Sun in a Box, Fusion and Antimatter Collisions
Most of us are familiar with the fact that conventional resources are finite. We are also aware of some existing clean alternatives such as wind, solar and tidal energy. But each of these come with their own constraints, be it lack of space, money or strain on existing resources. So, on the occasion of World Energy Conservation Day, I will try to provide some insight into new and developing technologies, which can potentially change the entire field of clean energy for the better. However, please bear in mind that a lot of the things said in this article are purely theoretical, for now.
Nuclear Fusion and Cold Fusion
You might have heard about nuclear fission, wherein nuclei of heavy, radioactive atoms are split in order to release exponential amounts of energy. In fact, the fission of uranium 235 is used to generate energy commercially, and provides 9% of the total energy production of the United States! It might be efficient, but it has a major drawback. It produces toxic and hard-to-dispose nuclear wastes such as plutonium-235.
Luckily, there is an alternative, called nuclear fusion. Unlike fission, fusion harnesses the energy from the joining of nuclei at extremely high temperatures. That is also how the sun gets its energy, and that too without the production of toxic waste!
Unfortunately, so far, it has remained non-viable, as it requires temperatures as high as 107 kelvins! The sheer amount of energy needed to start fusion is greater than the energy produced. That is why research is going on in the field of cold fusion, where fusion can be done at room temperature. Scientists around the world are working on a progress called “Ito”, which is a prototype nuclear fusion reactor. It is estimated to cost at least 24 billion US dollars, and might not be completed for at least 17 years! However, if funding continues and this project succeeds, all our energy problems will be solved! For now, all we can do is remain hopeful.
Antimatter is the anti-particle of matter. The exact nature of it is still an enigma, but what is known is that it is real, and can be created in a laboratory environment.
But here is how it ties into our discussion- the energy generated when matter collides with antimatter is huge!
This phenomenon is the actual, scientific definition of one of the most overused words in fiction: “Annihilation”. If 1 kilogram of matter were to be annihilated by 1 kilogram of antimatter, it would produce 1.7 x 1017 joules! To put that into perspective, “Little Boy”, the atomic bomb dropped on Hiroshima had 64 kilograms of weapons-grade uranium on it. It only managed around 6.5 x 1013 joules, which pales in comparison to the aforementioned scenario. Of course, the main concerns are keeping antimatter stable, as even the simplest antimatter, anti-hydrogen disintegrates after 15 minutes, let alone the costs of producing this energy in a safe and economical fashion, and storing it.
Sun in a Box
Enough about making energy. What about storing it?
Lithium ion batteries, although commonly used, are not very efficient. However, researchers from MIT might have a solution! The full name of it is Thermal Energy Grid Storage-Multi-Junction Photovoltaics (TEGS-MPV). It is an insulated graphite silo containing a slug of white-hot molten silicon. According to the researchers, this “sun in a box” could store excess electricity for long periods as heat. So, you would use solar panels to power the grid, make sure there are enough panels to produce excess power during the day. That power gets funneled into the sun box to heat up the silicon core. When the grid needs power at night, a multi-junction photo-voltaic system inside the silo captures light from the glowing silicone to convert it back into electricity. The system would work the same with wind power. This approach is similar to molten salt energy storage. In that system, concentrated light heats salt to about 1,000 degrees Fahrenheit. Then you need to get that heat out as energy, the salt is pumped through a heat exchanger to create steam that spins a turbine. However, the temperature cap isn’t high enough to supply many homes when the sun goes down. The silicon core of the sun in a box could reach 4,000 degrees Fahrenheit or more.
Based on initial small-scale testing, the team estimates a single TEGS-MPV storage tank could store enough power to supply 100,000 homes overnight in combination with solar panels or wind farms.
These are just early tests, but we can certainly have hope that someday these will succeed.
Article written by Edudigm’s student, Kausar De.