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Friday, 1 April 2011

Green Sources of Energy: Which Green Energy Source has the X-factor??

If you look at Dutch and probably also German, British and American television, you will notice that these days there are many talent shows, like:
-     X-factor
-     [your country’s name] got talent
-     The voice of [your country’s name]

Only in The Netherlands there are a zillion talent shows.

But what has that to do with an economic blog? This: In these days all non-green sources of energy are in some way under fire:
-     Nuclear energy is now as popular as an alcohol ban during “spring break”. The events at Fukushima showed the world unfortunately that two characteristics of nuclear energy are not under control yet:
o    The uncontrollable energy and radiation outburst of nuclear fuel at moments when all safety systems fail.
o    The nuclear waste problem: what to do with the extremely radioactive, used-up fuel rods. Especially the mixed-oxide fuel rods containing plutonium are so radioactive that it is almost impossible to store them
-     Oil suffers from the enduring problems in the Middle-East and North-Africa in countries like Libya, Syria, Bahrein, Iran, Jemen and Saudi-Arabia. Besides that oil is still polluting the earth heavily: as well during extraction (Nigeria) as during usage.
-     Natural gas is delivered either by Russia, or by some of the same countries in the Middle-East that are suffering from civil unrest nowadays. Those are not the kind of countries you want to be totally dependent on for your energy supply. Gas, however, is the least polluting non-green energy source.
-     Pit coal and brown coal are:
o    extremely dangerous to extract (every year more than 2500 people die in the Chinese coal mines alone)
o    extremely devastating for the landscape in case of opencast mining
o    extremely polluting during usage in power plants.

But still it seems that there is no serious alternative for these kinds of non-green energy. 

That’s why I thought it could be a great idea to put all the green sources of energy in a kind of talent show to find out which green source of energy has the X-factor.


1. Bio-fuel

What is it? Fuel created from the oils or other combustable substances in plants, algae and produce like sugar cane, sugar beet and corn.

Pros
-     Bio fuel is cleaner in usage than oil-based fuels
-     If you use plant species for the extraction of bio-fuel that are not usable for human or animal food and that grow easily on all kinds of surfaces, than it is morally OK to make bio-fuel. A good example are algae that grow in the sea or in special basins and that contain a lot of oil.

Cons
-     These days a lot of human / animal food is used to create bio-fuel, like corn, sugar cane of sugar beet. This is very immoral and can cause starvation in the poorest countries.
-     The cultivation of bio fuels can lead to less farming land being available for food crops, especially when the number of cars in the world is only increasing.
-     Especially in countries like Brasil indispensable rainforest is removed for creating farmland for bio fuel production.
X-factor?
-     The disadvantages of bio fuel make that it doesn’t have the X-factor.

2. Natural hydro-electric power stations

What is it? Power stations that are placed at the fountainheads of rivers and streams. Melting snow and ice supplies water, while gravity makes it possible to drive a turbine.

Pros
-     When these hydro-electric power stations use the gravity effect of water sources in mountains or fjords and don’t change the course of the rivers and streams that rise there, it is excellent to extract electrical energy from this.
-     It is a 100% clean way of extracting electric energy.

Cons
-     Mountains and fjords are very local circumstances. This makes storage and distant shipping of extracted energy very hard. Only the country of exploration itself and its neighboring countries can profit from these energy sources.

X-factor?
-     This is an example of non-polluting production of electrical energy. But due to the predominantly local usability this energy source doesn’t have a large X-factor.

3. Artificial hydro-electric power stations

What is it? Power stations are placed within a dam that creates a massive storage reservoir. When the water escapes from the storage reservoir it drives massive turbines.

Pros
-     It is a 100% clean way of extracting electric energy.

Cons
-     The creation of large storage reservoirs can change the course of rivers and streams in a potentially devastating way. Especially the Three Gorges dam in China is an example of this. It changed the course of the Yangtze river dramatically and caused periods of long drought for villages behind the storage reservoir
-     Once the water has escaped, it often needs to be pumped back into the storage reservoir. On balance this costs more energy than it delivers.
-     The risk of massive floods due to overflow and construction problems in the dams
-     These storage reservoirs and dams are excellent targets for terrorist groups

X-factor?
-     This way of creating electrical energy, although clean, doesn’t have the X-factor, due to the heavy disadvantages.


4. Tidal power-stations

What is it? Power stations are placed in the sea at locations with a big difference between high-tide and low-tide. The massive amounts of waters that pass during the transition from high-tide to low-tide and vice versa drive turbines that gain the energy.

Pros
-     It is a 100% clean way of extracting electric energy.
-     When it happens at places with a naturally big difference between high-tide and low-tide, like the North-west coast of France, it is an excellent way of extracting electric energy.

Cons
-     A big difference between high-tide and low-tide is a very local circumstance. This makes storage and distant shipping of extracted energy very hard. Only the country of exploration itself and its neighboring countries can profit from these energy sources.
-     There is not much experience yet with tidal power-plants. This limits the usability of the technique until the experience is there.

