Video Transcript
Which of the following types of
power station release carbon dioxide into the atmosphere? a) A nuclear power
station. b) A coal power station. c) A gas power station. d) A solar farm. e) A
wind farm.
Okay, so, considering these
five different types of power station, we want to know which ones release this
gas, carbon dioxide, into the atmosphere in the process of generating power. Now, the fact that we’re
talking about releasing a gas into the atmosphere as a biproduct of power
generation means that we’re talking about a certain category of power
generation. We can think in terms of the
broad categories of renewable energy sources and nonrenewable energy
sources. The difference between these is
that if a source is renewable, that means that it is not depleted as it
generates energy, whereas nonrenewable sources are depleted as energy is
extracted from them.
So, for example, if we had an
array of solar panels, panels that take in sun energy and convert it to
electrical energy, we can see that the generation of energy by this process in
no way depletes or diminishes the energy of the source, the sunlight. Generating energy by solar
means, then, is an example of using a renewable source. This distinction between
renewable and nonrenewable energy sources is important when we realize that the
release of carbon dioxide that the problem statement talks about is a result of
a process of combustion, that is, something burning.
The two standard products of
combustion are carbon dioxide, CO₂, and water. Whatever types of power station
release carbon dioxide into the atmosphere will be types that involve some sort
of burning, some combustion process. So, among our answer options
we’ll look for sources that require combustion for extracting their energy. As we go down our list, then,
considering a, b, c, d, and e, we can see that both options d, a solar farm, and
option e, a wind farm, are renewable sources.
The sunlight and wind that
generate energy in these farms, respectively, is not depleted by being used up
to generate electricity. Moreover, getting energy from
these sources does not involve combustion, and as a result, they don’t release
carbon dioxide into the atmosphere. So, we’ll cross out options e
and d from our list of candidates.
Considering option a, a nuclear
power station, we know that this kind of source uses nuclear fission to generate
energy. It’s not a burning or
combustion process, but rather a splitting process, where larger atoms split
into smaller ones, that’s responsible for the generation of power from this type
of power station. Since no combustion is involved
in nuclear power generation, we’ll cross off this possibility as a type of power
station that can release CO₂.
This leaves us with coal and
gas power stations. For both of these types, there
is combustion that goes on; the coal is burned and the gas is burned to generate
energy. As these fuels are burned, they
release the products of combustion, carbon dioxide and water. And therefore, both these types
of power station release CO₂, carbon dioxide, into the atmosphere.