My CAJ is about environmental technology.
This whole semester I read about new ideas and concepts that could help to minimize
or reverse the negative impacts of humans living on Earth because that is what environmental
technology is all about. Humans have done harmful things in the past and are
still doing it, like for example exploiting every last drop of crude oil and
burning it, which pollutes the atmosphere. Environmental tech wants to find technologies
that serve the same purpose but without harming the environment. I found many
concepts that seem very promising, like solar energy, infrared energy and also
a cleaner form of nuclear energy. As all these technologies are quite new and
have not been tested for a long time, it is always possible that they have
negative consequences, as well. However, their whole purpose is to be
environmentally friendly and if researchers realized that there was something
wrong, they would correct it as fast as possible. One thing is sure, however: It
is better to generate energy by letting the sun shine on a solar cell than
digging for fossil fuel and the burning it. Of course, new technology is always
expensive and rare but if enough people buy it and if there is enough demand,
technology will get cheaper and easier to get and there is the possibility of
the government paying for parts of it. When most people have an electrical car
it will seem just normal and people will drive on solar roadways is if it has
always been that way. Environmental technology may not be perfect but it is the
step in the right direction to safe humanity and this planet.
Alexandrah
Montag, 23. Juni 2014
Samstag, 21. Juni 2014
CAJ 12 - Ethical Issues concerning Environmental Technologies
We discussed in class, what ethical
problems could arise from the implementation of each students CAJ
topic. After this lesson and the assignment about ethical issues, I
often thought about what I might have forgotten or what else might be
relevant. This resulted in three ethical issues that seemed
particularly important to me.
The first and probably most obvious one
is the uncertainty if what we are doing is better than what we did
before. What I mean with this is that new technologies like solar
panels and biomass energy are trying to make up for the damage done
by fossil fuels and other harmful human technologies. However, soon
after the introduction of solar panels, it was clear that solar cells
in this form were harming the environment as well because they used
up a lot of energy and rare natural resources in their production.
What if there are more mistakes like that in the new technologies we
are using now? Maybe there are disadvantages we cannot foresee and
what if it is too late when we have finally realized what they are?
Secondly, if there is going to be real
change, politicians have to make decisions. We all know that hard
decisions are not their strength. But let us say that there is one
politician, who is tough and smart and has decided to change
something in the world. He decides that fossil fuels will run out in
the next couple of years anyway and that we need alternatives right
now. That is why he signs a law that prohibits the use of fossil
fueled cars because there are so much better electrical cars that
everybody could use. After his signing the law, the whole country
would be furious and in the next election no one would elect this
politician again because all his opponents would promote the cheap,
old fossil fueled cars. The new legislation would simply reverse the
law and everything would go back to normal but without the smart
politician.
The third issue is the availability of
environmentally friendly technology. Let us take a family of the
working class. There is a single mother with three kids between the
ages of three and eight. The money is scarce as it is and now you
tell this woman that she can not use the second hand car she has been
using for the past couple of years because it pollutes the
environment too much. How is this woman supposed to afford a new
shiny electrical car? No government will be able to pay for every new
car that has to be bought and that means that people are on their own
and have to pay themselves if they want to drive a car at all.
Montag, 16. Juni 2014
CAJ 11 - Overview
As the CAJ project comes to its end quite
soon, I would like to summarize what I have learned so far and what I have
written about. As environmental technology is a very wide field of study, I
could not nearly include everything there is to say or to write about it.
However, I have tried to write about the most promising new technologies and
how they could help us. In the end, I focused especially on solar energy
because there is so much going on in this field right now and because some of
the most promising concepts were developed there.
Solar cells are not only great because they
function with the free energy of the sun but also because there are so many
potential applications. One of the best concepts is Solar Roadways, in which
normal asphalt roads would be exchanged with solar panels. You could drive on them,
recharge your electric car and write warnings on a road that is never wet.
There also is a new material for solar cells, called Perovskite that can not
only absorb light but also emit it. Furthermore, the third generation of solar
cells, the organic solar cells combine almost every advantage of solar power without
real disadvantages. They can be produced cheaply, without the use of rare
materials and use little energy in their manufacture. Solar power can also be
harnessed in Space, where there is enough space available and where the power
of the sun is even stronger.
Another concept which can be combined with
solar energy but can also stand by itself is infrared energy. Researchers have
found out that it is also possible to generate energy through temperature
differences. So, it would be possible to collect energy when heat leaves a
surface. For example, solar cells could generate energy by collecting light
during the day and leaving infrared light during night.
A more controversial topic is nuclear
energy. Everybody knows that this energy can be dangerous but there are ways to
generate energy quite safely. The famous fusion reactor has never really worked
and there still has to be more research done but the fusion-fission hybrid
reactor could actually work pretty safely and without a lot of radioactive
waste. Of course there are ethical questions to be raised but nuclear energy
could be a technology of the future.
