How does solar energy work?
Outside of the three scenarios above, solar energy usually requires a little human input to
really work (photosynthesis, which helps grow crops for food and fuel, is a notable exception).
This help can come in lots of different forms, from architecture and urban planning, which uses
techniques to maximize light and heat from the sun to our benefit in our buildings, to solar
thermal, the most widely used category of solar energy technology, including solar cooking,
water distillation and purification and lots more, to heating water for our use and desalination.
Photo credit: Getty Images
But, by far, solar energy's most talked-about use is electricity generation. For now, photovoltaic
(PV) cells and panels remain the most-used method for turning sun into electricity. Basically,
photovoltaics cause photons from sunlight knock electrons into a higher state of energy,
creating electricity. Photovoltaic production has been doubling every two years, increasing by
an average of 48 percent each year since 2002, making it the world’s fastest-growing energy
technology.
But it's not alone in the solar world; concentrating solar systems use lenses, mirrors and
tracking systems to focus a large area of sunlight into a small, concentrated beam, which is
then used to generate electricity. This can be accomplished using a trough system; by allowing
direct sunlight to hit troughs, the solar collectors concentrate it into a single area that boils
liquid in order to make steam, which in turn moves turbines to make electricity. This up-and-
coming technology can be made even more efficient with the use of a solar tower, which is just
what it sounds like: a tower that uses careful sun tracking to concentrate solar energy near its
top. There are various other technologies that can create solar power from solar energy, but,
for now, these remain the most popular and most viable.
Outside of the three scenarios above, solar energy usually requires a little human input to
really work (photosynthesis, which helps grow crops for food and fuel, is a notable exception).
This help can come in lots of different forms, from architecture and urban planning, which uses
techniques to maximize light and heat from the sun to our benefit in our buildings, to solar
thermal, the most widely used category of solar energy technology, including solar cooking,
water distillation and purification and lots more, to heating water for our use and desalination.
Photo credit: Getty Images
But, by far, solar energy's most talked-about use is electricity generation. For now, photovoltaic
(PV) cells and panels remain the most-used method for turning sun into electricity. Basically,
photovoltaics cause photons from sunlight knock electrons into a higher state of energy,
creating electricity. Photovoltaic production has been doubling every two years, increasing by
an average of 48 percent each year since 2002, making it the world’s fastest-growing energy
technology.
But it's not alone in the solar world; concentrating solar systems use lenses, mirrors and
tracking systems to focus a large area of sunlight into a small, concentrated beam, which is
then used to generate electricity. This can be accomplished using a trough system; by allowing
direct sunlight to hit troughs, the solar collectors concentrate it into a single area that boils
liquid in order to make steam, which in turn moves turbines to make electricity. This up-and-
coming technology can be made even more efficient with the use of a solar tower, which is just
what it sounds like: a tower that uses careful sun tracking to concentrate solar energy near its
top. There are various other technologies that can create solar power from solar energy, but,
for now, these remain the most popular and most viable.
Solar Energy - How it Works:
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Alternative Energy
The Planet is Powered by the Sun
Advantages of solar energy
Solar's biggest advantage is that there's so much of it. The total solar energy available to the
earth is approximately 3850 zettajoules (ZJ) per year, while worldwide energy consumption was
0.471 ZJ in 2004, according to the US Department of Energy. Even if you aren't a solar panel
installer, you can tell that there's way more solar energy available than the world will ever need.
Solar energy is also terrifically versatile; as we mentioned above, it can be used to help grow
food and fuel, light, heat and modulate the temperatures in our homes, disinfect and desalinate
water, and more. And, once you figure out how to best maximize the available energy, solar is
the gift that keeps on giving; as long as the sun doth shine, solar energy will be available for its
myriad uses.
Disadvantages of solar energy
Solar energy's disadvantages can be pretty well boiled down to one thing: cost, at least for
using it as electricity. It takes a lot of land and costs a lot of cash to be worthwhile, as most
types of solar cells require large surface areas to achieve average efficiency, and the silicon
used in many of today's cells is also very expensive. Pollution and weather can further cut back
their efficiency, which, of course, increases the cost over time.
And though solar energy will always be available on a macro scale, it isn't always available on
an hour-to-hour scale, because it doesn't work when the sun isn't out (which always happens at
night and sometimes happen due to weather). Storing the energy in batteries for use during
these times cuts back on the efficiency further. And, of course, if you live somewhere that
doesn't have good solar energy exposure, there isn't much you can do. You gotta have the sun.
