Voices Plus Rogério Tilio (organizador) Richmond Página 1 voices plus 3 rogério tilio



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. Accessed on January 11, 2016. Occasional linguistic adjustments to fit standard language marked with [ ].

What is Energy

What is Energy?

“[…]


What are the Sources of Energy?

Primary energy sources (meaning energy is created directly from the actual resource) can be classified in two groups: nonrenewable or renewable. Secondary sources are derived from primary sources.

[Nonrenewable] Energy Sources – Energy from the ground that has limited supplies, either in the form of gas, liquid or solid, are called nonrenewable resources. They cannot be replenished, or made again, in a short period of time. Examples include: oil (petroleum), natural gas, coal and uranium (nuclear). Oil, natural gas and coal are called ‘fossil fuels’ because they have been formed from the organic remains of prehistoric plants and animals.

Renewable Energy Sources – Energy that comes from a source that’s constantly renewed, such as the sun and wind, can be replenished naturally in a short period of time. Because of this we do not have to worry about them running out. Examples include: solar, wind, biomass and hydropower. Currently, about 20% of the world’s electricity comes from renewable resources. There is a global debate as to whether geothermal energy is renewable or nonrenewable.



Secondary Energy Sources – Energy that is converted from primary sources are secondary sources of energy. Secondary sources of energy are used to store, move, and deliver energy in an easily usable form. Examples include electricity and hydrogen.”
Página 108

a) coal; b) wind; c) hydrogen; d) geothermal; e) hydropower; f) solar; g) biomass; h) nuclear; i) oil; j) electricity; k) natural gas.

a



b



c



d



e



f



g



h



i



j



k

PHOTOS: A- JOHN_KASAWA/ISTOCKPHOTO, B- CARD76/ISTOCKPHOTO, C- CLEMENS BILAN/AFP/GETTY IMAGES, D- CHRISPOLE/ISTOCKPHOTO, E- KEITHSZAFRANSKI/ISTOCKPHOTO, F- JASON DOIY/ISTOCKPHOTO, G- ANDREI MERKULOV/ISTOCKPHOTO, H- MICHAELUTECH/ISTOCKPHOTO, I- LEOFRANCINI/ISTOCKPHOTO, J- LISA VALDER/ISTOCKPHOTO, K- HAZLAN ABDUL HAKIM/ISTOCKPHOTO


Página 109

2 Choose one of the energy sources mentioned in activity 1 and read about its pros and cons. Then work in groups of three with classmates that have read about other energy sources and share your information.



Energy Source Comparison

Energy Source

Pros

Cons

Solar Energy



• [Nonpolluting]

• Most abundant energy source available

• Systems last 15-30 years


• High initial investment

Dependent on sunny weather

• Supplemental energy may be needed in low sunlight areas

• Requires large physical space for PV cell panels

• Limited availability of polysilicon for panels


Wind Energy

• No emissions

• Affordable

• Little disruption of ecosystems

• Relatively high output




• Output is proportional to wind speed

• Not feasible for all geographic locations

• High initial investment/ongoing maintenance costs

• Extensive land use




Hydropower



• No emissions

• Reliable

• Capable of generating large amounts of power

• Output can be regulated to meet demand




• Environmental impacts by changing the environment in the dam area

• Hydroelectric dams are expensive to build

• Dams may be affected by drought


Natural Gas



• Widely available

• Cleanest-burning fossil fuel

• Often used in combination with other fuels to decrease pollution in electricity generation

• Made safe by adding artificial odor so that people can easily smell the gas in case of a leak




• Transportation costs are high

• Lack of infrastructure makes gas resources unavailable [for] some areas

• Burns cleanly, but still has emissions

Pipelines impact ecosystems




ENERGY4ME.ORG
Página 110

Energy Source

Pros

Cons

Petroleum / [Oil]




• Efficient transportation fuel for the worl

• Basis of many products, from prescription drugs to plastics

• Economical to produce

• Easy to transport




• High CO2 emissions

• Found in limited areas

• Supply may be exhausted before natural gas/coal resources

• Possible environmental impact from drilling/transporting




Biofuels




Abundant supply

• Fewer emissions than fossil fuel resources

• Can be used in diesel engines

• Auto engines easily convert to run on biomass fuel




• Source must be near usage to cut transportation costs

• Emits some pollution as gas/liquid waste

• Increases emissions of nitrogen oxides, an air pollutant

• Uses some fossil fuels in conversion




Coal




• Abundant supply

• Currently inexpensive to extract

• Reliable and capable of generating large amounts of power


• Emits major greenhouse gases/acid rain

• High environmental impact from mining and burning, although cleaner coal-burning technology is being developed

• Mining can be dangerous for miners


Uranium / [Nuclear]




• No greenhouse gases or CO2 emissions

• Efficient at transforming energy into electricity

• Uranium reserves are abundant

• Refueled yearly (unlike coal plants that need trainloads of coal every day)




• Higher capital costs due to safety, emergency, containment, radioactive waste, and storage systems

• Problem of long-term storage of radioactive waste

• Heated waste water from nuclear plants harms aquatic life

• Potential nuclear proliferation issue




Geothermal




• Minimal environmental impact

Efficient

• Power plants have low emissions

• Low cost after the initial investment




• Geothermal fields found in few areas around the world

• Expensive start-up costs

• Well could eventually be depleted


ENERGY4ME.ORG

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