The history of solar power
in terms of photovoltaics is much more recent, and humans have only
known about the principle of photovoltaics since the mid 1800’s.
However, solar energy history in general dates back to at least the 3rd
Century B.C., and probably even before this.
History of Solar Thermal
The first recorded use of
solar thermal energy was around the 4rd Century B.C., when the Ancient
Greeks used mirrors to concentrate the sun’s rays onto a focal point to
light fires and torches for religious ceremonies. The Romans also used
this same technology, although many believe that this was merely
another one of the ideas that they borrowed from the Greeks.
In the middle of the 2nd
Century B.C., the Greek scientist Archimedes was said to have used a
huge array of bronze shields to redirect the sunlight onto a focal
point, thus setting on fire the ships of Greece's enemies. The Greek
Navy successfully recreated this feat in 1973.
The Greeks were also known
to use what are commonly called solar
tubes or solar skylights to allow
light and heat into their homes. These devices usually contain mirrors
inside them to redirect the sun’s rays into the home. They are still
quite commonly used today, and the design essentially hasn’t changed
since the time of the Greeks.
The first recorded use of
solar energy in China occurred around 20 A.D. when the Chinese used the
same principles as the Greeks to light fires using mirrors to
concentrate the sun’s energy. It’s not known whether they came up with
this idea independently, although most believe that they did and
possible knew about it for centuries before.
History of Solar Energy
for Heating Purposes
It is known that the
Romans used gigantic windows in their bathhouses to heat the buildings
and the baths themselves as early as the 1st Century A.D.
extremely common for houses in Ancient Rome to have sunrooms which they
used to help heat their homes, and by the 6th Century they even had
laws that guaranteed houses sun rights so they could have an
unobstructed view of the sun to heat their homes.
The Native Americans were
also known to use the sun to help heat up their dwellings. Some tribes,
such as the Anasazi lived in south facing caves to help capture the
sunlight to heat their homes in the winter. Other tribes, especially
the nomadic ones, also placed the entrances to their teepees and tents
to the south for the same purpose.
Photovoltaic Solar Energy
French scientist Edmond
Becquerel was the first person to discover the photovoltaic effect in
1839. While doing an experiment on electricity conduction, he
discovered that certain materials conducted more electricity when they
were exposed to light. However, his findings were not taken seriously
or given much credit and the idea was basically forgotten about for
another thirty years.
In 1873, English
electrical engineer Willoughby Smith discovered that Selenium was
photoconductive and produced a small amount of electricity when exposed
to light. This lead others to start researching the topic and
their own selenium solar cells, although none of these proved to
produce enough electricity to do anything yet.
In 1905, Albert Einstein
wrote and published a paper describing his theory on the photoelectric
effect. He would later win the Nobel Prize in 1921 for these theories.
However, this was only after they had been proven to be true by
American physicist Robert A. Milliken in 1916. Milliken himself was
also a Nobel Laureate for his work in the field of photoelectrics.
It wasn’t until silicon
started being used that solar panels became efficient enough to be a
viable means of generating electricity. The first silicon solar cell
was created at Bell Telephone Laboratories in 1954. This first silicon
PV solar cell had an efficiency of around only 4%, although they were
able to create a cell with around 11% efficiency many
In the mid 1950’s, solar
panels were developed that could be used on spacecrafts and satellites.
This would lead to Vanguard 1 being the first satellite containing PV
solar panels to be launched in 1958. The Vanguard 1 had an array of
very small solar panels which generated enough electricity to keep its
radios powered. Several other satellites with PV solar panels onboard
were also sent into space that year, and this was the first major
commercial use of solar panels, as they had yet to take hold anywhere
The 1960’s saw a lot of
research and money being put into developing more efficient solar
panels. Many Japanese companies started producing cheaper, higher
efficiency cells, and many of these companies are still leaders in the
market today. Recent developments include thin film solar panels which
are even cheaper to produce and more efficient. There has also been
much research into using nanoparticles,
which could further increase
the effectiveness of photovoltaic solar panels.
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