In the context of increasing concern about
electricity presence without interruption which is an essential need for societies
wants to go ahead in advanced development and because electricity isn’t
generated from the air, it generates from other form of energy .So it is important
to know some basics about energy such as energy meaning, energy types, energy units
and energy today and its environmental impact.
Energy Meaning:
Energy is the ability of a physical system to
do a work on other physical system and all of us should know that in a closed
system energy neither be created nor destroyed, it can only transform from one
form to another form of energy. In other word energy is invariably conserved in
a closed system but the system internal energy is changed as work and heat out
or in of it (first law of thermodynamic).Electricity is an important form of
energy but to generate electricity you need primary source of energy as
electricity is a secondary source or energy.
Energy Types:
Briefly we have two main types, the first
one is called “non renewable energy” like petroleum – coal - natural gas and
the second one is called “renewable energy” like wind – geothermal – solar – hydropower
– biomass - tidal (ocean).
Energy Units:
We can express energy as thermal energy,
mechanical energy and electrical energy (electricity). Energy units of the
three forms are equivalent but in different values as following:
Where:
Energy
|
Thermal
|
Electrical
|
Mechanical
|
|
US
|
SI
|
|||
Btu
|
KJ
|
Kwh
|
N.m=K.g*m2/s2
|
|
Btu: British Thermal Unit - J: joule - N.m
: newton meter - Kwh : kilowatt hour and
1055 KJ = 1055 KN.m = 0.293 Kwh = 1000 Btu.
Electricity:
Electricity is a form of energy results
from the motion of electrically charged particles due to induction, friction
and mechanical changes. Electricity considered as a secondary energy source as
electricity generation is depending on other source of energy which may be renewable
or not renewable.
Energy Today and Its Environmental
Impacts:
Today the vast majority of the energy usage
is generated from fossil fuels and with the increasing of living standards and comfort,
energy consumption is increasing day after day and in the same time fossil
fuels is limited and have much side effects on the environment, So we are in a bad
need of using types of renewable energies stated above.
About the environmental impacts of using
fossil fuels:
1-
Reduce air quality
needed for organisms.
2-
Acidification of the
soil.
3-
Green house effects.
4-
Ozone layer reduction.
At
the end if we want to have electricity without interruptions we need to take
care about primary sources of energy especially renewable one.