Montag, 9. Juni 2014
CAJ 10 - Three Generations of Solar Cells
In search of potential weaknesses or
disadvantages of solar cells, I ended up at the website of the
Technical University of Denmark. In their online course they defined
three types of solar cells, from the first generation to the third. I
will now explain the advantages and disadvantages of each of them:
First generation – Silicon Solar
Cells:
The first solar cells were made of
crystalline silicon and are what everybody has in mind when thinking
of solar cells. They are thick, rigid, heavy and very inefficient.
The materials they use are very expensive and their production
consumes a lot of energy. That is why they were only used when really
necessary, where the price of the energy was not important like in
space, on satellites.
Second generation – Thin Film Solar
Cells:
The next generation of solar cells was
much lighter and easier to produce. Instead of building such big
cells like the first generation, the solar cell was now a thin film
on a carrier substrate. A popular example of second generation solar
cells is the amorphous silicon solar cell. It solved most of the
problems the first generation had. The manufacturing temperature was
much lower, the energy consumption in general was low and the
materials were not as expensive. However, with these advantages came
some inherent problems. They were not as stable as the older ones,
suffered from bad contacts, sensitivity to the atmosphere like water
and oxygen and a decay in performance.
Third generation – Organic Solar
Cells:
The new generation of solar cells are
the organic ones. They can be produced at even lower cost and
temperatures and use even thinner films. There is an indefinite
number of materials and ways they can be built. Moreover, they
operate at an average 10% or more efficiency rate, are extremely
thin, use very little material and can be manufactured even faster
than the second generation. The only potential problem with them is
that they can also be unstable like the thin film solar cells. Other
than that, there lies a huge potential in this third generation.
This already answered part of my
question. I know now that there can be solar cells, which are not
especially environmentally friendly because they use much energy and
materials when being produced. However, with this third generation,
this problem is solved and solar power really seems so be one of the
very best renewable energy sources.
Sonntag, 1. Juni 2014
CAJ 9 - Solar Power Satellite
I have already written quite
a lot about solar energy and the different new possibilities and
materials. In May the Japan Aerospace Exploration Agency (JAXA) has
announced that their goal was to build a solar power satellite that
would generate as much energy as an ordinary nuclear power station
does. This solar power station would then orbit the earth and would
collect solar energy 24 hours a day because of two huge mirrors to
get the sun at every angle. They say that this could be achieved
within 25 years. While there are clearly some issues still to be
addressed, they have managed to solve the main problems like wireless
power transmission over such a long distance. The current solution to
this specific issue are microwaves because they do not get blocked by
the atmosphere and because the power conversion into electric energy
from microwaves is already very efficient. For Japan this is a
logical step because the country has no fossil fuels to exploit,
space for renewable energy is scarce and because of the accident of
Fukushima nuclear energy does not seem to be the right solution
anymore. The plan is very ambitious and there still has to be more
research done, for example in the field of possible materials, but if
Japan succeeds in doing this, many science fiction movies would come
to life.
Mittwoch, 28. Mai 2014
Photography Project - How Instant Photographs Work
How do normal cameras work?
To understand instant photography, one
first has the know the basics of conventional photography. Normal
cameras project the image onto the film, which then has to be
developed externally. The film needed for normal pictures consists of
a plastic base which is coated with three layers of light-sensitive
silver compound. Each of the three layers reacts to a different light
spectrum. The top layer is sensitive to blue light, the middle layer
to green light while the bottom layer reacts to red light. When hit
with light, each of the layers react to the light and form metallic
silver in the according layer. This chemical record is then developed
with the help of chemicals called developers.
What is the difference between this and
instant photos?
Instant photographs develop the
photograph inside the camera itself. To facilitate this, special
instant film is required, which is loaded into the camera. Each of
these films results in a print, just like paper that is loaded into a
printer.
How does instant film work?
Instant film consists of the
conventional three light-sensitive layers and special additional
layers for instant photography. Under each of the three color layers,
there lies one developer layer. On top of these layers, lie three
more layers: the image layer, the timing layer and the acid layer.
All these layers together sit on top of a black base layer. There is
one more layer, which sits between the light-sensitive layer and the
image layer. This layer contains the reagent, which together with the
reagent material breaks loose the chain reaction that results in the
developed photograph. At first the reagent material is collected at
the border of the film, but when the picture is snapped, the film is
passed through rollers, which spread the material out into the middle
of the film. As a consequence the reagent reacts and the chain
reaction starts. When the chemicals have taken full effect the
picture will appear on the film.
[332 words]
Montag, 26. Mai 2014
CAJ 8 - Online Course!
There is something even more interesting.
There is an online course about organic solar cells. I have never done such a
course, but it is free and it starts on June 2nd. I already signed
up to take it, even though the CAJ will be near its end by then. I am thrilled
to see what this course will look like and what I have to do in order to pass
it. Here is the link to the online course, which is organised by the Technical University of Denmark:
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