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Energy and its transformation - Coggle Diagram
Energy and its
transformation
1 Energy source
Ho u s ehold uses: the operating of electncal appliances, heating systems, hot water systems, heat for cool.ing and for means of transport, for example.
n d u stnal uses: the operating of factones and companies construction, agnculture and so on.
Energy sources are natural resources from which we obtain different forms
of energy that can be transformed for a specific use
2 Electricity
Electricity is the most widely used form of energy m mdustnalised socieues for two reasons
I t can be easily transformed into other forms of energy, such as
light and heat.
It c an be transported long distances inexpensively and with very
httle energy being lost
2.1. Electric power plants
Electric power plants are facilities where pnmary or secondary energy
is transformed into electnmty, Once electricity is generated, it must be transported to towns, cities or industrial parks.
Ho w an electric power plant work
Electncal power plants use an external source of energy to pmduce
electncity To do this, they rely on a turbine-alternator system.
Th e turbine converts mechanical energy into the rotating movement
of a shaft
An a lternator has a fixed part, called a stator, and a moving part,
called a rotor, connected to the turbine shaft
2.2. Transport and distribution of electrical energy
Elec.tnc power plants are usually located far away from the points where
the energy is used — fur safety reasons, space requirements or physical and geographical considerations.
Electncity cannot be stored; therefore, it must be transported to
consumption centres This transport involves several processes
Inc reasing the voltage to 220 000 V or 400 000 V to prevent signif«.ant energy loss, due to the Joule effect.
Tr a nsporting it by high voltage cable~ attached to towers
Dec reasing the voltage at the electncity substations to 3-30 kV
D i stnbution to homes, offices, industnes and public faolities Dunngthis srage, the voltage is reduced to 230-400 V.
3 Conventional electric power plant
3.1. Nuclear power plant
This type of plant tm.ludes a nuclear fission reactor that produr.es the
pressunsed steam needed to move the turbme rotor. Uranium ts the main fuel used.
Their main advantage ts the high return on their energy producuon
3.2. Fossil fuel thermal power plants
At this type of power plant, water is heated in a boiler by the heat
generated from the combustion of a fossil fuel, usually natural gas or coal. he steam that's generated moves the turbine connected to the generator
Combined cycle power plan
fectnctty ts generated as a result of two combined cycles, a cycle that uses air and gas, and a conventional thermal cycle Dunng the first cycle,a gas turbine is used that includes a compressor. Air is mixed with the gas and is burnt, which generates electncity in the turbine-alternator system. The combustion gases are transported
to a boiler, where they transfer their energy to the water dunng the second cycle.
This type of power plant performs better than those with only one cycle.
3.3. Hydroelectric power plants
This type of power plant uses the potential energy provided by the
height of the stored water in a dam, converting it mto kinetic energy.
Tlus energy moves the blades of the turbine Depending on the destination of the water, hydraulic power plants are divided into two types, gravity or pump.
4 Non-conventional electric power plant
The environmental problems caused by conventional power plants have
led to the creation and development of non-conventional or alternative energy power plants.
T h emain disadvantage of these power plants is that they generate
much less energy, since they use diffuse energy sources
The ir advantagesare that they contaminate much less than
conventional power plants, they use renewable sources and they educe the energy dependence of petroleum and natural gas.
4.1. Wind power plants and wind farms
These power plants use the kinetic energy uf the wind to move
the blades of a rotor at the top of a tower, this is referred to as the wind turbine Wind farms are a clean form of generating electnmty However, they
can only be instafled in plat.es with appropnate wind conditions The amount of power generated depends on the size of the instaflation
but it's usually between I MW and 10 MW.
4.2. Solar power plants
Photo-thermal power plant
In this type of power plant, the heat generated by solar radiation produces steam that is used to move the rotor in the generator.To do this, they use special mirrors, called heliostats,that reflect sunlight and concentrate it at one point, where t reaches a high temperature.
Photovoltaic power plant
In these power plants, solar radiation is transformed directly into electncity by panels of photovoltaic cells. These power plants consist of large areas of photovoltaic panels. There are also isolated power plants that are very small in size, which
are used to supply electricity to home~ in rural areas.
4.3. Geothermal power plants
hese plants use the heat found at deep levels in the earth. This heat
may reach the surface in the form of steam, gases or hot water. Geothermal energy may be used directly —for hot water and heating,
industnal use and so on — and indirectly —the heat generates steam, which produces electricity.
