Download L`energia - Programma LLP

Energy in our life
1. Forms of energy:
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Mechanical energy
Nuclear energy
Electric energy
Chemical energy
Thermal energy
2.
3.
4.
5.
Consumption in the world;
Consumption in Italy;
Consumption in Sicily;
Renewable energy in Sicily:
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Solar energy;
Wind energy;
Hydroelectric energy;
6. Why save energy?
Mechanical energy
In mechanics, there are two types
of energy:
• Kinetic energy:that is the
energy of a moving body because of
its motion.
• Potential energy : ,usually
denoted by U, is the ability to do
work that the body possesses by
virtue of his position within a field
of conservative forces.
Nuclear energy
• Nuclear energy includes all sorts of phenomena which have
energy production due to changes in atomic nuclei. The
nuclear energy, along with renewable and fossil sources, is a
primary energy source, that is present in nature and it is not
derived from the processing of other forms of energy.
Nuclear, positive or not?
Benefits …
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A nuclear power plant does not radiate CO2.
Nuclear power plants do not produce carbon dioxide, nitrogen and
sulfur, the main causes of the greenhouse effect.
Economic advantage: the production of a nuclear energy reduces the
amount of oil and the dependence of economies on oil. All this leads to
an increased stability of the national and global economic sectors.
Disadvantages …
Consequences of incidents:.
The radiation to which the population is exposed, causes risk of death
from leukemia to cancer.
Nuclear localization:
The process of locating a nuclear plant and the storage of its waste is
very difficult. Few nations are willing to sacrifice their land to host the
nuclear waste.
Electric energy
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Electricity is a form of energy due to forces and fields of electrical origin, or
which involves the movement of electric charges
Power plant:
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A power plant is an industrial plant suitable for producing electricity. Modern
society is based on an essential use of electricity, so the production of energy
and, consequently, power plants have a fundamental technological
importance. The power plants produce energy almost exclusively in today's
alternating current, using electric machines called alternators.
Chemical energy
• Chemical energy is energy that varies
due to the formation or the breaking
of chemical bonds of any kind.
• It is deposited in the connections
between atoms within the molecule.
When these connections are broken
(eg when a substance burns), a part
of this energy lives released as heat
and light.
Thermal energy
• Thermal energy is a form of energy possessed by any body that has
a temperature above absolute zero. Thermal energy can be
produced in large quantities simply through combustion, or by
means of nuclear reactions, or by passing electric current through a
wire with low resistance, as in electric stoves and all appliances that
produce heat. The heat sources are : the sun and the subsoil.
Geothermal energy
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Geothermal energy is energy generated by geologic sources of heat and
can be considered as a form of renewable energy.
Geothermal energy is a form of usable energy that comes from the heat
that there is in the deeper layers of the earth's crust. Penetrating
deep into the earth's surface, the temperature gradually becomes
higher, increasing by an average of about 30° C per km in the earth’s
crust.
Energy consumption in the
world
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About 1.6 billion people, a quarter of the world's population, are without
electricity.
Most of this population lives in the developing countries such as Africa and Asia..
About 2.6 billion people use traditional biomass almost exclusively as a primary
source of energy
Mondo
Richiesta energetica
12
13%gas 1%rinnovabili
11%petrolio
19%idro-geo
38%carbone
18%nucleare
2,7
10
miliardi di tep
•
2,5
2
8
6
1,5
2,8
3,6
4,2
1,5
4
2
0
3,7
1996
4,2
1998
4,4
4,5
2000
2002
Energy consumption in Italy:
50
45
40
35
Renewable
Coal
Natural gas
Nuclear
Other sources
30
25
20
15
10
5
0
2008
2009
Renewable energy in Sicily
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Energy needs in Sicily
2003 : 20.571 GWh
2004: 20.972 GWh
2005: 21.406 GWh
Net production in Sicily
2003: 24.387 GWh
2004: 24.618 GWh
2005: 24.796 GWh
Solar energy
Solar energy can be used to generate electricity or heat. The
main technologies used for the transformation of solar energy
are: solar panels; photovoltaic panels;
.
Solar power in Priolo:
Energy is produced from burning mirrors.It is the first system in the
world that functions at night. It satisfies about 4 000 families. The
structure has a feature that makes it unique: it is able to collect solar
energy and preserve it for many hours.It is 5,5 km long. Special tubes
run through 30 000 square feet of parabolic mirrors. It is able to
generate electricity at night or in overcast skies.
Wind energy
• Benefits of wind energy:
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The wind is a renewable resource;
It does not emit pollutants;
It contributes to greenhouse gas reduction .
Hydroelectric energy
• Hydroelectric power is derived from
rivers and lakes, through the
establishment of dams and
penstocks. There are various types of
dams: a center jump will take
advantage of water falling from great
heights available in mountainous
regions. In-river plants are used river
water masses that jump over small
steps. To do this, however, the river
must have a consistent flow.
The water of a lake or reservoir is
piped downstream and its potential
energy is transformed into kinetic
energy thanks to the distributors and
the turbines. The kinetic energy is
then transformed through the electric
generator into electricity.
Why save energy…
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To reduce environmental stressors: energy saving in fact is the
fastest and most efficient instrument in terms of cost to
reduce greenhouse gas emissions, thus improving air quality.
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For international politics reasons -that is to say -to meet the
agreements of the Copenhagen conference, which has set the
target of lowering the average temperatures to 1.5 degrees by
2015.
For economic reasons: because the EU could save at least 20%
of its current energy consumption.
To promote the economic growth in the developing countries.