Solar Energy

by Daniel Weiner and Mark Schneider


1. How is it obtained?

http://seniord.ee.iastate.edu/may0616/website/solar2_files/image002.jpg
http://seniord.ee.iastate.edu/may0616/website/solar2_files/image002.jpg

When the sunlight hits the panel, the electrons move around and create electricity. This electricity then goes through wires that are connected to the panel.
Very informative video (too bad we can't use YouTube during school!):

Two types:
Thermal: solar energy -> heat
Photovoltaic: solar energy -> electricity

http://www.eia.doe.gov/fuelrenewable.html


This is what a solar panel looks like:
http://myhomezine.com/wp-content/uploads/2009/12/solar%20energy.jpg
http://myhomezine.com/wp-content/uploads/2009/12/solar%20energy.jpg


2. How efficient is it?

Solar Energy is not very efficient. For example, the average photovoltaic (PV) panel is only around 20% efficient. However, silicon designs are around 40% efficient. While some scientists have discovered solar panels that are up to 80% efficient, the current focus is on making the panels cheaper.

http://poweredbysolarpanels.com/solar-panel-efficiency

3. How available is it?

Although the Earth absorbs about 3,850,000 exajoules of solar energy every year, it is not always available. For instance, there is no solar energy at night. However, batteries can be attached to store excess sunlight that is absorbed during the day. Also, many areas far from the equator undergo periods in which there is no sunlight for many days. However, solar energy is abundant. The amount of solar energy that hits the Earth in one hour is greater than the amount that the world uses in one year.

http://www.energy-consumers-edge.com/pros_and_cons_of_solar_power.html
http://www.ehow.com/about_5518265_availability-solar-energy.html
http://www.solarenergy.org/younger-kids

Solar power potential:
http://www.fsec.ucf.edu/en/media/newsletters/echron/archives/2006/Q2/images/solar_resourse_map.jpg
http://www.fsec.ucf.edu/en/media/newsletters/echron/archives/2006/Q2/images/solar_resourse_map.jpg



4. How much does it cost?

Although the initial cost of solar energy is very high, it ends up being cost effective in the long run.

Initial costs for various solar panels:
Solar
Panel
Manuf.

Model
Watts
Voltage
Price
per Watt
(US $)

Price
(US $)

BP
SX170B
170
24V
$4.55
773.50
Isofoton
I-150S
150
24V
$4.68
702.00
GE
GEPV-173
173
18V
$4.75
831.25
GE
GEPVp-200
200
18V
$4.80
960.00
Photowatt
PW 1650
165
12/24V
$4.50
742.50
Photowatt
PW1650
155
12/24V
$4.50
697.50
Photowatt
PW 750
80
12V
$4.59
367.20
Sharp
NE-185U1
185
24V
$4.94
913.90
Sharp
NT-175U1
175
24V
$4.82
843.50
Sharp
NE-170U1
170
24V
$4.32
734.40
Sharp
ND-208U1
208
18V
$4.29
892.32
Sharp
ND-200U1
200
18V
$4.29
858.00
http://seniord.ee.iastate.edu/may0616/website/solar2.htm

5. What are the environmental impacts?

Overall, solar energy is very good for the environment. It is a renewable resource which limits the amount of greenhouse gases emitted into the atmosphere. Although solar power doesn't pollute while it is in operation, the process by which solar panels are made does produce some pollution. However, this pollution is minimal compared to the amount of pollution that is saved by using solar power.

http://www.facts-about-solar-energy.com/solar-energy-advantages-disadvantages.html
http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html


Solar Energy Pros:
  • Little to no pollution
  • Quiet
  • Able to be used easily in rural areas
  • More cost effective over time
  • Compact and easily placed on roofs
  • Renewable
Solar Energy Cons:
  • Initial cost
  • Only can be used when there is sunlight
  • Hard to use in polluted areas
  • Not very efficient

http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html
http://seniord.ee.iastate.edu/may0616/website/solar2.htm

Other Good Websites
http://www.energyquest.ca.gov/story/chapter15.html
http://tonto.eia.doe.gov/kids/energy.cfm?page=solar_home-basics-k.cfm
http://www.eia.doe.gov/fuelrenewable.html
http://environment.nationalgeographic.com/environment/global-warming/solar-power-profile/
http://ngm.nationalgeographic.com/2009/09/solar/johnson-text
http://www.scientificamerican.com/article.cfm?id=how-does-solar-power-work