The world we live in revolves around the culmination
of various energy sources to operate the daily necessities of living, such as
food, shelter, electricity, transportation and much more. The following paper will evaluate the
conventional energy technologies used as well as alternative energy sources,
and their impact on Earth. Furthermore,
the chemistry behind the functionality of the energy sources will be analyzed.
One of the largest environment-impacting energy
sources used involves fossil fuel burning.
Fossil fuels are hydrocarbons that are produced from the remains of dead
animals and plants. Coal, fuel oil, and
natural gas are common examples of fossil fuels. A hydrocarbon is an organic compound that
consists of hydrogen and carbon. When
decomposed, hydrocarbons provide a large quantity of carbon and hydrogen which,
when bonded, could form chains. The
primary use of hydrocarbons is as a combustible fuel source. Chemistry principles could be used to
describe the burning of methane or the carbon in coal. The reaction: C+ O2 -> CO2 is the basic
reaction of the burning of carbon which provides the greatest energy source. This reaction occurs in coal, natural gas,
and oil, all of which are fossil fuels. Energy
within this reaction is only present because of the solar energy within the
plants, which are then processed for millions of years under the pressure in the
Earth. Carbon molecules in coal are attached,
thus, there is only one C-C bond for every C atom. To determine the efficiency of this
mechanism, one must calculate the energy release from creating CO2. Carnegie Mellon University states that the
net release is 152 kcal/mole of carbon. Therefore,
1 kg of carbon gives approximately 11000 kcal.
The university also states that 44g of CO2 is produced for every 12g of
carbon burnt. The contribution that
carbon dioxide has to global climate change is substantial and is one of the
major problems of fossil fuel economy. To put the environmental impact in
perspective, power plants that burn coal produce more harmful carbon dioxide
than all cars, trucks, planes, and other forms of transportation combined (Fossil
Fuels Affect the Environment,” 2018). Greenhouse gases are contributing to
global warming as the sun’s energy is trapped in the Earth’s atmosphere.
The remainder of this paper will examine the
alternative energy sources from the sun, wind and ocean as these modes could
help reduce the use of fossil fuels. These
renewable energy sources do not emit carbon dioxide into the atmosphere, which
is an imperative step towards helping the planet.
The Sun, which would provide at least another 4
billion years of solar energy striking Earth daily, harnesses a powerful energy
source for electricity and could be one of the best options to combat global
warming. However, for solar panels to be
efficient, a variety of factors must be met.
Majority of solar panels are made with a layer of protective glass over
the cells that sunlight must pass through.
Reflection of the glass is to be minimal, as well, the amount of energy utilized
depends on the angle of which light is passing through. The user also must be aware of the
positioning and angle of the panel upon installation. The panel should be installed so that the
maximum amount of sunlight is shining on it to maximize efficiency. This would include avoiding shade and finding
the optimal position on a roof (Empire Renewable
Energy, 2018). Solar panels function through solar cells
within the panels. A single solar cell
is composed of two kinds of semiconductors called p-type and n-type silicon. Boron/gallium are p-type silicon and is created
by adding atoms as they have one fewer electrons in the outer energy level.
Since boron has one less electron than necessary to form bonds with silicon
atoms, an electron hole is produced.
This is perfect because in an n-type silicon there is one more electron
in the outer level, i.e., phosphorus. Therefore, binding with surrounding atoms
could occur, however, one electron is not included in bonding. The electron is instead allowed to freely
travel inside the silicon structure.
Thus, within a solar cell there is a p-type silicon placed in
conjunction to a layer of n-type silicon. The n-type layer has extra electrons,
whereas the p-type layer is excessively charged with positive holes. Between the layers, the electrons on one side
navigate into the holes of the other side.
A junction is formed, known as the depletion zone. Once the holes are filled in this zone, the
p-type now carries negatively charged ions, and the n-type side carries
positively charged ions. With these oppositely charged ions generated, an
electric field would impede electrons in the n-type layer to fill the holes in
the p-type layer. Upon sunlight striking
a solar cell, electrons in the silicon are released, which leads to the
formation of holes. Having this occur in
an electric field would move the electrons from n-type to p-type. Solar panels are built with metallic wires
which would allow the electrons to move from n-type to p-type by crossing the
depletion zone previously discussed; this generates the flow of electricity (American Chemical Society, 2017).
As the main goal is to reduce global warming
emissions, solar panels do a relatively good job compared to natural gas and
coal. It is estimated that solar power
ranges from 0.08-0.2 pounds of carbon dioxide per kilowatt-hour. This is far less than its counterpart of coal
at 1.4-3.6 pounds of carbon dioxide per kilowatt-hour (Union
of Concerned Scientists, 2013).
Apart from solar energy, hydro is also one of the best
methods of energy source because of its ability to use waves and water currents
to produce electricity. Hydroelectric
power plants utilize a dam on a river to store water in a reservoir. The flow
of water, once the reservoir is released, spins a turbine which then activates
a power generator to create electricity. There are power lines that are
connected to the generator that bring electricity produced to homes. Moreover, hydropower is quite efficient as
there are power plants that could store power, called a ‘pumped storage plant’. Power is discharged from a power grid into
the electric generators. When generators
spin the turbines backwards, it causes the turbines to pump water from the
river/lower reservoir to an upper reservoir.
This is where the power is stored.
To utilize that stored energy, the water is released from the upper
reservoir back into the river or lower reservoir, causing forward spinning of
the turbines and ultimately initiating the generators to generate electricity
(Renewable Energy World, 2018).
The movement of water does not negatively affect the
environment; it is safe and clean, which is why it is the world’s leading
source of renewable energy. Since water
is a sustainable source, it would not run out and could be used over and
over. By using water as energy, there is
no decrease in the volume of water.
However, speeds, flow of water, and sometimes temperature, are changed. To
put in perspective how beneficial hydropower really is, Wisconsin Valley
Improvement Company’s website has some staggering facts. Hydropower prevents the burning of 22 billion
gallons of oil and 120 million tonnes of coal each year. It is such an
efficient way to produce electricity as turbines could convert the 90% of
potential energy of water and gravity into electricity. On the other hand, even the best of fossil
fuel power plants are only 50% energy efficient.
As discussed in this paper, fossil fuels are not a top
choice for energy production. With the
modern development of solar panels and hydroelectric power, it eliminates the
need for other energy production methods that produce harmful greenhouse gases. It is imperative for everyone to promote
renewable energy as it could one day be the sole factor to whether the Earth is
habitable for mankind or not.