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CHAPTER 20: SUSTAINABLE ENERGY
By: Jack PhilbinDr Unfried APES2/9/10
ENERGY EFFICIENCY
a measure of energy produced compared to energy consumed.
Our current energy technologies are extremely inefficient and much potential energy in fuels is wasted.
Conservation is the best way to alleviate these issues
COGENERATION
production of both electricity and steam in the same plant.
Increases efficiency by 50%
One of the fastest growing energy sources
SOLAR ENERGY
The amount of solar energy reaching the earth's surface is approximately 10,000 times all the commercial energy used each year.
Passive Heat Absorption- Using natural structures just to gather and store heat
Active Solar Systems- Pump a heat-absorbing fluid through a small collector
SOLAR ENERGY CONTINUED
Parabolic mirrors aew curved reflecting surfaces that collect light and focus it into a concentrated point
These are used in High-Temperature Solar Energy, as a fluid is run through a central tube to the collector.
PHOTOVOLTAIC CELLS
Capture Solar Energy and convert it directly to electrical current
Separate electrons from Parent Atoms, and accelarate them across an electrostatic barrier
ELECTRICAL ENERGY
Electrical energy is difficult and expensive to store.
Different Batteries have different drawbacks, from corosive acid to lifespan, to storage capacity.
The Sodium-Sulfur battery has potential for large-scale storage, but are extremely expensive
FUEL CELLS
Devices that use ongoing electrochemical reactions to produce an electrical current.
Provides direct-current electricity as long as it is supplied with hydrogen and oxygen.
When run on pure oxygen, waste is minimal.
BIOMASS
Plants capture about 0.1% of all solar energy that reaches the earth's surface.
Wood provides less than 1% of the energy in the United States
Overall, United States wood burning has increased, though it is inefficient and has a high level of pollution
DUNG AND METHANE FUELS
In countries with wood shortages, Animal Manure is burned
When it is burned, more than 90% of the potential heat and most of the nutrients are lost.
Burning methane extracted from Dung is much more efficient, less of a pollutant, and can help fertilize land.
BIOMASS FUELS
Ethanol and methanol are produced by anaerobic digestion of plant materials with high sugar content.
Biofuel is a mixture of gasoline and ethanol, and is often used in automobile engines
HYDROPOWER
Water power is about 25% of total electrical generation
Currently, we use only about 10% of the available water power.
Dams produce most of the Hydropower in the United States
Micro-hydro generators are able to power single homes when submerged in current
WIND POWER
Wind power has the capacity to produce 50 times the world nuclear generating capacity.
Endless resource, does little damage Concentrated in large collections of
wind turbines known as Wind farms
GEOTHERMAL ENERGY
The earth's internal temperature can provide a useful source of energy
Has been used in industrial processes, agriculture, and sometimes aquaculture
No mining or transportation of fuels, and little waste disposal.
TIDAL AND WAVE ENERGY AND OTEC
Similar to Hydroelectric Dams Major environmental impact concern,
as it disrupts aquatic habitats to a great extent
Ocean Thermal Electric Conversion- uses heat from sun warmed upper ocean layers to evaporate a working fluid.
Cost, Saltwater corrosion, and ecological destabilization are the downsides
OUR ENERGY FUTURE
None of the energy sources mentioned will completely replace fossil fuels
Renewables provide about 40% of the energy produced in the U.S.(World Energy Council 2007)
By the end of the 21st century, Renewables should make up all of our energy production, according to the same council
WORKS CITED
http://www.wec.cz/en/documents/20wec2007/2007%20Survey%20of%20Energy%20Resources%20Executive%20Summary.pdf
(World Energy Council Summary)
Cunningham & Co’s Environmental Science: A Global Concern: Ninth Edition
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