NASA incorporated silicon solar cells in their satellite Vanguard I. This satellite was equipped with a panel containing 108 solar cells, giving it an efficiency of up to 10%, and it is still orbiting the Earth today. Space exploration was one of the major benefactors of solar panels, as they were one of the only industries that could afford and practically use solar power.

In 2022, technological advances have improved silicon cells to up to 24% efficiency, and everyday solar technology improves. Additionally, the manufacturing of solar panels, batteries, and everything needed to set up devices in homes and businesses constantly becomes more affordable. Now, solar technology produces enough electricity to power 23 million homes, and the market grows at 33% a year.

Conclusion

Though Fritts’s invention in 1833 took almost 200 years, it is now one of the leading sources of renewable energy.  The inventions and discoveries by Becquerel, Smith, Adams, and Day led to a power source big enough to support a space station and accessible enough to power individual homes.