Who invented solar panels?
Solar energy is actually nothing new. People have used solar power as far back in history as the 7th century B.C. In its most primitive state, energy from the sun has been revered and put to use almost as long as man has walked the earth.
The earliest uses of solar power included focusing the sun’s energy through a magnifying glass to start fires for cooking. By the 3rd century B.C., Greeks and Romans bounced sunlight off of “burning mirrors” to light sacred torches for religious ceremonies.
Sunrooms were invented in ancient times to capture solar energy for its natural warmth. These usually south-facing rooms have captured and concentrated sunlight from the famous Roman bathhouses to Native American adobes, and are still popular today in many modern homes.
One legend in Greek solar history is of the scientist Archimedes setting fire to besieging wooden ships from the Roman Empire. The story goes that he reflected the sun’s light energy off of bronze shields, concentrating the rays and attacking the enemy before they made landfall.
Think of it as a kind of ancient solar laser beam. Whether this actually happened in Archimedes’ time or not is unverified. But this experiment in solar power was tested by the Greek navy in the 1970s. They did set fire to a wooden test ship 50 meters away using nothing but the legendary bronze shield and the solar light energy.1
Solar power cell technology invented
In 1839, French physicist Edmond Becquerel discovered the photovoltaic effect while experimenting with a cell made of metal electrodes in a conducting solution.2 He noted that the cell produced more electricity when it was exposed to light.
Later in 1873, Willoughby Smith discovered that selenium could function as a photoconductor.
Just three years later, in 1876 William Grylls Adams and Richard Evans Day applied the photovoltaic principle discovered by Becquerel to selenium. They recorded that it could, in fact, generate electricity when exposed to light.
Almost 50 years after the photovoltaic effect’s discovery, in 1883, American inventor Charles Fritz created the first working selenium solar cell.3 Though we use silicon in cells for modern solar panels, this solar cell was a major precursor to the technology used today.
In a way, many physicists played a part in solar cell invention. Becquerel is attributed with uncovering the potential of the photovoltaic effect, and Fritz with actually creating the ancestor to all solar cells.
Awareness and production of solar technology
Albert Einstein had a role to play in bringing the world’s attention to solar energy and its potential. In 1905, Einstein published a paper on the photoelectric effect and how light carries energy.4 This generated more attention and acceptance for solar power on a broader scale.
The big leap toward the solar cells like the ones used in panels today came from the work of Bell Labs in 1954. Three scientists there, Daryl Chapin, Calvin Fuller, and Gerald Pearson, created a more practical solar cell using silicon.
Advantages to silicon are better efficiency and its wide availability as a natural resource.5
As the space age developed, solar panels were used to power various parts of spacecraft throughout the late 1950s and 1960s. The first was the Vanguard I satellite in 1958, followed by Vanguard II, Explorer III, and Sputnik-3.
In 1964, NASA launched the Nimbus satellite, which ran entirely on its 470-watt photovoltaic solar panel array.6 It wouldn’t be long now until solar energy’s potential moved from outer space to homes and businesses on planet earth.
Solar panels as a viable energy alternative
In the 1970s, an oil shortage brought awareness of U.S. dependency on foreign energy resources. It was a time of high inflation when Americans were squeezed economically, and shortages in essentials made the need for further innovation glaringly evident.
It was during this time that president Jimmy Carter had solar panels installed onto the White House roof. This was a statement to make clean energy through solar more tangible for people, and to spread awareness.
Even with more people interested in solar over recent decades, cost and efficiency have slowly been improving. As solar panels are built to be more efficient and to cost less, solar has become a realistic way for everyday people to generate power for their homes and businesses.
Perhaps the most significant leaps forward for solar, in both efficiency and price, have been in the past several years.
Solar panel efficiency and price over the years
Solar cell improvements based on Becquerel’s initial uncovering of the photovoltaic effect brought early solar panels to about 1 percent efficiency and around $300 per watt. It cost about $2 – $3 per watt to generate electricity from coal at the time.7
Bell Labs’ 1954 silicon solar cells operated at around 4 percent efficiency and later achieved 11 percent efficiency. This was a significant increase that enabled powering an electric device for several hours for the first time in history.
Then in 1959, Hoffman Electronics achieved 10 percent efficiency. Soon after, they beat their own record with 14 percent efficiency in 1960.
These efficiency upgrades helped push solar panels into the space program. The use of solar panels in the space program through the 1960s increased production and slowly the price reduced to around $100 per watt.
Exxon funded Dr. Elliot Berman’s research in the 1970s, which produced a less expensive solar cell, and brought solar panel cost down to about $20 per watt.8
Currently, solar panels average between 15 and 18 percent efficiency and can cost as low as $0.50 per watt.
With the long history of solar technology, it’s notable that the real sea change for solar has been in the past few decades. Since the 1980s, the cost of solar panels has dropped 10 percent per year on average.9
These improvements in solar technology and cost reduction are thanks to scientists and engineers dedicated to solar as a leading source of clean, low-cost electricity for everyone.
Endnotes
