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/

• 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.

Why solar power has potential

• 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.

http://www.nytimes.com/2007/07/16/business/16solar.html?_r=1&hp&oref=slogin

A scientist trying to cut solar energy costs.

Social Problems• Some utility companies continue to resist grid-

connected 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.

(Former president George W. Bush)

Any Questions?