3. What is energy?
We can
understand the
term energy as
the ability of
an object to do
a work using an
energy source.
4. Units of Energy
We can measure energy in different units:
- In Joules (J)
- In Kilojoules (kJ), that are used to express larger
quantities of energy (1000 J = 1kJ)
- In Calories (cal), that often measures heat
energy..
- In Kilocalories (kcal), that are used to express
larger quantities of heat.
- Calories and Joules measure different units of
energy:
1cal= 4.18 J
5. Types of Energy
Energy is classified according to how exists in
nature. There are different types:
- Mechanical Energy
-Electrical Energy
-Electromagnetic Energy
-Sound Energy
- Chemical Energy
- Nuclear Energy
- Thermal or Calorific Energy
6. Mechanical Energy
Kinetic Energy:
Is the energy related to motion or it's the energy that
objects and bodies have when they move. It's also
related as the work needed to acelerate a body of a
given mass from rest.
7. Mechanical Energy
Potential Energy:
Is the energy that objects have when they're in a high,
(it's called gravitational potential energy) or when
they're moved from their stable position of equilibrium.
For example, when the water falls, it does a force from
a distance and it does a work, like moving a turbine.
8. Electrical Energy
Electrical energy is the energy associated with the
electric current produced by the movement of electric
charges inside the conductor materials. When they are
connected to a supply of electricity, it makes
electrically powered machines work. Electrical energy
produces effects, like luminous, thermical and
magnetical. Electrical energy can be transported easily.
9. Electromagnetic Energy
Electromagnetic energy is a form of energy
emmited from objects in the form of electrical
and magnetic waves than can travel through space,
such as radio, television, or X-ray waves. Luminous
energy is a type of electromagnetic energy
produced by the sun and artificial lights.
10. Sound Energy
Sound energy is associated with waves
transmited by the air and produced by
vibration objects. We can say that sound
energy is a form of mechanical energy.
11. Chemical Energy
Chemical energy is the part of the energy
in a substance that can be released by a
chemical reaction. It's stored in substances and it
can be absorved during chemical processes.
12. Nuclear Energy
Nuclear energy is the energy released by
reactions involiving the nuclei of atoms. We
transform nuclar energy into electricity in
nuclear power stations.
13. Thermal or calorific
energy
Thermal energy is a type of energy
that comes from the vibratio nof
particles in matter. Temperature
measures the thermal energy of an
object.
14. Power
The power of a machine is the
quantity of work that can do in a
unit of time.
The formula of Power is:
P= W/t
Watts measures Power (P)
Joules express Work (W)
Secounds measure time (t)
15. Energy Sources
Energy sources are natural resources that
provides different forms of energy. This
energy is transformed of specific uses.
Energy sources can be renewable or non-renewable:
Non renewable energy sources: Nuclear
energy, coal, petroleum, and natural gas
Renewable energy sources: Hydraulic
energy, Solar energy, Marine energy,
Geothermal energy, Biomass.
16. Non renewable energy sources
- They come from natural resources that are limited
- They will run out if we continue to use them.
- Regeneration is very slowly because the need millions
of years to form
With non renewable energy sources is easier and
cheaper to produce energy that with Renewable
energy sources.
The main that we use at the moment are nuclear
energy and energy from fossil fuels.
17. Nuclear energy
Production:
Production
It's stored in the nuclei of atoms. It originates from the splitting
of uranium atoms in a process called fission.
There are two kinds:
- Nuclear fusion: is the process by which two or more atomic
nuclei join together, or ''fuse", to form a single heavier nucleus.
This is usually accompanied by the release of large quantities of
energy. It's generated by stars
18. Nuclear energy
- Nuclear fission:
Nuclear fission is a nuclear
reaction in which a heavy
nucleus (such as uranium)
splits into two lighter nuclei
(and possible some other
radioactive particles as well)
by bombarding it with
neutrons.
The energy released in the
fission of one uranium
nucleus is about 50 million
times greater than that
released when a carbon atom
combines with oxygen atoms
in the burning of coal.
