Solar power is not just limited to rooftop solar panels. Anything powered by the sun is called solar power. This brief article will walk you through the history of solar energy.
Early Days
It all began in the 7th century BCE when humans used the sun to create fires. Clear pieces of glass were held over dry wood. This concentrated sunlight onto a single area to light a fire.
After a few decades, the Greeks and Romans invented mirrors that could use solar power to light torches for ceremonies. These "burning mirrors" became popular and spread to China in 20 CE.
Solar energy is not limited to lighting fires; humans throughout history have used it to keep themselves warm. You'll find "sunrooms" in many cultures over a long time. These rooms had huge windows to concentrate sunlight onto a certain spot.
A few Roman bathhouses had sunrooms in which the windows faced south. In the American Southwest, the Anasazi built houses on cliffs that faced south to help warm their homes during the winter.
In the 1800s, solar-powered steamboats were being used for water travel. On December 1, 1870, Captain Ericsson tried using sunlight to generate power. This discovery didn’t mean to replace traditional steamboats and was reserved for areas with increased sunshine.
The Science
If humanity hadn’t learned to harness the sun's energy, we wouldn’t see the amazing technologies today, including solar panels. Countless projects, research studies, and people have contributed to the solar industry and the invention of solar panels.
Everyone should know two things about the history of solar power and its technology: the photovoltaic and the photoelectric effect. They are the fundamentals of solar power.
Photovoltaic Effect
This happens when light falls upon anything. Electrons absorb this light energy in that material, achieving a higher energy level and becoming excited. This generates an electric current. The electrons flow inside the material (electricity) but are not ejected out of it.
Photoelectric Effect
This is similar to the photovoltaic effect. When anything is exposed to electromagnetic radiation like light, it causes the electrons present in the material to be ejected.
Like the photovoltaic effect, electrons absorb the incoming light energy, which is transformed into kinetic energy. With this increased energy, the electrons escape the material and are ejected.
The History Of Solar Technology
Advancements in solar power were only made possible by the discovery of the photovoltaic and photoelectric effects, which only furthered our understanding of solar power. The timeline below will showcase a brief history of solar power and the scientists that contributed to it:
1839:
Alexandre-Edmond Becquerel, a French scientist, invented the photovoltaic cell.
1873:
The discovery of the photovoltaic effect in selenium by Willoughby Smith.
1883:
- The development of a solar cell using selenium coated with gold by Charles Fritts.
- John Ericsson created a “sun motor” to run steam boilers.
1884:
The installation of solar panels on a New York City rooftop by Charles Fritts.
1888:
The Hallwachs Effect was put forward by Wilhelm Hallwachs, which described the physics of photovoltaic cells.
1905:
Albert Einstein explained the generation of electricity from light.
Advances In Solar Energy Technology
With the history of solar energy pushing us forward, we enter the 20th and 21st centuries, in which further advancements refined the technology and are doing so to this day:
1912:
The Sun Power Company built the world's first solar thermal power plant.
1916:
Single crystals made from metal by Jan Czochralski were the base for semiconductor wafers in electronics like solar cells.
1941:
Russel Ohl, an engineer at Bell Laboratories, created the first monocrystalline silicon solar cell.
1951:
The first solar cells were made from germanium.
1954:
Bell Labs created the first solar panel from silicon.
1947:
Solar homes became popular due to the energy shortage after World War II.
1955-1960:
- The first solar-powered telephone call was made.
- The first solar-powered radio was introduced.
- Vanguard I became the first spacecraft powered by solar technology.
1960:
Photovoltaics improved in efficiency from 8% to 14%.
1962:
Telstar, the first solar-powered communications satellite, was run by 3,600 cells from Bell Laboratories.
1967:
Soyuz 1, launched by the USSR, was the first solar-powered spacecraft to carry humans.
1972:
Solar-powered watches entered the market.
1981:
The Solar Challenger was the world's first solar aircraft capable of covering long distances.
1982:
The first large-scale solar farm was built in California.
1985:
- Lithium-ion batteries were developed.
- Silicon cells reached 20% efficiency.
1991:
Lithium-ion batteries started commercial production.
1999:
Solar cells reached 32% efficiency.
2005:
The Federal Investment Tax Credit (ITC) was created.
2008:
NREL set a world record for achieving 40.8% solar cell efficiency.
2015:
- The Powerwall battery pack released by Tesla allowed solar battery storage to store electricity.
- Project Sunroof, released by Google, was designed to assist homeowners in deciding the feasibility of rooftop home solar for their homes.
2020:
- Experts calculated that it’s more expensive to operate an existing coal plant than to build a new solar plant.
- In California, all newly built homes needed to include solar panels.
Solar Energy
Solar energy seems like a new discovery, but it’s not the case. It has been in use since the dawn of humanity when it was used to light fires by focusing sunlight on only a small spot. The history of solar energy is also a remarkable journey of human creativity across millennia.
Significant discoveries in the 19th century, like photovoltaic and photoelectric effects, initiated the renewable energy race by which solar panels were created and are being improved in efficiency to this day. You can expect to see even better inventions in the next hundred years.