Please enable JavaScript.
Coggle requires JavaScript to display documents.
ENERGY AND ITS TRANSFORMATION (NON-CONVENTIONAL ELECTRIC POWER PLANTS:The…
ENERGY AND ITS TRANSFORMATION
ENERGY SOURCES:
Are natural resources from which we obtain different forms of energy that can be transformed for a specific use. The energy we consume has many different uses:
Household uses:
The operating of electrical appliances, heating systems, hot water systems, heat for cooking and for means of transports, for example.
Industrial uses:
The operating of factories and companies , construction, agriculture and so on.
We can classify energy sources in several ways:
By origin
By use in each country
By availability in nature and capacity of regeneration
By environmental impact
ELECTRICITY:
Is most widely used form of energy in industrialised societes for two reasons:
It can be transported long distances
inexpensively and with very little energy being lost.
It can be easily transformed
into other forms of energy, such as light and heat.
ELECTRIC POWER PLANTS:
Electric power plants are facilities where primary or secondary energy is tranformed into electricity. Once electricity is generated, it must be transported to towns, cities or
industrial parks
.
Electric power plants use an external source of energy to produce electricity. To do this, they rely on a
turbine-alternator system
The
turbine
converts mechanical energy into the rotating movement of a shaft
An
alternator
has a fixed part, called a
stator
, and a moving part, called
rotor
, connected to the turbine shaft. As the rotor shaft moves,
alternating electrical current
is produced on each of the stator´s coils.
TRANSPORT AND DISTRIBUTION OF ELECTRICAL ENERGY:
Electric power plants are usually located far away from the points where the energy is used-for safety reasons, space requirements or physical geographical considerations.
Electricity
cannot be stored
; therefore, it must be transported to consumption centres. This
transport
involves several processes
1.Increasing the voltage to 220.000 V or 400.000 V to prevent significant energy loss, due to the Joule effect
3.Decreasing the voltage at the electricity substations to 3-30 kV
2.Transporting it by high voltage cables attached to towers.
4.Distribution to homes, offices, industries and public facilities. During this stage, the voltage is reduced to 230-400 V.
CONVENTIONAL ELECTRIC POWER PLANTS:
This type of power plant produces most of the electricity that we use. There are three types:
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. The steam that´s generated moves the turbine connected to the generator.
There is another type of fossil fuel thermal power plant
Combined cycle power plant:
Electricity is generated as a result of two combined cycles, a cycle that uses air and gas, and a conventional thermal cycle. During the first cycle, a gas turbine is used that includes a
compressor
. Air is mixed with the gas and is burnt, which generates electricity in the turbine-alternator system. The combustion gases are transported to a boiler, where they transfer their energy to the water during the second cycle.
Hydroelectric power plants:
This type of power plant uses potential provided by the height of the stored water in a dam, converting it into
kinetic energy.
This energy moves the
blades
of the turbine. Deoending on the destination of the water, hydraulic power plants are divided into two types:
gravity
or
pump
.
Nuclear power plants:
This type of plant includes a
nuclear fission reactor
that produces the pressurised
steam
needed to move the turbine rotor.
Uranium
is the main fuel used
Their main advantage is the
high return
on their energy production.
NON-CONVENTIONAL ELECTRIC POWER PLANTS:
The environmental problems caused by conventional power plants have led to the creation and development of
non-conventional
or
alternative energy power plants.
The main
disadvantage
of these power plants is that they generate much less energy, since they use
diffuse
energy sources.
Their
andvantages
are that they contaminate much less than conventional power plants, they renewable sources and they reduce the energy dependence of petroleum and natural gas.
Wind power plants and wind farms:
These power plants use the kinetic energy of the wind to move the blades of a rotor at the top of a tower, this referred to as the
wind turbine
Geothermal power plants:
These plants use the heat found at deep levels in the earth. This heat may reach the surface in the form of steam, gas or hot water. Geothermal energy may be use directly for hot water and heating, and indirectly for the heat generates steam, which produces electricy.
Solar power plants:
These plants use the energy from the sun. There are two types of installation:
photo-thermal
and
photo voltaic power plants
.
Photo-thermal power plant:
In this type of power plant, the heat generated by saolar radiation produces steam that is used to move the rotor in the generator
Photovoltaic power plant:
In these power plants, solar radiation is transformed directly into electricity by panels of
photovoltaic cells.
Biomass thermal power plants:
