Today, millions of consumers around the world already have a photovoltaic solar panel installed on the roof of their homes, businesses, agro-industries and many other types of establishments.
But those who think this is a new technology are wrong.
Although it already plays an important role in the production of electricity around the world, the solar panel has a long history.
In this article, we’ll go back a few centuries and discover the roots of this technology that is transforming the world.
First uses of solar energy
Theoretically, we can say that the human race has been using the power of the sun since the 7th century BC.
As historical evidence from this period shows, humans used glass materials as a magnifying glass to focus sunlight and thus make fire.
As early as the 3rd century BC, the Romans and Greeks used mirrors for the same purpose, but to light torches in religious ceremonies.
These became known as “burning mirrors” and were also used by the Chinese, according to documents dating back to AD 20.
Another ancient way to use solar energy, which is still in use today, is the construction of “solar rooms” in buildings that use giant windows to concentrate sunlight into a single point.
Some of the best-known Roman baths, especially those facing south, were solar rooms.
This same use of solar energy was used by the ancestors of the ancient Anasazi people in 1200 AD in North America.
In winter, they settle in south-facing houses on the cliffs to capture the light and heat of the sun.
Much later, between the 17th and 18th centuries, scientists were able to capture sunlight to power portable ovens on long journeys.
They also used it to produce solar powered steamboats.
We can therefore see that even before its popularization thanks to photovoltaic solar panels, solar energy was already used in different ways, being a common practice in our civilization.
The invention of the photovoltaic solar panel
You could say that the invention of the photovoltaic solar panel was a collective work, the result of various investigations and discoveries by various scientists.
There is some debate about the exact date and its inventor, but most attribute the appearance of the technology to French scientist Edmond Becquerel.
Becquerel discovered the photovoltaic effect for the first time, in 1839, while conducting electrochemical experiments in his father’s workshop.
The photovoltaic effect consists of the appearance of an electric voltage in a semiconductor material due to the release of electrons from its surface when it is exposed to the radiation of light photons.
The process is the key to how the technology works and contributed to the emergence of the first Selenium photovoltaic cells.
In 1873, the British electrical engineer Willoughby Smith discovered that selenium had a photoconductive property.
This paved the way for scientists William Grylls Adams and Richard Evans Day to discover in 1876 that this element generates electricity when exposed to sunlight.
Soon after, in 1883, inventor Charles Fritts succeeded in producing the first solar cell made from layers of selenium, which is why some attribute the invention of the solar cell to him.
However, the vast majority of photovoltaic panels in use today are made with silicon photovoltaic cells.
That’s why part of the scientific community attributes the invention of the solar cell to scientists Daryl Chapin, Calvin Fuller, and Gerald Pearson, who first produced a silicon solar cell at the Bell Lab in 1954.
It was the first time that photovoltaic technology could power an electrical device for several hours a day.
Although it had a light-to-electricity conversion efficiency of only 4%, less than a quarter of the efficiency of a modern photovoltaic panel.
Highlights in the history of photovoltaic panels
Photovoltaic solar panel in space:
Some of the earliest uses of solar panels were in space.
The first took place in 1958, when the Vanguard I satellite was launched on its space travel with a small 1W panel to power its radio.
That same year, the Vanguard II, Explorer III and Sputnik-3 satellites were also launched with solar panels into space.
In 1964 and 1966, NASA was responsible for launching the first 100% solar satellite and space station, generated by photovoltaic panels, producing 470 W and 1 kW respectively.
First house with a photovoltaic solar panel:
Already in 1973, the first solar-powered house was built, manufactured by the University of Delaware, USA.
Called “Solar One” (First Solar), the project used a hybrid of solar thermal and photovoltaic energy.
It was also the first use of BIPV (Building Integrated Photovoltaics).
In other words, the house didn’t have solar panels, but photovoltaic technology was built into its roof, similar to Tesla’s solar tiles.
Evolution of efficiency in electrical conversion
Between 1957 and 1960, Hoffman Eletronics managed to break several photovoltaic efficiency records, dropping from 8% to 14%.
In 1985, another significant achievement was achieved by the University of South Wales, USA, which achieved 20% efficiency with silicon solar cells.
In 1999, a joint investigation between the National Renewable Energy Laboratory and Spectrolab Inc. achieved a yield of 33.3%.
The record was again broken by the University of South Wales in 2016, when it reached an efficiency of 34.5%.
Solar powered airplane
In 1981, the first solar-powered aircraft, the Solar Challenger, crossed the Channel between France and the United Kingdom, piloted by its inventor, Paul MacCready.
Seventeen years later, the “Pathfinder” solar drone sets the altitude record after reaching an altitude of nearly 25,000 km.
Shortly after, this record was broken by NASA in 2001 when its plane reached an altitude of nearly 30,000 km.
In 2016, Bertrand Piccard was responsible for the first round-the-world trip aboard today’s largest solar aircraft, the Solar Impulse 2.
In the United States in 1979, President-elect Jimmy Carter ordered the installation of solar panels to power the White House during his tenure.
When Ronald Reagan took office in 1981, he ordered the removal of these photovoltaic panels.
Almost 30 years later, in 2010, President Barack Obama reinstalled photovoltaic solar panels during his first term, as well as a solar heating system.
Evolution of the price of solar energy
The prices of photovoltaic solar panels have fallen considerably over the past decades.
This has contributed to an increase in demand and the installation of millions of systems around the world.
In 1956 the cost of the panels was $ 300 per watt, in 1975 that figure had fallen to just over $ 100 per watt.
In 1998, a panel could cost around $ 0.50 per watt.
In other words, we can say that the cost of photovoltaic panels has depreciated by 10% per year since 1980.
In summary, we can see that this was, and continues to be, responsible for the growing popularity of photovoltaic solar panels and the establishment of solar power as a clean and safe source of energy for the world of. today and tomorrow.