Solar Energy

From wiki.NGSciEd.org

ISCI 2001 Kayla P. Jessie B. Mary Rose L.

Contents 1 Energy from the Sun 2 Solar Technology 3 Solar Panels 4 Pros of Solar Energy 5 Cons Of Solar Energy 6 Percentage of Energy 7 Places of the World 8 Type of energy 9 Solar Energy of Today 10 Discussion Questions 11 Resources for the Classroom 12 Key Terms 13 References Cited

Energy from the Sun

Solar Energy is energy derived from the sun in the form of solar radiation. Every day the sun radiates, or sends out, an enormous amount of energy. During a process called fusion, four hydrogen atoms combine to form one helium atom, with a loss of matter. This matter is emited as radiant energy (Secondary Energy Infobook 2007).

Solar power is energy from the sun. The sun produces energy by consuming hydrogen in nuclear fusion reactions. Solar energy is transmitted to the earth in portions of energy called photons. The earth receives and collects solar energy in the atmosphere, plant life, and in oceans. There is then technology that converts the solar radiation into electricity.

Solar Technology

Most of the renewable energy on Earth is made up of solar radiation, along with secondary solar resources such as wind and wave power, hydroelectricity, and biomass. Solar energy is converted by solar power technologies via heat engines or photovoltaic panels;called solar panels.There are two types of ways to use solar energy, passive and active. No mechanical equipment is needed for passive heating. However an active heating system requires a collector to absorb and collect solar radiation. Solar power is being used by us in two forms thermal energy and solar electric energy.Solar heating harnesses the power of the sun to provide solar thermal energy. Thermal energy is then used to heat water in homes, and to heat buildings,and to heat pools.

• Solar Radiation: The electromagnetic radiation and particles (electrons, protons, and rarer heavy atomic nuclei) emitted by the sun.

Solar Panels

• Solar panels are devices that convert light into electricity. They are called "solar" panels because most of the time, the most powerful source of light available is the Sun, called Sol by astronomers. Some scientists call them photovoltaics which means, basically, "light-electricity." A solar panel is a collection of solar cells. Lots of small solar cells spread over a large area can work together to provide enough power to be useful. The more light that hits a cell, the more electricity it produces(Power n.d.).The panels consist of a positive and a negative slice of silicon. As the protons of the sun beat down onto the solar panel neurons are knocked off of the silicon. The negatively charged free neutrons are attracted to the silicon but are trapped by the magnetic field that is formed from the opposing fields. Small wires on the silicon catch these neutrons and when connected in a circuit an electric current is formed.

How solar panels are made. This is a video from the TV show How it's made and it shows how solar panels are made.

Pros of Solar Energy

• When you have solar energy you are less dependent on the world’s fossil fuel supplies. The sun has an unlimited about of source; therefore you are not limited by the world.
• The overall costs of solar panels are cheaper and cost less in your home. The first installment is expensive but they end up paying for themselves after a couple years.
• The solar panels can be installed on your roof top. Does not take up much room and you do not have to worry about your power poles and wires.
• To install solar panels cost less than to run high voltage wires through space and other remote locations.
• Solar energy can give off energy to remote locations that are not linked to our map. The most used example is space. The satellites are powered by high efficiency solar cells.
• The solar panels give off no pollution. The only type of pollution that is produced from solar panels is when the panels are manufactured. The factories, transportation of the panels and sometimes the process of installing the panels are the only types of pollution given off. Pros and Cons. 2007)

Cons Of Solar Energy

• Solar panels would have problems in the major cities because of the pollution. Pollution levels affect the solar cells efficiency, because the sun does not have a clear focus on the panels.
• The weather can affect the use of the panels. This means on cloudy days and when we have storms, they do not produce as much as we need.
• The solar energy is only able to generate electricity during the daytime. This means at night, our solar panels would not be outing out energy for our homes.
• The number one problem with solar energy is the fact that the initial cost of the panels can be over $1000. Some households need more than one and they do not have this type of money to spend. (pros and cons. 2007)

Percentage of Energy

• Cumulative solar energy production accounts for less than 0.01% of total Global Primary Energy demand(Fast Solar Energy Facts 2007).
• Solar cells account for less than 1% of the world's electricity production(Fast Solar Energy Facts 2007).
• Only 7.5 percent of total U.S. energy consumption came from renewable sources in 1998. Of that total, 94 percent was from hydropower and biomass. (energy Fact.n.d)

Places of the World

-This is NASA’s map of solar energy hitting earth’s surface. Red is highest level(Fuller 2007).

