past:
present:
There are a variety of ways to make electricity. For example there is nuclear, fossil fuel, geothermal, hydroelectric and wind. Among these there’s also solar energy. This form of energy is very convenient because the fact that it’s renewable.
How exactly does solar energy work? Solar panels need
a specific location to be placed. This site needs to be where the panels
can get an abundant number of sun. Then they get the panels from the manufacture
and install them. Inside these panels there are photovoltaic (PV) cells.
When sunlight (photons) strike the PV cell, some photons pass right through, some are reflected and the other photons are absorbed. The absorbed photons hit electrons and make them lose their place around the nucleus of the atom. The electrons then cross a barrier that’s located inside the panels.
The only way the electrons can get back is by connecting the positive side to the negative
side of the panel with a wire. When this happens it creates a direct current (DC). For
example, DC is when a battery is connected the electricity goes in a straight line and
when it’s disconnected it just stops. The DC has to go through a certain machine called
an inverter that changes DC into alternating current (AC). AC instead of going in a
straight line it goes up and down. This has to happen because things in a home run on
AC.
The diagram to the left shows that the electrons (red
circles) cross the barrier into the positive side (dark blue). It also
shows the wire in which the negative and positive sides are connected
(3).
Some people think that solar energy can work anywhere in the United States. In some cases that’s not true. For instance Washington, Oregon, Montana and other northern states don’t receive much sunlight. These states wouldn’t be a very convenient location to use solar electricity. Many people would agree that Nevada, Utah, Colorado, Arizona, New Mexico, part of California and part of Texas are the best states for solar power to be used (6). Why? Simply because these states are also desert and they receive much sunlight.
The map to the right shows where solar power works best
in the United States. The places in the map that are color blue get the
least amount of sun. The places with red get the most amount. This means
that the red places are the best locations to use solar electricity (6).
Yet this source of energy has some disadvantages. This source pollutes when the panels are being manufactured (1). They use certain types of chemicals that aren’t very clean. Also solar energy can’t be used anywhere, they have to have a certain location. Another problem is that when electricity is most needed at night the sun isn’t out. The batteries that store the electricity are very expensive, such as the solar panels.
On the upside solar energy has advantages too. It’s very economical once the systems
working (2). It also doesn’t pollute once the panels have been made (1). Also if people
live where utility poles aren’t around, instead of going through the expense of building
them they can use solar panels. Some people worry how this type of energy doesn’t work
at night, well they don’t have to worry because there are certain kinds of batteries that
store the electricity (1).
This source of energy is probably not going to be used as much as some people want it to be because everybody doesn’t have easy access to it. Yet it’s recommendable because it’s renewable and non-polluting.
Sources
1. "Photovoltaics - Solar Electricity" Texas Solar Energy Society http://www.txses.org/index.php?sessionid=
2. " Why Solar Energy? " Solar Services INC. The Professionals http://www.solarservices.com/default.htm
3. "Solar Cells or Photovoltaic Energy" Energy Quest Ask Jeeves for Kids " How does solar electricity work?"
4. "About Photovoltaics Turning Sunlight into Electricity" Million Solar Roof
http://www.ereb.doe.gov/millionroofs/whatispv.html
5. " Using silicon to convert photons to electrons" How Stuff Works http://www.howstuffworks.com/solar-cell.htm/printable
6. “Average Daily Solar Radiation, 1961-1990”,HOME POWER
THE HANDS-ON JOURNAL OF HOME-MADE POWER http://www.homepower.com
7. “Installing your solar power components”, Solar4Power, http://www.solar4power.com/solar-power-installation.html