

Direct : involves only one transformation into a usable form.
– Sunlight hits a photovoltaic cell creating electricity.
Indirect : involves more than one transformation to reach a usable form. Many other types of power generation are indirectly solar-powered.
– Hydroelectric dams and wind turbines are indirectly powered by solar energy through its interaction with the Earth’s atmosphere.
http://en.wikipedia.org/wiki/Solar_power

o Passive : is a broad category of techniques for regulating a building’s indoor air and domestic water temperatures, using climate, site features, architectural elements, and landscape materials. o Active : refers to a system which uses additional mechanisms such as circulation pumps, air blowers or automatic systems, which aim collectors at the sun.
( http://en.wikipedia.org/wiki/Solar_energy )

o Flat-Plate Collectors : are arrays of solar panels arranged in a simple plane; more commonly used type of collector.
o Focusing Collectors : are flat-plate collectors with optical devices arranged to maximize the radiation falling on the focus of the collector; used in few scattered areas.
o Passive Collectors : absorb radiation and convert it to heat naturally, without being designed and built to do so.
( http://www.ccs.neu.edu/home/feneric/solar.html
)

 Solar energy can be converted into numerous kinds of uses.
 Through these uses, it can replace numerous non-renewable sources such as petroleum, natural gas, and coal

 Americans especially depend on petroleum, but it is slowly diminishing as a resource and needs an alternative
 Petroleum is used as the main source of energy for vehicles

 Natural gas is mainly used for heating homes
 Active and passive heating systems in homes.

 Coal is used to power a great majority of power plants
 A non-renewable source will eventually run out
 Produces a lot of emissions and is difficult to transport

 Power cars
 Heat homes
 Power electric plants

 Solar energy is less expensive to produce
 When the source runs out, the world will end and there will be no reason for the source
 Solar energy can almost

 Uses natural materials or absorbing structures to gather and hold heat
 The adobe dwellings and stonewalled buildings collect heat during the day and release at night
 Does not involve much technology
 pumps a heat-absorbing fluid medium through a small collector
 Also, does not involve much technology
Cunningham, William et al. Environmental Science A
Global Concern. New York, NY: McGraw-Hill Companies
Inc., 2005.
www.lucianofamily.net/.../ SanIldefonso-Pics.html

 In 1958, Vanguard I powered by 6 palmsized photovoltaic cells cost $2000 per peak watt of output
 1970, $100 per watt
 2003, approaching $5 per watt
 Last 25 years, efficiency of energy has increased from less than 1% of light to more than 10 % and over 75% in the lab
Cunningham, William et al. Environmental
Science A Global Concern. New York, NY:
McGraw-Hill Companies Inc., 2005.

 Solar cells that produce electricity directly from sunlight

 Made up of silicon operate by the photovoltaic effect
 In the future, this solar power could affect your solar power independence
 Has no moving parts, no pollution, lifetime equal to fossil fuel or nuclear power plant
Cunningham, William et al. Environmental Science A
Global Concern. New York, NY: McGraw-Hill Companies
Inc., 2005.
http://www.solarenergy.com/ws400CS.cgi?category=info
_photovoltaics.html&cart_id=1051025104306148&dci=

 Two ways of storing energy
–
–
Electrical- battery
Electrochemical- gas tanks

 uses exotic metal alloys; gallium arsenide, semi-conducting polymers of polyvinyl alcohol
 College students all over North
America race solar-powered cars every year to test solar technology
 Aurora IV was engineered by undergraduate students of
University of Minnesota
 Facts: Aurora IV has over 1,900 solar cells, top speed of Aurora 4 is over 80 mph, At 55 mph, the Aurora
Cunningham, William et al. Environmental Science A Global
Concern. New York, NY: McGraw-Hill Companies Inc., 2005.
4 only uses the power of a 1600 watt hair dryer http://www.despovartes.com/projects/umnsvp/aurora4/index.html

• Grid-connected central stations require significant land usage
• The manufacturing of
PV cells generates hazardous materials http://www.eere.energy.gov/solar/images/photo_01224.jpg

•Solar energy systems are silent and create no pollution or waste while operating
• Solar Energy is a renewable resource and its use does not disturb ecosystems http://cas.bellarmine.edu/tietjen/Ec&Ev_Distance_learning/Ecol ogyIntro/ecosystem.gif

 Yes.
– Environmentally friendly
– Costs are now comparable to alternative energy sources
– Renewable Resource