“Fusion reactors will usher in a new and brighter chapter of human history...but probably not anytime soon”

Explanation:

Scientists and engineers worldwide are actively working to realize the holy grail of unlimited, clean energy: a functioning nuclear fusion reactor. Current nuclear reactors rely on fission, a process by which very heavy elements like uranium are broken apart into smaller elements; when this occurs in a chain reaction inside a reactor the result is a large amount of heat that can be used to generate electricity. The downside to fission is that the process of splitting the heavy atoms produces difficult-to-manage radioactive waste, and the atomic fuel (uranium, etc.) must be constantly cooled or else a catastrophic meltdown can occur.

Fusion is the opposite of fission. Instead of splitting apart heavy atoms like uranium or plutonium, a fusion reactor fuses very light hydrogen atoms to make another very light element, helium, resulting in a huge amount of energy being released in the process. In order for a fusion reaction to occur the hydrogen atoms must be moving fast enough to overcome the mutually repulsive nature of the protons in their nuclei (similar to how magnets repel one another), thus fusing together to create helium nuclei. This is in fact how the sun works: our sun is simply a lot of hydrogen that is compressed by the sun’s massive gravity. This compression causes the hydrogen nuclei to move fast enough to fuse into helium, resulting in the sunlight and heat that makes life on our planet possible.

A working fusion reactor would literally be a very small replica of our sun. Instead of gravity, a fusion reactor uses immensely strong magnetic fields to compress the hydrogen sufficiently to sustain a hydrogen-to-helium fusion reaction. The engineering challenge of creating such a strong magnetic field near an extremely hot “soup” of hydrogen plasma is exceedingly difficult, but steady progress is being made. It is only a matter of time before energy generation via nuclear fusion becomes a reality.

Why Fusion Matters

When energy-producing fusion reactors are finally realized, they will be a source of literally unlimited clean energy. They will also have significant advantages compared to fission reactors: examples include no radioactive waste, no possibility of a catastrophic meltdown, and hydrogen is abundantly available, unlike uranium. With virtually unlimited fusion energy at our disposable, truly revolutionary projects can be realized:

1. Water desalinization: cheaply producing fresh water from the ocean would greatly help solve the world’s water problems and would be a major step forward to making droughts a thing of the past. The desalinization process requires a huge amount of energy, which would be amply available if fusion power existed. Further, with immense amounts of fusion power at our disposal this desalinated ocean water could be economically pumped over long distances to where it is most needed
2. Unlike the case with wind or solar electricity generation, fusion reactors would not require large amounts of land in weather-appropriate areas to implement. As such, fusion reactors could be placed near any location that requires lots of energy: cities, manufacturing zones, and energy-intensive agricultural areas are examples 
3. Transportation: with fusion power an all-electric transportation infrastructure becomes even more attractive and viable. This would not only mean unlimited, domestically produced “fuel” for electric cars and other vehicles, but also for very high speed trains and subways. There would be a peace dividend as well: no more taxpayer dollars paying to secure overseas fossil fuel supplies
4. Recycling: with unlimited electric energy available in combination with other novel technologies, highly effective and more practical recycling systems could be deployed, thus reducing waste and pollution
5. Space launchers: space launchers based on magnetic acceleration could make getting things into space much more economical, allowing humankind to start an exciting new space age
6. Much more: unlimited clean energy means limitless possibilities to solve problems, achieve widespread prosperity, and improve people’s lives. The only limitation will be our imagination

We Don’t Need to Wait

As exciting as the prospect is of fusion power is, unfortunately it may not become available for at least several decades due to a number of very difficult engineering challenges. The good news is we can already achieve the promise of unlimited clean energy today through solar, wind, geothermal, and tidal electricity generation. Further, modern fission reactors are much safer and easier to deploy than conventional designs. These new types of fission reactors could supplement solar and wind power generation, and could pinch hit for many decades until fusion power becomes a reality.

The time has come to aggressively phase out fossil fuels and start a new age of widespread prosperity based on unlimited clean energy. Fusion will be a crucial part of this exciting new chapter in human history, but let us not wait until it is available to begin the transition—let’s get going now.