Solar Energy
• Directly or indirectly the sun is responsible for
all of the energy on earth.
• Direct solar energy is a clean, renewable
energy resource that is easily vast enough to
provide us with all of our energy needs.
• There are 3 main ways we can harvest solar
energy: Solar hot water, Solar thermal
electricity, and Photovoltaic cells.
Solar Map of the US
http://www.seia.org/galleries/default-image/Solar%20Map--US.gif
Can solar power provide a
significant proportion of energy
demand in the future?
http://www.ases.org/
Why solar power has potential
• Development of solar technologies started
back in the 1860s.
• Only a small fraction of the available solar
energy is actually used.
• It is inexhaustible.
• Quiet and clean.
• Does not put CO2 into the atmosphere
• Creates jobs.
• Although solar panels or solar lights are costly,
money is saved in the long run.
• Also, having an array of solar panels on your roof
can be used to generate power directly for your
home.
http://www.darvill.clara.net/altenerg/solar.htm
• Sunlight is converted to energy through a variety of
technologies.
• If properly designed, buildings can use daylight all year
round by capturing the sun’s heat in the winter and
reducing it in the summer.
http://www.darvill.clara.net/altenerg/solar.htm
• Increasing value of passive solar.
• Businesses and industries are using it.
• It is expected that solar energy technologies
will have a significant growth in the 21st
century.
Google images
Does our group agree with the
evidence??
YES!!!!!!!
Issues With Efficiency
•Solar panels are not cheap and because they are
constructed from expensive fragile materials that
must constantly be maintained and often replaced.
•Since each photovoltaic panel has only about a
40% efficiency, single solar panels are not sufficient
power producers.
•About one-third of sunlight is reflected back into
space, and some is absorbed by the atmosphere.
Enhancing Efficiency
• Passive solar design will minimize heat in
summer and capture it in winter.
• Innovative designs and processes are driving
down costs.
• Solar energy is captured more in space than on
Earth.
A Passive Solar Design
Solar Power Satellites
• Can be perfectly aimed at the sun
• Microwaves are beamed to rectenna fields that
rectify the microwave beams and distribute the
energy to users.
• Sunlight would not be blocked, except for a
few hours during equinoxes.
Earth Energy Distribution
Environmental Issues
• There are several problems with solar energy
production that negatively impact our environment.
There is a danger of toxic chemical pollution from heavy metals
used in photovoltaic cells.
Lead-acid batteries are used in some systems for storage.
Large amounts of land are required for solar farms.
Large scale production of solar energy may have negative effects
on the environment.
A significant amount of non-renewable energy is consumed in
the manufacture of mirrors and solar panels.
Solar Panels are dangerous to firefighters.
Pollution From Solar Energy
• Heavy metals, such as arsenic, gallium and cadmium, may be
used in photovoltaic cells. These metals are hard to recycle,
and there is a danger of toxic chemical pollution from these
materials.
• Workers who come in contact with these substances are
subjected to health and safety hazards
• Silicon can also be harmful to workers if they breathe it in as
dust.
• Workers involved in manufacturing photovoltaic modules can
be protected from exposure to these materials without much
trouble.
• These hazards are no different than any other source of energy
production.
Lead-Acid Batteries
• Lead-Acid batteries are used in some solar
systems to store electricity that is generated.
• These batteries pose a problem to the
environment because they are hard to dispose
of, since chemicals from them can leach into
the soil and water, causing contamination.
• Currently attempts are being made to develop
alternatives to the lead-acid battery.
Large Land Requirement
• A large amount of land is required for large
scale solar power plants.
• Approximately one square kilometer for every
20-60 megawatts.
• Generating electricity from coal requires as
much or more land per unit of energy
delivered.
Negatives of Large Scale
• The large area of land required for solar-thermal
plants can be a have a harmful effect on wildlife
populations.
• Solar-Thermal plants require cooling water which
is scarce and costly in desert areas.
• If too many solar collectors are placed in one area
changes in local weather conditions or worse may
occur.
• Fortunately, large central power plants are less
effective than small-scale dispersed applications.
Dangers to Firefighters
• Solar Panels cannot be shut down are always
energized with up to 600 volts of DC current.
• The only way to de-energize a solar panel is to
cover it and wait about a week.
• Water cannot be put on these panels because
they are charged with electricity, and these
panels may be lethal if you come in contact
with them.
• The best way firefighters can deal with houses
that have solar panels is to let them burn.
Political Problems
• The energy department plans to spend $159
million on solar research and development. It will
spend nearly double, $303 million, on nuclear
energy research and development, and nearly
triple, $427 million, on coal, as well as $167
million on other fossil fuel research and
development.
• Fossil fuels as we know are an un-renewable
source of energy and will run out in our life time.
Solar Energy too Costly?
• The main reason the government is spending
such a low percentage of funds on solar energy is
because it is a costly technology.
• Demand for manufacturing silicon from the solar
energy and semiconductor industries has led to
shortages that have temporarily driven up
photovoltaic costs.
• As the technology becomes more developed costs
will greatly decrease and become far more
practical.
Cost is worth the reward
• Solar energy easily has the potential to provide
electricity for our entire planet in a renewable
fashion.
A scientist trying to cut solar energy costs.
http://www.nytimes.com/2007/07/16/business/16solar.html?_r=1&hp&oref=slogin
Social Problems
• Some utility companies continue to resist gridconnected PV systems.
• Companies such as Citizenre offer claims to provide
“free” solar panel installations and provide
homeowners with solar electric power for the same
price as they currently pay for electricity.
• These claims are obviously bogus and people who
sign up for Citizenre are no longer potential
customers for real PV dealers.
Local and U.S. Solar Regulations
•There are no laws/regulations that prevent solar
development in the Northeast Pennsylvania area
•On a national level, the U.S. wants to decrease
solar exporting…
•Basic solar research funding comes almost
entirely from the U.S. government
•Due to petty politics, solar funding has received
less attention.
Other Industrialized Countries
•Aggressive financial incentives in Germany
and Japan have made these countries global
leaders in solar deployment for years.
• Currently in the UK there are grants
available to help you install solar power in
your home.
•In the United Kingdom, solar power isn't
much use for high-power applications, as you
need a large area of solar panels to get a
decent amount of power.
Power to the People!
You can legally prevent your
neighbors' trees from growing tall
enough to shade your site
Conclusion
• Solar energy has the capacity to provide all
of the energy we will ever need.
• We have the ability to harvest this energy, but
we must invest more money and further
develop and perfect the technology at hand.
• Therefore we believe that solar energy is the
energy of the future and can solve all of our
energy demands including eliminating the
pollution caused by other forms of electricity
generation.
Any Questions?
(Former president George W. Bush)