Transcript Solar Energy - Hisar School Blogs

Solar Energy
Damla Aydoğan
Ömer Kamber
What is solar energy?
• Solar energy is radiant light and heat from the sun harnessed using a range of
ever-evolving technologies such as solar heating, solar photovoltaics, solar
thermal energy, solar architecture and artificial photosynthesis.
• Solar energy is lauded as an inexhaustible fuel source that is pollution and often
noise free. The technology is also versatile. For example, solar cells generate
energy for far-out places like satellites in Earth orbit and cabins deep in the
Rocky Mountains as easily as they can power downtown buildings and futuristic
cars.
• But solar energy doesn't work at night without a storage device such as a
battery, and cloudy weather can make the technology unreliable during the day.
Solar technologies are also very expensive and require a lot of land area to
collect the sun's energy at rates useful to lots of people.
• Despite the drawbacks, solar energy use has surged at about 20 percent a year
over the past 15 years, thanks to rapidly falling prices and gains in efficiency.
Japan, Germany, and the United States are major markets for solar cells. With
tax incentives, solar electricity can often pay for itself in five to ten years.
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History
• We can trace all energy used on our planet back to the source...the
nearest star, our sun. The history of solar energy is as old as
humankind. In the last two centuries, we started using Sun's energy
directly to make electricity.
• In 1839, Alexandre Edmond Becquerel discovered that certain
materials produced small amounts of electric current when exposed
to light.
• William Grylls Adams, who, with his student, Richard Evans Day,
discovered in 1876 that a solid material - selenium - produced
electricity when exposed to light. Selenium photovoltaic cells were
converting light to electricity at 1 to 2 percent efficiency.
• Photovoltaic, or PV for short, is the word that describes converting
sunlight into electricity: photo, meaning pertaining to light,
and voltaic meaning producing voltage. It took, more than 100 years,
however, for the concept of electricity from sunlight to become
more than an just an experiment.
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Benefits
• If you like the thought of contributing to the efforts of making the
earth a better place to live, or if you like money, you’ll love solar
energy. There are a myriad of great reasons to install a photovoltaic
solar power generation system in your home or commercial
building, here are a few.
• A solar energy system adds to your property value without adding
any tax liability.
• Home based solar power is a quiet, nearly maintenance free,
continuous source of electricity.
• Solar electric systems reduce pollution and CO2 emissions by
generating electrical power using radiant Sun light that can replace
electricity that comes from coal fired electrical plants.
• Many states including California, Massachusetts, New Jersey,
Maryland, Texas and Arizona offer $0 down installation plans that
immediately lower your electric bill and cost nothing to install or
maintain.
Drawbacks
• Inefficiency : Since not all the light from the sun is absorbed
by the solar panels therefore most solar panels have a 40%
efficiency rate which means 60% of the sunlight gets wasted
and is not harnessed. New emerging technologies however
have increased the rate of efficiency of solar panels from 40 to
80% and on the downside have increased the cost of solar
panels as well.
• . Reliability : Unlike other renewable source which can also be
operated during night, solar panels prove to be useless during
night which means you have to depend on the local utility grid
to draw power in the night. Else you can buy solar batteries to
store excess power which you can later utilize in the night.