• The two sunniest spots on earth are in the Pacific south of Hawaii and in the Sahara in the nation of Niger. Lots of sun, no clouds. This map is based on over two decades of digital date collected by satellites. NASA’s brains and computers then generated this map. It’s explicitly being released now to help solar engineers and investors decide where to place their solar collectors(Fuller 2007). These spots of high levels of solar energy are ideal for the use of the suns energy for electricity because of the large space and large accumulation of energy.

Type of energy

• Solar radiation along with secondary solar resources such as wind and wave power, hydroelectricity and biomass account for most of the available renewable energy on Earth. Renewable energy is energy generated from natural resources—such as sunlight,wind, rain, tides and geothermal heat—which are renewable (naturally replenished). Solar energy is a renewable sustainable resource because it is continually made and replenished with the energy absorbed from the sun (Secondary Energy Infobook 2008).

Solar Energy of Today

• In effort to switch to solar energy and provide a cleaner and greener enviornment LG phone distributers have come up with a solar energy powered phone for the near future.

-The panels, which take up most of the back panel of the phone, can gather and convert enough solar power in ten minute's of bright sunlight to power a three-minute phone call, and are claimed to be able to recharge the phone completely "'if left in natural light for long periods."

• While trying to better improve the use of solar energy and the ways of converting the most energy from the sun by use of solar cells and panels researchers have run across set backs. To better im prove these cells and panels researchers are studying the wings of butterflys.

-A butterfly’s wing can help us enhancing the solar power efficiency. Butterfly wings have scales that act as tiny solar collectors. Researchers from China and Japan are working on designing more efficient solar cells while taking inspiration from the butterfly wings. If successful, this discovery may lead to powering homes, businesses and other applications in the future.

(Solar Energy From Butterfly Wings?. February 10,2009. Retrieved February 17, 2009, from http://www.alternative-energy-news.info/solar-energy-from-butterfly-wings/)

Discussion Questions

• Do you think that solar panels are a good investment? Are they worth the money they cost?
• Should the government take a more leadership role in stepping forward in solar energy? What could they do to influence everyone else?
• Who is the main leader in the trend of solar energy?
• Which part of the world does solar energy work best at and why?
• Is solar energy a sustainable resource?

Resources for the Classroom

• http://www.eia.doe.gov/kids/classactivities/teachers&students.html
• http://apps1.eere.energy.gov/education/lessonplans/topic.cfm/topic_id=9

Key Terms

Solar Energy

Renewable Energy

Solar Panels

Solar Radiation

References Cited

1. Pros and cons of Solar Energy. 2007. Retrieved February 15, 2009, from http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html
2. Secondary Energy Infobook."The Need Project." 2008. Retrieved February 15,2009, from http://www.need.org/needpdf/infobook_activities/SecInfo/SolarS.pdf
3. Power.(n.d.) Retrieved February 16, 2009, from http://www.qrg.northwestern.edu/projects/vss/docs/power/1-what-are-solar-panels.html
4. SEI:Energy Facts.(n.d.) Retrieved February 16, 2009, From http://www.solarenergy.org/resources/energyfacts.html
5. Fuller,Harry. NASA maps world's hot spots,a road map for solar? November 28, 2007. Retrieved February 16, 2009, from http://blogs.zdnet.com/green/?p=538
6. Fast Solar Energy Facts. 2007. Retrieved February 15, 2009, from http://www.solarbuzz.com/FastFactsIndustry.htm
7. (Harris, Mark. LG Announces Solar-Powered mobile.2009. Retrieved February 17,2009, from http://www.techradar.com/news/phone-and-communications/mobile-phones/lg-annouces-solar-powered-mobile-532224)