19. Nuclear Energy
Transformation:
Nuclear power stations use fission energy.
In a nuclear reactor, nuclear energy is converted to thermal energy.
The thermal energy is used to heat water to make steam which can
be used to spin turbines. The turbines spin electrical generators. A
lot of electric power comes from nuclear power plants.
There are six power stations in Spain, and generate one third of
the total energy consumed.
20. - Origin:
Origin
Coal
About three hundred million
years ago, there was a
climate change in the Earth.
Oxygen dissapeared so all
living beings died and were
buried and fosilised. This
fosil is coal, which is light
and black. There are four
types of coal (depending on
the amount of carbon it
contains: anthracite,
bituminous, lignite and peat.
21. Coal
Transformation:
The coal is first burned in order to transform the chemical energy into heat
energy. That heat energy is then absorbed by water inside a boiler, where it
is converted into steam. The heat energy in the steam flows through a pipe
into a steam turbine where it is again transformed, this time into mechanical
energy that enables the turbine shaft to spin. The mechanical energy in the
turbine is then transmitted by its shaft, enabling it to turn an electrical
generator. And, finally, the mechanical energy is transformed by the
generator into electrical energy.
22. Coal
Extraction:
-Open-cast mines: When the coal is close to the suface, the soil is remove
and the coal is extracted with special machinery explosives.
-Underground mines: When is buried deep below the surface, it must be
mined underground. The shafts and tunnels of the mines provide ventilation
and eliminate the accumulate gas to prevent accidents.
Undergrou
Open-cast mine. nd mine
23. Transport: Coal
In the mine, coal is transported by carts. Then, it's washed and gangue (the useless
part), it's removed. When it leaves the mine, it's transported:
- By sea: in enormous ships (that can weight 500 000 t )
- By land: usually by train (it's economical and they can carry large loads)
- By road: normally for local transport
Uses
-For Energy
- Nowadays its used to:
- Generate electricity in conventional power stations
- For central heating systems
- In the past it was used for street lighting and as a domestic fuel (in the form of
town gas, produced from bituminous coal.
- Other Uses
Other uses are derivates of coal, such as coke, used in steal industry and pich and
tar, used for making roads, plastic, medicines, etc.
24. Origin: Petroleum
Petroleum was formed by the remains of living beings, such as
plants and animals, buried under the sea and descomposed by
bacterial action. It's a liquid substance, and it's and has a lower
density than water. It can be found in porous rocks amd basins
forming oil fields.
Extraction:
Petroleum is expensive and difficult to extract because it's very
deep underground.
1. First, a well is drilled on land or under the sea. Then a
plataform called oil rig is built.
2. Pumps extract petroleum, or natural pressure that causes the
oil rise.
3. The extracted petroleum that contains salt water, rock, mud
and gas is purified.
25. Petroleum
Storage and transport:
The purified crude oil (unrefined oil) is stored in oil tankers and oil
pipelines:
- Oil tankers: It's is a merchant ship designed for the transport
of oil. There are two basic types of oil tankers: the crude tanker
and the product tanker. This dock at special ports where they're
filled and emptided quickly.
- Oil pipelines: are the most efficient method to transport crude
oil and refined products over land. They're lie above the surface
and buried in protected trenches.
Oil tanker Oil pipeline
26. Petroleum
Transformation and uses:
Fractional distillation is
a process carried out in
refineries sto produce
these derivates:
-Liquefied gases, liquid
fuels, fuel oil, light
components and heavy
components.
27. Natural gas
Natural gas is mixture of hydrocarbon gases that occurs with petroleum
deposits, principally methane together with other gases, and is used as a fuel
and in the manufacture of organic compounds. It was formed from
descomposed plants and animals. Is found in underground fields and porous
rocks.
Extraction: Natural gas is extracted by drilling and it's expensive to extract.
Storage and transport:
1. It is transported from gas fields by gas pipelines to a liquefaction plant,
that is an industrial plant where gas is converted into liquid.
2. The gas is converted into liquid form (LNG). This reduces the volume of
gas.
