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Fusion Energy
The process that powers the sun and the stars.
Fusion could help produce very large amounts of renewable energy in the upcoming years. Currently, only 10.4% of the energy consumed worldwide is renewable according to the BP Statistical Review, a British oil extraction, refining and sales company. This means that 90.6% of the energy we consume nowadays will have to be replaced in the near future.
Some people believe that nuclear power will be more than enough to cover future energy needs. Nonetheless, it is not considered a renewable energy since it requires uranium, a heavy metal which exists in limited quantities on our planet. The Uranium Peak will occur in 2040 if we continue to mine it at the current rate.
So how can we produce energy without these resources? We can use renewable energy sources such as wind, water, fission, or even the sun. However, the ideal source would be fusion. It would not take much space, be inexhaustible, and would not release carbon or radioactive waste into the atmosphere.
In the future, energy will be produced thanks to our knowledge. We need to learn how to use renewable energy sources, and how to convert new energies quickly and efficiently in order to exploit them.
How do we get energy out of fusion?
The most stable nucleus is iron, right in the middle of the periodic table. Less stable atoms such as uranium tend to lose or gain electrons in order to resemble iron. In fact, Uranium which is relatively large compared to iron often splits, while smaller atoms fuse together to achieve this. That is what we call the process of fusion.
It is a nuclear reaction in which two light atoms fuse together in order to produce a heavier nucleus while releasing a certain amount of energy. This energy, called fusion energy, is mainly released in the form of heat.
As predicted by Eddington, fusion is present in stars. At their core, hydrogen atoms combine to form helium, which turns into carbon, which then turns back into oxygen. This is a complicated process because it requires high temperatures (of 150 million degrees Celsius).
The fusion reaction which scientists are trying to achieve involves two hydrogen isotopes : deuterium (heavy hydrogen obtained from mother liquor), and tritium (which does not exist in nature). These two atoms are charged and repel each other. However, when they are brought close enough, a strong interaction takes place and they fuse into helium 5, releasing a lot of energy and a neutron.
It is possible to obtain tritium out of lithium 6 and neutrons. That explains why this type of fusion is renewable : the neutron produced after each fusion can be reused with lithium 6 to produce tritium. The problem is that the process requires a temperature of 150 million degrees… The heat excites the atoms in gaseous form, causing them to collide and fusion with one another.
If this type of fusion can be carried out, we will have enough deuterium atoms to produce energy for everyone for the next 30 million years!
For that, we would need to keep gas at a temperature of 150 million degrees! It seems impossible although it has already been done using a magnetic field and what is called a magnetic torus-shaped bottle. In fact, in 1997, the World’s biggest fusion experiment took place at JET and we were able to produce 16 megawatts of energy. To give you a better picture of what that number represents, 200 tons of uranium is normally required to produce just 1 megawatt.
In conclusion, fusion is definitely possible. What is still unkown as of today is when we will be able to convert fusion energy into electricity. Scientists predict that this will be possible by 2040.
