The sun has been a constant presence in the life of human beings ever since human beings have existed. Oeople have feared the Sun, worshipped the Sun, paid tribute to the Sun, and sought guidance from the Sun. We have used it for navigation, to cook our food, and for our daily chores. Humans have been harnessing the power of the sun for centuries, and the invention of solar panels is a continuation of that movement, just with a technological touch.
Today, solar panels are more efficient than they have ever been, and their development has been a steady process of iteration and improvement. The solar installations in Los Angeles, Miami, all over America, and the world, are a result of years of dedicated work by scientists who have continued the instinctual human trend of using the energy of the sun to improve the lives of human beings.
The First Use of Solar Energy
Humans have used the sun’s energy as early as 700 BC when people learned how to use glass magnifying materials to create fire. In the third century BC, the Romans and Greeks used mirrors to light torches for their religious ceremonies. These mirrors were called burning mirrors, and there is a famous story of the Greek mathematician, Archimedes, using a burning mirror to set fire to the invading Roman fleet of Marcus Claudius Marcellus in 212 BC. That story is likely apocryphal, but even if it is not true, it does show how much ancient people respected the power of the sun.
In the 1700’s, solar energy was used for more practical purposes with solar ovens, which used sunlight to heat and cook food. However, it was not until a century later that the use of sunlight to generate electricity was discovered.
The First Solar Panels
The photovoltaic effect is the generation of electricity using light, and it was first observed by the French scientist, Alexandre-Edmond Becquerel in 1839. He conducted an experiment where he placed silver chloride in an acidic solution, which was illuminated while connected to platinum electrodes. The result was that voltage and current were generated, providing the very first example of the technology that would be later used in all solar panels.
A few years later, in 1873, Willoughby Smith discovered that selenium had photoconductive properties. Just four years later, William Grylls Adams and Richards Evans Day discovered that selenium generated electricity when exposed to sunlight. However, the first actual solar cell was credited to Charles Fritts. In 1883, he coated selenium with a thin layer of gold, this first example of a solar cell successfully produced electricity, though at an efficiency level of less than 1%. Various developments in the implementation of photovoltaic technology followed through the years, but the biggest breakthrough came in 1954.
In that year, Calvin Fuller, Daryl Chapin, and Gerald Pearson created the first silicon photovoltaic cell; silicon is the material used in all modern solar panels, so they are credited with the creation of modern PV technology. That is because their cell could provide power to a toy ferris wheel and a transistor radio for several hours. Their impressive accomplishment makes them part of the continuum of people who discovered that the sun’s light has more power than most people realize.
The Future of Solar Panels
The use of solar energy goes back for centuries, but where does it go next? Chances are that solar panels will follow the trend of all electronics and get smaller and more efficient, though at the moment, efficiency is the main concern. The first silicon solar cell had an efficiency rating of about 6%, commercial cells can achieve 18% to 22% efficiency; lab experiments have reached efficiency ratings as high as 40%. Clearly solar power has come a long way since it was first used for making fire, but looking at all that has been achieved since then, solar power still has a long way to go.