The hot sun holds the secret to keeping the planet cool7 min read

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Aishwarya Sivaraman

One of the things that sustain human civilization is energy. We see it everywhere in the form of light, heat, motion, sound, and even chemical energy (think batteries). The most consumed form of energy is heat or thermal energy that comes from burning fossil fuels— known as combustion. Over the last century, we’ve come to know very well that combusting fossil fuels leave behind polluted air that rapidly deteriorates the quality of our environments and leads to so many problems that we can’t even keep track anymore! And this will be the key problem of the coming decades that everyone wants to desperately solve:

How can we create clean energy?

There are many alternatives to clean fuel, the most well-known being solar and wind energy. They are common around the world now as the materials required to develop these technologies become more and more affordable to develop. But scientists have another trick up their sleeve that, if developed, could make energy production almost free of cost and protect our environments from the dangers of fossil fuels at the same time!

This is the process of controlled nuclear fusion.

Nuclear Fission

There are nuclear reactors around the world that use a process called nuclear fission, which is the process of splitting an atom of Uranium using a neutron at such high speeds that it starts a chain reaction of producing more high energy neutrons. The heat from these neutrons is used to heat water which is then used to produce electricity. But fission requires raw materials that are extremely difficult to find, requires a ton of control so the nuclear reactors don’t explode and produce a lot of radioactive waste.

Nuclear Fusion

This is where nuclear fusion becomes the better alternative. The process is exactly the opposite of what happens in fission. In fusion, typically two atoms of hydrogen are fused together at extremely high temperatures and under high pressure. This produces a neutron and a helium atom, releasing massive amounts of thermal energy, several times the amount that can be produced in a fission reaction. 

So why aren’t we using fusion to solve the fossil fuel problem? 

Nuclear fusion is an extremely difficult process to master. The first problem is that the temperature and pressures required to initiate the reaction are so high that it is almost impossible to get the process going and sustain it for long enough that it reaches a tipping point called ignition.

Ignition is the point at which a fusion reaction no longer needs further temperature or pressure regulation to keep the reaction going. The reaction reaches a momentum where the energy it produces is enough for it to continue fusing the by-product atoms it generates. The fusion reaction, in theory, could be self-sustaining forever. 

To picture this effectively, here’s an example of a fusion reaction that we see everyday: the Sun! At the center of the Sun is a massive, uncontrolled fusion reaction that is continuously fusing together hydrogen atoms to produce extremely high thermal and light energy that is sunlight. 

Scientists around the world have been working for decades to solve this problem and find a way to create a fusion reaction that could result in free energy to power the world. Recently, a group of scientists came very, very close to kickstarting a chain reactive fusion at the world’s biggest facility in Lawrence Livermore National Laboratory in California USA. They managed to start a fusion reaction that generated 10 quadrillion watts of power for less than a second before the reaction died out. The reaction managed to produce roughly five times the energy that was used to start the reaction!

Many scientists around the world are trying to figure out how to create the high temperatures that are required to make fusion work. Some are attempting to focus hundreds of high-energy laser beams onto a pair of hydrogen atoms to get them to fuse. Others are using elements that act like fuel, deuterium, and tritium, which are accelerated to speeds that cause the elements to implode and release tons of energy in fusion.

What does that mean for our future?

If we manage to succeed in our efforts to create a sustainable fusion reaction, we may never again experience the terrible pollution that our vehicles now cause. It means better access to cleaner resources like water, better facilities for our farmers, and never again having to experience power cuts on hot summer days.