X-factor?
-     This is an example of non-polluting production of electrical energy. But due to the predominantly local usability this energy source doesn’t have a large X-factor.


5. Windmills / turbines

What is it? Everybody knows this.

Pros
-     It is a 100% clean way of extracting electric energy.
-     When it happens at places with constant winds, mostly from one direction, it is a good way of extracting electrical energy. There are a lot of these places on earth, which makes it very easy to place wind turbines.

Cons
-     Wind turbines are very big, very noisy and (i.m.o.) very ugly. And you need an awful lot of them to extract enough energy to supply f.i. a middle-large city of 500,000 citizens or a large factory with them.
o    The total produced energy by wind turbines in The Netherlands was about 2250 MW in 2008. As a large wind turbine produces about 1.5 MW, this means that at least more than 1500 wind turbines were necessary to produce this amount of energy. I think 2500 wind turbines is probably a better estimate.
-     Birds and bats suffer a lot from large wind turbines. Both species are crushed by the blades and besides that bats are vulnerable for the differences in air pressure that are caused by the blades.
o    Bats in US and Europe are extremely important for the removal of insects.

X-factor?
-     The large disadvantages of wind turbines make that wind energy doesn’t have the X-factor.


6. Solar Cells

What is it? Semi-conductors gain electrical energy from the sun rays by using the potential difference between the two layers of the semi-conductor.

Pros
-     Solar cells are a 100% clean way of extracting electric energy.
-     They are easily applicable in small-scale environments
o    Everybody can fit a few solar cells on his house and have a small-scale power plant.
-     Already with a little bit of sun you start to gain energy.

Cons
-     Solar cells are very expensive, as gallium (part of gallium-arsenide) is a rare earth-metal.
-     The efficiency of solar cells is with 32% at most (only the most expensive solar cells have this efficiency) very low.
-     Storage and usage of solar energy during night is very difficult.
-     Usage of these solar cells needs to be heavily subsidized to make it affordable for normal people

X-factor?
Solar cells have a little bit the X-factor, because of the small-scale, low-threshold possibilities. However, the little efficiency and high production cost are serious disadvantages.


7. Concentrated Solar Power

What is it? Large amounts (hundreds) of electrically controlled mirrors, called Heliostats, cluster the rays of the sun at one central point. At this point a fluid (seawater) is heated up to superheated steam and this steams drives a turbine. The temperature in the central column can reach a maximum of 1000 °C (1,832 °F) for the largest plants.The PS10 Solar Power plant in Spain produces about 11MW of energy (source: Wikipedia)

Pros
-     This is a 100% clean and quite effective and efficient way of producing electrical energy.
-     Especially in deserts and other unhabited, extremely warm and sunny places it can deliver a lot of energy.

Cons
-     Deserts and other places with much sun and virtually no clouds are very local circumstances. This makes storage and distant shipping of extracted energy very hard. Only the country of exploration itself and its neighboring countries can profit from these energy sources.
-     The ultra high-tech mirrors make it a very expensive technique
-     The mirrors make it also a very vulnerable technique: sandstorms, hailstorms and gales / storms can create havoc under the mirrors. The time necessary to rebuild this mirror configuration after a storm is substantial.

X-factor?
For me this technique has the X-factor, although it is nowadays very expensive and has the disadvantages of needing a special environment. But there is a lot of desert all over the world and the producing techniques for the mirrors will become much cheaper.


8. Geothermal energy

What is it? In places where the earth's crust is very thin (a.o. Iceland, the Canaries, Alaska and near vulcans in general), the temperature of molten lava / magma is used to heat up water into steam. This steam can drive massive turbines and generate a lot of energy.  

Pros
-     This is a 100% clean and quite effective and efficient way of producing electrical energy.
-     The earth is an inexhaustable source of heat energy and this makes the supply of Geothermal energy in theory limitless.
-     This technique can create energy 24/7 throughout the whole year. It never has to shut down, in contrary to solar energy.

Cons
-     Places with a very thin earth’s crust are also very local circumstances. This makes storage and distant shipping of extracted energy very hard.
o    The advantage of this technique, however, is that you can create energy in such great quantities that the loss during storage and shipping can be much smaller (advantage of large-scale efficiency)

X-factor?
For me this technique has the highest X-factor, due to the enormous pro’s. The shipping of energy is still a problem, but the development of batteries and capacitors might improve in the future, making it easier to ship electrical energy. As the generated electrial energy is (in theory) the highest here, the efficiency is probably also the highest.

Summary
These are not the techniques to solve the earth’s energy problem for the next 20 years. Fossile and nuclear fuel, although detested by many people, are unfortunately the fuels of the near future.

But especially geothermal energy and concentrated solar power are promising techniques, that definitely have the X-factor.

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