4.4. Biomass thermal power plants
Biomass consists of all organic compounds that are produced through natural processes They may come from the following sources.
Fo r estry and agricultural waste.
pecific crops, such as sunflowers and cougar beet.
yraste fromagri-food industries
Biomass Is sublected to different physical and chemical processes in order to produce fuel such as charcoal, alcohol or biogas. This type of fuel Is burnt at biomass power plants. The steam that is generated moves the turbine.
4.5. Ocean power plants
These power plants use the energy from the seas and the oceans. The
concept is to use three types of energy from the sea.
Th e mechanical energy from thetides.
The mechanical energy from the waves.
The energy from the ocean's thermal gradien
5 Environmental impact
The building and operating of an ejectncai power plant results in an ecological change in that region This is due both to the construction of the necessary infrastructure and the waste that this activity generates.
5.1. Environmental impact assessment
As part of a technicaj proiect, it's mandatory to carry out an environmental impact assessment to find out what changes it would
provoke in the environment. An environmental study must also assess both the economic and social
consequences of the project in the area, to decide whether or not to go ahead with the plan. The main characteostii.s of each type of power plant and the impact
they have on the environment are shown below:
5.2. Environmental impact
Energy consumption is preceded by a long process, consisting of several
stages, each ol which has an environmental cost.
Extraction of natural resources
he exploitation of fossil fuels and nuclear power means the depletion f resources, which makes it necessary to find new ones. Fuel extraction processes are sometimes harmful to the environment. In particular, timber extractron has led to the disappearance of large areas of
forest, a process that is continuing even today.
Fuel transpor
Oil is transported by means of oil pipelines and oil tankers.
Oil pipehnes can suffer accidents caused by nature or human error, which result in uncontrolled spills. Oil tankers can have accidents at sea, with the nsk of oil spills. Some
spills have caused oil slicks that have taken years to clean up and dissipate and have aftected the lives of many plant and animal species
Electricity generation
La r gehydroelectric power plants require water reservoirs covenng arge areas, which protoundly change the natural cycle of overs,
flood large land areas and destroy ecosystems, in addition to mcreasing the nsk of accidents.
C onventional thermal power plants can cause numerous problems
and environmental hazards
Th ey produceair pollution — suspended particles, CO, heavy
metal molecules and so on.
They emit large amounts of COa which increases rhe greenhouse
effect.
Th ey emit sulphur dioxide and nitrogen oxide that causeacid
rain, which is very harmful to the environment
The water used in the cooling system is returned to ihe environmem
while it'ssull warm, which affects both animal and plant life
N u clear thermal power plantsare accompanied by the nsk of
nuclear accidents and the problem of nuclear waste, some of which remam dangerous for thousands of years.
Final energy use
Thc fuels we use in vehicles and heating systems emit gases and
part«.les similar to those generated by convenuonal thermal power plants. Lvhen we turn on an electric appliance, we' re consumrng energy that
has already caused several environmental problems dunng its extraction, generation and transportation.
5.3. Waste treatment
To reduce the waste generated by thermal power plants, as well as their effects, several measures can be taken.
In stall specialfilters on the pipes at the power plant to capture some of the gas pollutants
Use coal with a low sulphur content, to reduce acid ram.
Ma intain and increase the size of large forested areas, since they absorb carbon dioxide.
Waste from nuclear power plants is stored in drums with thick
~ide~ that do not let the nuclear radiation escape These are then stored in ocean trenches and underground. The use of ocean trenches has its own problems, because there's the nsk
of the drums c.urroding and the radioactive matenal leaking out of them.
5.4. Some solutions
Below is a summary of different possible solutions to alleviate some of
the environmental problems descnbed
Efficiency
en ergy effiaency policies increase effiaency of everyday appliances and devices.
no ticeably reduce the energy we consume.
Examples
ow fuel consumption cars
electnc cars
better home insulation
Energy diversification
use of renewable energy sources
is fundamental.
ob jective is to produce a large
part of our eiectnqty through alternative power plants.
Energy savings
essenual to reduce the consumption of ag forms of energy —without seriously affecting qua hty of kfe.
ad opuon of more environmentally fnendly habits
Examples
usmg pubic transport or bicycles
hanging consumption habits
