Solar panels are changing the world, powering everything from cars and trains to blenders and homes. But did you know the solar panel was invented 140 years ago? This important green technology followed a long road before it started to transform the world.
The sun is a remarkable source of energy. In 2019, humans used about 74 trillion kilowatt hours of electricity each day, and it would take only six-and-a-half days of the sun’s energy to power our civilization for a year. Of course, that would require humans captured all the sun’s light every day. But solar panels don’t convert all the solar energy that strike them into electricity and we can’t put solar panels everywhere.
If we wanted to run the whole world on solar-generated electricity using today’s technology, we would need 23,313 square miles of solar panel “farms,” an area about the size of West Virginia. As solar panel technology gets more efficient, we’ll need less and less space to provide all the energy humans need.
Solar panels were first invented in 1883 by Charles Fritts in New York. The first panel was a layer of selenium coated by a thin layer of gold. These cells converted only one percent of the sun’s energy into electricity. In 1904, another scientist named Wilhelm Hallwachs discovered another combination: copper and cuprous oxide, but that still only converted one percent of sun power into electric power.
Charles Fritts’ basic idea is the same one that powers a solar panel today. The sun shines down on a solar panel, heating it. The heat excites electrons in silicon cells inside the solar panel, and those electrons break free and are harvested by metal plates in the panel to make direct-current (DC) electricity, like we store in batteries. DC electricity must be converted into alternating-current energy, the kind of electricity that comes from a wall socket, before we can use it to power homes and cars.
In 1954, scientists at Bell Laboratories, now known as Nokia Bell Labs, developed the first silicon cell. The inventors were Daryl Chapin, Calvin Fuller and Gerald Pearson. The silicon solar panel’s cost kept it from being practical for consumers back then. The first solar building was built at the University of Delaware in 1973, though it did not use solar panels — the whole roof was a solar converter.
The new silicon panel technology started a revolution, and today silicon panels turn between 18% and 24% of solar energy into electricity. By the end of the 2020s, it’s predicted that solar panels efficiency — the rate at which they convert sunlight into electricity — will be over 30%. If that happens, humans would need to install solar panels on only about two-thirds of the state of West Virginia to power all our needs. And, of course, solar panels will be spread out all over the world, some in solar farms and many installed on home and office buildings.
Rise of the Solar Panel
The U.S. government committed to making solar panels more accessible to the public during the energy crisis that happened when oil supplies were cut off by many countries during the 1970s.
In fact, President Jimmy Carter had 32 solar panels installed on the roof of the White House in 1979. The panels Carter used didn’t make electricity, instead they heated water to warm the White House. When traditional energy, Coal and gas, prices dropped in the 1980s, the commitment seemed to fade and Ronald Reagan, the next president, had them removed.
It took another 20 years, until 2006, for the next big national investment in solar energy. That year, the Solar Investment Tax Credit was enacted; it gave people some money back on their taxes if they installed solar panels.
Now, the race for a new source of energy was on! Over the next 10 years, the price of solar panels, which are measured by how much it costs to generate one watt of electricity, fell by 88.5 percent. Think of buying a snack for $1.00 and the next time you go back to the store it costs only 11 cents. What savings!
Burning fossil fuels like coal and oil to make electricity contributes 40% of the carbon dioxide that causes global warming. Solar panels now produce as much electricity as coal-burning power plants for just two-thirds the cost. Now that solar power is affordable, it is just a matter of time before fossil fuels are retired and the world will complete its journey to renewable energy.
Solar Energy Fun Facts
- As of 2022 there are more than 5,000 solar farms in the U.S. They generate 3.4% of the nation’s energy according to the Energy Information Agency.
- Solar energy has been used to power spacecraft, starting with the Vanguard satellite in 1958.
- Solar energy is the most plentiful source of energy, with over 173,000 terawatts hitting the earth every second. That is ten thousand times the amount of power humanity uses in a day.
- In the future, solar and wind are the two renewable energy sectors expected to create as many as 27 million new jobs by 2030.