There are also sources of energy to be found
in the organisms around us. There is a
certain type of bioluminescent - “glowing” -
jellyfish, the Aequorea Victoria, which contains
two proteins that cause its bioluminescence. One
of these proteins, the green fluorescent protein
(GFP), can be used in a photovoltaic device to
produce electricity. When the GFP is placed
between aluminium electrodes and is exposed to
ultraviolet light, the protein will absorb photons
and emit electrons, which then generate
electricity. This use of GFP could be considered a
cheaper alternative to Grätzel cells (a type of
dye-sensitized solar cell), as the GFP could act in
place of the dye used in these cells. Using the
GFP instead of the dye currently used in these
cells would be beneficial because the GFP does
not require any additional substances to be
added before being placed on the electrodes,
whereas the currently used dye does, so using
the GFP would cut costs and be a cheaper way of
generating electricity. An application of this use
of GFP to generate electricity is a biological fuel
cell which can generate electricity without the
use of sunlight. Instead, light emitted from
chemicals from the second protein, an enzyme
(luciferase) found also in fireflies and sea
pansies generate electricity without the need for
sunlight. This would be extremely useful as it is
proposed to be used to power devices embedded
within living organisms, which have functions
such as diagnosing diseases.
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Another type of organism that can be a source of energy are microalgae that convert sunlight, water and carbon dioxide
into chemical energy. These algae can then store energy in the form of lipids such as natural oils, and these oils can be extracted
and converted into biofuels. Some of these algae can produce up to 60 times more oil per acre than land-based plants, all of
which could be converted to biofuels and used to power cars, trains and various other machines that rely on gasoline or diesel,
although this is not currently widely used due to the high production cost of microalgae-based fuels. The process of extracting
oils from microalgae and converting them to biofuels involves breaking down the cell structure of the algae using sound waves or
solvents and refining the oils into biofuels. However, this is still a viable alternative method of generating power, although it may
not be on a large scale.
Whilst these sources of energy and their uses may not currently be well-known or used on a large scale, we can see that various
alternative sources of energy do exist, and hopefully should help to shift our reliance on fossil fuels to alternative methods of
generating power in order to create a more sustainable future.