When I was little, I loved watching sci-fi movies and playing games with flying cities, spaceships that traverse the universe and technology that looks like magic.
As you know, none of these things have happened yet. But why?
Even though I write this on my laptop at night, heating my room using electricity coming from a complex electrical grid, we are nowhere near technologically advanced as the common depictions in science fiction or the dreams I had as a little boy. And energy is probably the biggest reason why we can’t yet live in the skies. It is a huge constraint for human imagination and ingenuity.
So, how can we change that? How do we make little Pete’s dreams a reality?
A tiny Sun.
In the future, there are going to be many small Suns all over the Earth. And we’ll use them to power enormous machines, build grandiose structures and conquer the solar system and beyond. Everyone can have a tiny Sun in the future! But wait…what…how?
I’m sure you’ve heard about nuclear energy. But did you know that there are 2 types of nuclear reactions?
The first is Fission, and this is what we already use around the world. Fission has a pretty bad reputation in general and that’s probably the reason why it amounts to only 10% of global energy production today. But how does it work?
Scientists take a heavy radioactive material, usually Uranium-235 and split its atoms by hitting them with neutrons. After the atoms break apart, they emit a lot of energy and other neutrons. These neutrons then go on to hit the next atoms and the chain reaction begins, bringing us the energy we need.
Even though it emits no greenhouse gasses, Fission is not a perfect energy source. Once the reaction has started, it’s an expensive and difficult challenge to keep it under control and the end result is radioactive waste which is extremely dangerous for thousands of years. Oh, and then there’s the potential meltdowns. Everyone knows about those because of the disasters at Chernobyl and Fukushima. Mistakes happen, unfortunately.
Fission is interesting, yet it seems the world isn’t willing to explore it more. The industry is plagued by politics and concerned critics. There are some interesting developments in Fission, but I’ll keep them for another post.
It’s time to see the second nuclear reaction. It’s almost like magic.
We’ve known about Fusion since the 1930s when it was discovered as the energy source of the Sun. Ever since, scientists around the world have been looking for ways to replicate the process here, on Earth.
In Fission, atoms split apart. In Fusion, atoms merge together. And although that might sound easy, it’s far from that. The Sun does fusion reactions constantly, combining Hydrogen at enormous density and temperature. But replicating that process here has turned out to be the greatest scientific challenge...ever.
So where do we begin? The fuel.
Most scientists agree that we are likely to use two Hydrogen isotopes -Deuterium and Tritium. Deuterium is harmless and virtually inexhaustible - it can be distilled from all forms of water. In a cubic meter of seawater, there are 33 grams of Deuterium. It’s basically everywhere!
Tritium, however, is a different story. It is a fast-decaying radioelement of hydrogen which occurs only in trace quantities in nature. There are only 20 kilograms of this material globally and producing it is rather hard. On the flip side, we only need tiny quantities and scientists believe we can produce Tritium during the Fusion reaction itself, thus making it a self-sustainable process.
Why is this fuel special? Well…the energy output of 1kg of fusion fuel theoretically equals 1 million kgs of fossil fuels burned. Let me repeat. 1kg = 1 MILLION KGS. It’s insane.
Once we have both elements, we have to get them to fuse. And here comes the real difficulty…
Since we don’t have the luxury of the extreme pressure created by our Sun’s gravity, we have to do something very different. In order to get these elements to merge, we have to create the hottest spot in the Solar system, maintaining temperatures of at least 100 million degrees Celsius. And will you know it, a reactor in China just reached this impressive milestone! That’s more than six times hotter than the Sun itself. Crazy, right? We’ve artificially created the hottest place in our Solar system. And that’s just the start.
Not only do we have to maintain that temperature, but we also have to keep the elements (which have turned into immensely hot plasma) magnetically confined in order to keep the reaction going and to protect the reactor walls from being melted. Scientists are currently fleshing out many different reactor designs, but the most popular is called the Tokamak. And to little Pete’s enjoyment, it looks like something straight out of a sci-fi movie:
Let’s say we make it. How will Fusion change our lives?
It’s interesting to think about the impact Fusion will have on humanity because it is a topic worth a whole novel itself.
Our whole civilization runs on energy. The food, water and heat that you need to live a comfortable life currently cost a lot of energy to be produced and brought to you. With fusion, fresh and clean water will be available EVERYWHERE as desalination plants become cheaper than ever and we turn massive amounts of saltwater into drinkable water. We could eliminate thirst, hunger, even poverty.
The cost of mining raw materials, refining and creating products will instantly drop by a massive amount. We might no longer require folks to work in terrible conditions to dig coal from the earth. Are you worried about pollution and CO2 emissions? Stop worrying anymore, because Fusion is cheap, clean and emissionless. Enormous projects like reforesting Sahara? Yeah, no problem. We can do that with Fusion. This really is a technology that will transform humanity in ways hard to imagine today.
Fusion will also be a big boon for space exploration. Currently, the biggest constraint is the huge cost - getting anywhere outside the Earth costs billions of dollars. That’s why only until recently, this has been an industry dominated by governments. The price is high for a variety of reasons, lack of reusability being one, but the biggest is the limited payload capabilities of modern rockets. Generally, 90% of a rocket's weight today is the propellant itself. However, compared to any chemical reaction, nuclear fusion provides far more energy per unit of mass, thus allowing a fusion-powered spaceship to carry much less fuel and a bigger payload. If we control the energy of the fusion reaction well, we can accelerate the propellant out of the ship at tremendous speeds. Fusion-powered ships will be capable of feats unthinkable today - a manned craft could be sent to Europa and Jupiter in a few hundred days, or an unmanned probe could reach other stars in centuries rather than millennia. Trips to Mars could be 1 to 3 months (less than half of what it is today). Once we figure out fusion, asteroid mining, space elevators, laser launch systems and other crazy ideas can all become reality. I couldn't be more excited!
To progress as species we need to conquer the power of nature and bend its will. I hope I live to see us conquer the power of the Sun.
So, where are we now?
Every article on Fusion will mention the same tired joke about the industry. I won’t bother repeating it here, because I believe it makes Fusion sound like an unsolvable problem. I beg to differ.
There is a big misunderstanding in the general public that since Fusion has been in development for ~70 years and we have no working reactors yet, it’s never going to happen. However, the rate at which scientists have been improving and increasing the duration of the reaction and power output exceeds the rate defined by Moore’s law in computer processor design. With several high-profile investments being made around the world and a staggering rate of innovation, Fusion deserves much more excitement and love than it’s getting right now.
We’ll probably live to see a functioning and energy-positive reactor within our lifetime and reap all the benefits it will create for humanity. Science is spectacular.
If you’re interested to learn more about the most exciting developments in the space, here is a short reading list I highly recommend to start with:
ITER (Biggest fusion project in the world): https://www.scientificamerican.com/article/worlds-largest-nuclear-fusion-experiment-clears-milestone/
More startups: https://www.bloomberg.com/news/features/2019-09-28/startups-take-aim-at-nuclear-fusion-energy-s-biggest-challenge
Thank you for sticking with me till the end! If you are interested in crazy tech, investing opportunities or just want to reach out, please do so here: