While humanity has enjoyed the Sun and used its warmth and light since we began to exist, it wasn’t until the last few hundred years that we were able to harness the Sun’s energy for electricity.
The development of solar energy technology first began with observations, and then it became a continuous process of developing useful technology based off of these observations. One of the most important discoveries began in 1839. In a decade where the United States was only twenty-six states large and the sewing machine just began to be used, Alexandre Edmond Becquerel observed something interesting.
He noticed that some materials, when exposed to light, would produce small amounts of electric current. Becquerel experimented with this for a while, and documented his discoveries. Thirty-seven years later, William Grylls Adams and his student Richard Evans Day refined this discovery with the observation of selenium. Selenium produced energy when exposed to light, and these two men created a photovoltaic cell to harness and convert this energy into usable electricity. However, it was only a small experimental cell and not easily reproducible or cost efficient. It only produced electricity at 1-2% efficiency.
It was over 100 years later, in 1954, that solar power became a real possibility. Researchers at Bell Laboratories patented the first practical solar cell, using silicon rather than selenium. The next year, these solar cells began to be sold. Though they were only 2% efficient, compared to an average of 18% efficient today, these sold for $1,785 per watt in the equivalent of 1955 dollars.
In the 1960s and 70s, however, solar power began to be more practical. Efficiency levels grew to close to 10% with new technology, and the idea of renewable energy was becoming more and more popular. Further, space exploration was becoming a greater priority, and solar technology seemed like a useful alternative energy source for space travel. Solar-powered calculators and watches entered the scene. By the 1980s, solar power was readily available to citizens, and federal acts gave incentives and tax credits to installing renewable energy in homes. In 1983, sales of solar cells exceeded $250,000,000.
History since the 1980s has seen continuous growth of the pervasiveness and quantity of solar energy technology. Countries around the world have instituted bills and laws to help provide solar energy for their citizens, and technology is only becoming more and more efficient and refined. Further, solar is much more readily available than it was when it first began. While prices used to be $1,785 per watt, they’re now predicted to be below $1 per watt by 2020. Solar technology may have had a slow start, but it’s quickly becoming one of the most significant areas of technological advancement in our history.