Solar's biggest advantage is that there's so much of it. The total solar energy available to the
earth is approximately 3850 zettajoules (ZJ) per year, while worldwide energy consumption was
0.471 ZJ in 2004, according to the US Department of Energy. Even if you aren't a solar panel
installer, you can tell that there's way more solar energy available than the world will ever need.
Solar energy is also terrifically versatile; as we mentioned above, it can be used to help grow
food and fuel, light, heat and modulate the temperatures in our homes, disinfect and desalinate
water, and more. And, once you figure out how to best maximize the available energy, solar is
the gift that keeps on giving; as long as the sun doth shine, solar energy will be available for its
myriad uses.
Disadvantages of solar energy
Solar energy's disadvantages can be pretty well boiled down to one thing: cost, at least for
using it as electricity. It takes a lot of land and costs a lot of cash to be worthwhile, as most
types of solar cells require large surface areas to achieve average efficiency, and the silicon
used in many of today's cells is also very expensive. Pollution and weather can further cut back
their efficiency, which, of course, increases the cost over time.
And though solar energy will always be available on a macro scale, it isn't always available on
an hour-to-hour scale, because it doesn't work when the sun isn't out (which always happens at
night and sometimes happen due to weather). Storing the energy in batteries for use during
these times cuts back on the efficiency further. And, of course, if you live somewhere that
doesn't have good solar energy exposure, there isn't much you can do. You gotta have the sun.
How Does Solar Energy Work?
by Collin Dunn, Corvallis, OR, USA on 03.27.08
SCIENCE & TECHNOLOGY
by Collin Dunn, Corvallis, OR, USA on 03.27.08
SCIENCE & TECHNOLOGY
Photo credit: Getty Images
For as long as our planet has spun 'round the sun, there's been solar energy cascading down
on the earth, and, for a long time -- since the 7th century B.C., when glass was used to magnify
it -- humans have been working to harness it. These days, technology is a bit better, providing
electricity, heating, lighting, and even flight, but the point is the same: use the sun's warm
glowing warming glow for our benefit.
Often used synonymously with solar energy, solar power is what you've got once the sun's
energy has been converted to electricity. This can be done one of two ways: heating a liquid to
produce steam and spin a generator, or through photovolatics (but that's another post). For
now, we'll concentrate on how to use the massive and largely untapped potential that exists with
solar energy. But first, some basics.
on the earth, and, for a long time -- since the 7th century B.C., when glass was used to magnify
it -- humans have been working to harness it. These days, technology is a bit better, providing
electricity, heating, lighting, and even flight, but the point is the same: use the sun's warm
glowing warming glow for our benefit.
Often used synonymously with solar energy, solar power is what you've got once the sun's
energy has been converted to electricity. This can be done one of two ways: heating a liquid to
produce steam and spin a generator, or through photovolatics (but that's another post). For
now, we'll concentrate on how to use the massive and largely untapped potential that exists with
solar energy. But first, some basics.
Photo credit: Getty Images
What is solar energy?
Short answer: the light and heat provided by the sun. A slightly longer answer: after running the
gauntlet from an average of 93 million miles away, through the various layers of atmosphere
and atmospheric conditions (clouds, pollutants, dust and the like), about half of the solar
energy is absorbed by water and land, with the other half reflected and re-radiated back into
space. The half that makes it is absorbed by oceans, land masses and plants; in the ocean, the
energy drives heat and wind-driven currents (like the Gulf Stream); on land, the energy is
absorbed and creates heat, and the little bit that's left is absorbed by plants and converted to
chemical energy through a process we all know as photosynthesis.
Short answer: the light and heat provided by the sun. A slightly longer answer: after running the
gauntlet from an average of 93 million miles away, through the various layers of atmosphere
and atmospheric conditions (clouds, pollutants, dust and the like), about half of the solar
energy is absorbed by water and land, with the other half reflected and re-radiated back into
space. The half that makes it is absorbed by oceans, land masses and plants; in the ocean, the
energy drives heat and wind-driven currents (like the Gulf Stream); on land, the energy is
absorbed and creates heat, and the little bit that's left is absorbed by plants and converted to
chemical energy through a process we all know as photosynthesis.
Photo credit: Getty Images
Photo credit: Getty Images
Photo Credit: Getty Images
Copyright 2008 Harold R Muxlow