3. It's transported in LNG carries, that are specially designed ships.
4. When the LNG reaches it's destination, it's returned to gaseous state, and
transported again through gas pipelines.
28. Natural gas
Uses:
Natural gas is used to produce thermal
energy, and in thermal power stations to
obtain electrical energy.
29. Renewable energy sources
Renewable energy sources are natural energy
resources which does not have a limited supply.
Renewable energy can be used again and again,
and will never run out
Types:
- Hydraulic energy
- Solar energy
- Wind energy
- Marine energy
- Geothermal energy
- Biomass
- Municipal solid waste
30. Hydraulic energy
Hydraulic energy is what is produced by the water which is stored in
reservoirs and lakes at a high altitude (so that it has gravitational
potential energy). If at a given moment it falls to a lower level, this
energy is transformed into kinetic energy and afterwards into electrical
energy in the hydroelectric plant
Production:
The water is stored in dams
1. When water is released from the dam and falls, it's
potential energy is transformed into kinetic energy.
2. The kinetic energy moves the turbines which rotates an
alternator.
3. The alternator transforms kinetic energy into
electricity.
31. Hydraulic energy
Transformation
To transform hydraulic energy, hydroelectric power stations need:
- Rivers with a lot of water
- Rivers in valleys with a high slope.
Small hydraulic power stations don't contamintate because they're
used to provide electricity to small villages.
Advantages and Disadvantages
Advantages: It is a clean energy source, without waste products
and is easy to store. Also the water stored in reservoirs situated at
altitude permits the regulation of the flow of the river.
Disadvantages: The construction of hydroelectric plants is
expensive and needs large networks of power cables. Reservoirs also
mean the loss of productive soil and fauna due to the flooding of their
habitat. They also cause a decrease in the flow of the rivers and
streams below the dam and alter the quality of the waters.
32. Solar energy
Solar energy is the energy received by the earth from the sun. This
energy is in the form of solar radiation, which makes the production of
solar electricity possible. Life appeared thanks to solar energy
bencause it's necessary for plants to make photosynthesis.
Production and transformation
Solar energy can be used:
- To produce hot water using flat solar thermal collectors. The sun energy
is transformed into heat energy using the collectors.
- To generate electricity using solar panels. The photovoltaic cells
transform sun energy into electricity. This is used for consumption in homes,
busunesses and industry.
- To produce electricity using heliostat fields. The sun energy is used to
heat up water and produce steam. A generator uses steam to produce
electricity.
33. Solar energy
Advantages and disadvantages:
Advantages: Solar energy is a completely renewable
resource.
Solar cells make absolutely no noise at all.
Solar energy creates absolutely no pollution.
Very little maintenance is required to keep solar cells running.
Solar powered panels and products are typically extremely
easy to install.
Disadvantages: The Solar Cells and Solar Panels that are
needed to harness solar energy tend to be very expensive
when you first purchase them.
Solar power cannot be harnessed during a storm, on a cloudy
day or at night
34. Wind energy
Wind Energy is the energy received from the
movement of the wind across the earth. This energy is
a result of the heating of our oceans, earth, and
atmosphere by the sun. It has been used since ancient
to move sailing ships.
Production and transformation
Winds are caused by uneven heating of the atmosphere
by the sun. Wind energy has kinetic energy, and when it
causes the blades of a wind turbine move, they convert
the kinetic energy of wind energy into mechanical
power. Then, mechanical power it's tranformed into
electricity
35. Wind energy
Advantages and disadvantages:
Advantages:
It's friendly to the surrounding environment
-Wind turbines take up less space than the average power station.
-Wind turbines are a great resource to generate energy in remote
locations
Disadvantages:
-Sometimes, the winds strength is too low to support a wind turbine
or wind farm
- Require multiple wind turbines to be built in order to make an
impact.
-Wind turbine construction can be very expensive
36. Marine energy
Marine energy refers to the energy carried by
ocean waves, tides, salinity, and ocean temperature
differences. The movement of water in the world’s
oceans creates kinetic energy, or energy in motion. This
energy can be harnessed to generate electricity to
power homes, transport and industries.
