Solar cells turn sunlight into electricity (Eia, 2016). They are devices
that turn the light energy to electrical energy. They consist materials where
electric current occurs, when it gets exposed by sun light. Silicon is often
used, and Norway have a good access to silicon. (Elise, 2016) Silicon has the base
number 14, and that means that they got 4 electrons in the outer shell. They,
as all the elements in the periodic system wants to fulfil the octet rule,
which means that they want to get 8 electrons in the outer shell. Silicon share
electrons with the neighbour atoms. They do this to be able to share electrons
and get 8 in the outer shell (Ungenergi, 2016).
The different solar panels have different. Some works
better than others. This means that some panels have higher efficiency. Higher
efficiency means that they can convert a higher percentage of energy from the
sun to electrical energy. Solar panels made by silicon has an efficiency of
18-20 percent. Some solar panels, made by other materials may have an
efficiency over 40 percent, in laboratory tests, but these are very expensive.
A wind turbine has an efficiency on 40-45%, and a water turbine on 90%, so solar
panels have a long way to go. The solar cells are still in development, so it
can change. (Ungenergi, 2016)
People started to use solar energy for almost a 100
years ago. At this time, they used it to produce steam for use in drive
machinery. Edmond Becquerel is the man behind the “photovoltaic effect” that
allow the conversion of sunlight to electric energy. His discovery led into the
invention of the first solar cell in 1893. Charles Fritts made this invention.
Russel Ohl ended up patent the invention that led to the first solar cell in
1956. (MrSolar, 2018)
How do we
use solar panels?
When you put many solar cells together in PV panels
you can produce energy for the whole house. (Eia, 2016) The solar panels
are made to convert sunlight (composed of particles of energy called photons)
into electricity. A solar panel consist several solar cells composed of layers
of silicon, phosphorus with negative charge and boron with positive. Most homes
have enough roof for a solar panel to produce electricity to power pall the needs.
(MrSolar, 2018) a solar panel
consist many solar cells. The panels do not generate the electricity directly,
because they heat up the water directly. The water pump pushes the cold water
from a storage tank through pipes in the solar panel. The water s heated by the
energy of the sun. they are often located at the roofs, because there they can receive
a lot of sun. (Eschool, 2017).
The panels are made by small units called solar cells.
They often come from silicon, which is a semiconductor that is the second most
abundant on planet earth. In a solar cell crystal and silicon is sandwiched
between conducted between solid layers. Each silicon atom is connected to its
neighbours by four strong bonds, which keep the electrons in place, so no
current can flow. A silicon solar cell uses two different layers of silicon. An
n-type silicon has extra electrons, and p-type silicon has extra spaces for
electrons, called holes. Where the two types pf silicon meet, electrons can
wander across the p/n junction, leaving a positive charge on one side, and
creating negative charge on the other. You can think of light as the flow of
tiny particles, called photons, shooting out from the sun. When one of these
photons strikes the silicon cell with enough energy, it can knock an electron
from its bond, leaving a hole. The negatively charged electron and location of
the positively charged hole are now free to move around. But because of the
electric field at the p/n junction, they’ll only go one way. The electron is
drawn to the n-side, while the hole is drawn to the p-side. The mobile
electrons are collected by the metal fingers at the top of the cell. From
there, they flow through an external circuit, doing electrical work, like
powering a lightbulb, before returning through the conductive aluminium sheet
on the back. Each silicon cell only puts out half a volt, but you can string
them together in modules to get more power. Twelve photovoltaic cells are
enough to charge a cellphone, while it takes more modules to power an entire
house. Electrons are the only moving parts in a solar cell, and they all go
back where they came from. There’s nothing to get worn out or used up, so solar
cells can last for decades. (Komp, how do solar panels
Why is the
sun so important?
The sun is important for all living organisms. The sun
warms the seas, generates the weather, stirs the atmosphere. Another important
job the sun has is to give energy to the green plants, so they can make oxygen
for life on earth (Beladal, 2016). The sun is used as
an energy source by coming through windows and heating up the houses(Elise, 2016). The sun warms the
surface of the Earth, regulates the weather, and makes a habitable environment
for the life on earth. We also need the light from the sun to be able to see
objects. People and animals need the solar energy to survive. The sun plays a
really important role in photosynthesis to encourage plant growth (Reference, 2017). The sun is
important for the growth on the earth. The sun is important for meat, fruit and
grains (Eia, 2016). Solar is Latin for
sun and the sun is a powerful source of energy. There is a big amount of energy
in the sun, and its really available, and by modern technology we can used it
to make our life easier (Eschool, 2017).
cons of solar panel
An advantage with solar energy is that it does not
produce air pollutants or carbon dioxide. It does not influence the
environment, and does not destroy it. The earth receives much more energy each
day than the people can consume. (Eia, 2016) It is possible tower
the entire world just by using the sun and modern technology. You need a lot of
space for the solar panels, but the Sahara Desert is over 3 million square
miles in area. The solar cells are getting better and cheaper. The other energy
sources get competition. Poor people also can get it since it’s cheaper (Komp, how do solar panels
Solar energy is renewable. This means that you can not run out of it. If the
sun is alive, are we able to use its energy. The sun will be alive for 6.5
billion more years according to NASA. There are no moving parts in the
application used to make solar power. There is neither no noise in the making.
They don’t need a lot of maintenance (Maehlum, 2017).
Some of the disadvantages with solar panels are for
instant the problem with the sunlight coming to the earth not being consistent.
It really depends on the location, the time, the season and the weather. It can
be hard to only rely on the sun energy alone. (Eia, 2016) It’s unevenly
distributed on our planet. It would require a way to get electricity from one
place to another. (Komp, how do solar panels
there are some emissions associated with the transportation and installation.
Reduces our dependence on the other non-renewable energy sources though.
Important in the fight against climate change. (Maehlum, 2017)