I have a very distinct memory of tv telling
me, "every hour the sun beams enough solar
energy to power our planet for a year."
Solar power, however, has yet to deliver on
this promise from my children's television.
Why is it so hard????
The sun shines on us every day, it comes down
here we gather it up and we use it for energy
-- boom boom boom, done!
But it's slightly more complicated than that,
as you know.
In 1873, electrical engineer Willoughby Smith
discovered the element selenium was photoconductive
-- when exposed to sunlight the metallic form
of selenium becomes a semiconductor!
Three years later, other scientists discovered
selenium could be used to create electricity
from sunlight -- dubbed the photoelectric
effect.
When sunlight hits a metal like selenium the
electromagnetic radiation is absorbed into
it -- this fueled a whole HOST of physics
nerds who are still arguing whether light
is a particle or a wave to this day!
It was such a big deal the 1921 Nobel Prize
in physics was awarded to Albert Einstein
for explaining the photoelectric effect, and
for his contributions to theoretical physics…
or whatever.
Eventually, scientists discovered that the
light energy causes the freeing of electrons
which, if captured, could be used to generate
electricity!.
This photoelectric effect has since been cultivated
and researched and cultivated again, and the
discovery that many different elements display
a photoelectric effect opened it up for use
in a number of inventions!
Photosensitive cells are used in televisions,
industrial processes, telecommunications,
fiber optics, copy machines, spectroscopy
and telescopy, and to sense pollution or emphasize
other lights like in night vision or infrared
cameras; plus, of course, solar panels via
a photovoltaic cell.
Photovoltaics were invented in the 1950s,
and were popularized by the space program
as a way to power satellites.
In the 1970s, pushes were made to modernize
photovoltaics for use in commercial and residential
power -- but consumers mainly used them for
calculators, watches, radios and the like.
Like a battery, a photovoltaic cell has a
positive and negative to guide the electrons
into the system.
Each cell uses a pair of silicon wafers -- one
doped with phosphorous (negative) and one
with boron (positive).
From 1995 to 2010 solar energy use grew 20
percent a year -- and now, new inventions
are making it even more affordable.
Firstly, in 2009, China created way more solar
panels than the market needed, and the price
collapsed.
And secondly, state and federal governments
in the United States, Germany, the United
Kingdom and Japan are all giving subsidies
to cultivate better renewable energy systems.
This means more supply and demand for this
technology, and as money flows through renewables,
they get better!
Recently the University of Queen Mary in London
revealed they can turn shrimp shells into
cheap solar panels.
The shells of crustaceans contain chitin and
chitosan which can be extracted into CQD or
carbon quantum dots -- CQD solar cells aren't
new, but usually use expensive ruthenium for
its photoelectric properties.
Instead, the researchers found this biomass
byproduct of the shrimp industry can be used
to extract CQDs and create fully renewable,
cheap solar cells!
Pretty cool, huh?
Fortunately solar cells aren't the only place
finding greener solutions for energy use -- Toyota
is, too!
The new Toyota Mirai is looking to the future
with sustainability in mind; fueled by hydrogen
and leaving zero emissions behind.
Every year renewable energy is getting better,
but it's not yet as efficient as we'd hope.
For more on the efficiency of the most common
types of energy production, check out my video
about that here
What do YOU think is the most promising type
of energy?
Solar?
Wind?
Nuclear?
Or plain old coal, oil and gas?
Why?
Tell me your thoughts in the comments, and
thanks for watching.
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