Marine energy can be used:
- Tidial energy is extracted from the tides.
- Wave energy is obtained from the movement
of sea waves.
- Ocean thermal energy is produced from the
difference of temperature between the surface
of the sea and the deep sea.
37. Geothermal energy
Geothermal energy is the thermal energy from the
Earth., and it's stored below the Earth's crust. It
usually go out the earth in the form of hot springs
and geysers and volcanic eruptions. If the
temperature is below 150º, heat is produced and if
the temperature is above 150º electricity is produced
by this process:
39. Biomass
Biomass is biological material derived from
living, or recently living organisms. Biomass for
energy can include a wide range of materials,
such as virgin wood, energy crops, agricultural
residues, food waste and industrial waste and
co-products.
Fossil fuels are also derivated from biological
material, but the vital differennce between
biomass and fosil fuels is one of time scale.
41. Types of power stations
There are different types of Power
Stations according to the type of energy
that they transform into electricity. The
main are:
- Hydraulic Power Stations
- Solar Power Stations
- Nuclear Power Stations
-Thermal Power Stations
-Eolic Power Stations
42. Hydraulic Power Stations
Hydraulic Power Stations use the kinetic or potential energy of
flowing water to produce electricity.
How do they work?
Water in these reservoirs flow down the dam and rotate a turbine.
As the blades of a turbine turn, so do the magnets inside the
generator which is connected to the turbine. These magnets rotate
copper coils and with each rotation, electricity is produced.
Building reservoirs can spoil the landscape and destroy villages, and
ir a dam breaks, it can even provoke a catastrophe. But the
advantages are that producing hydraulic energy is cheap, clean and
non-polluting.
44. Solar Power Stations
Solar power stations use the solar energy that comes from the
sun to produce electricity. Solar energy is one of the most
abundant natural resources.
How do they work?
Using solar panels, light is transform into electricity using
photovoltaic cells.
In heliostat fields, mirror reflect light onto a collector. The
colectors use the thermal energy of the solar energy to heat
water and produce steam. A generator then uses the steam to
produce electricity.
Solar power stations are not very abundant because they're quite
expensive for general use, but they produce unlimited energy
without polluntig.
45. Nuclear Power Stations
Nuclear Power Stations work using the chemical process of
fission, and also the process of fussion. Nuclear reactors
are used to generate electricity.
How do they work?
Fission is a type of nuclear reaction in which, when the
atoms of elements absorb free neutrons, they split into
two or more small nuclei and some free neutrons. In the
process, large amount of energy is released.
Nuclear Power Stations produce a lot of electricity, but
it's very dangerous for the environment and pollute a lot.
They can provoke a catastrophe, like in 2011, in Fukushima.
47. Thermal Power Stations
Thermal Power Stations generate electrical energy from thermal
energy (heat). They use the heat from burning coal, petroleum
and natural gas.
How do they work?
Today, coal is the most common fuel that is used by thermal
power stations. The heat generated by burning the fossil fuels is
used to turn a rotating machinery, most commonly a steam
turbine or a gas turbine that changes the thermal energy into
mechanical energy. The rotating turbine is attached to an
alternator that coverts the mechanical energy of the rotating
turbine into electrical energy.
Thermal power stations can be polluting for the environment.
48. Eolic Power Stations
Eolic Power Stations transform wind energy into electrical
energy in wind farms using wind turbines.
How do they work?
When wind energy causes the blades of a wind turbine to move,
the wind's kinetic energy is converted into electricity.
49. Wind turbines can produce water
A French engineering invented a special wind turbine that can
produce water from thin air, but they're still developing the
capacities.
The wind turbine suck the air that contains water. It extracts
humidity from the air, creating moisture which is condensed and
collected. Then the water is filtered and purified before it can be
consumed.
One turbine can produce 1000 liters of water every day, depending
on the condition. It's enough to provide water from 2000 to 3000
people.
So this wind turbine is very useful in places where there is no
water, like Africa, South Africa and some places in Asia.
Now the wind turbine is a little bit expensive, but it isn't so much
compared with the solutions that it gives.