Cover by Alisa Zhang

Sunpower

By Parker Miller

If you’re a Spiderman fan, then you’ll no doubt remember Dr. Octopus. In the second installment of the original trilogy with actor Tobey Maguire, Professor Octavius1 was attempting to harness the energy of the sun, something he calls fusion power. Although the film framed this ambition as hubris, a dream destined to result in failure, Otto’s project bears some resemblance to the very real and exciting realm of fusion research. If you’re not familiar with the concept, there are two kinds of nuclear energy: fission and fusion. The nuclear reactors that are on the power grid today are powered by fission, a process by which atoms in a radioactive core —most commonly used elements are plutonium and uranium— are induced to split, releasing immense amounts of energy. The direct opposite is fusion, where lighter atoms such as hydrogen collide, overcome the electromagnetic force (the reason for the repulsive and attractive behavior of charged particles) and form a new, heavier atom. Fusion and fission reactions release comparable amounts of energy with one main difference, the waste in fusion reactions is radioactive for far shorter periods2 of time and is produced in much lower quantities3. The significance of this difference is that clean energy is integral to our mitigation of climate change, and with negligible byproducts, fusion energy enters the field of clean energy possibilities. With once in a life-time storms such as Hurricanes Irma and Harvey within two years of each other; with raging forest fires burning down millions of hectares of land in California and Australia; with the inevitability of rising sea levels as the Earth warms; either we change our way of life, or we change how we power it. Immediate solutions are, of course, necessary if we are to tackle climate change successfully, but fusion energy has the long-term potential to revolutionize the power grid far into the future. 

Before getting to the details of fusion and its potential as a clean energy source, I’d like to offer to you: the stakes of the climate crisis. You may have heard that we absolutely must keep the total warming of the global climate below 1.5°C or 2.7°F to avoid a runaway warming effect. The bad news is that you heard correctly: the runaway effect initiates when the planet’s atmosphere contains enough greenhouse gasses to prevent thermal radiation from exiting, forever halting its natural cooling processes.4 Worse yet, no form of energy besides nuclear fission is currently capable of completely replacing fossil fuel power plants.5 Many people oppose fission however, citing disasters such as Fukushima or Chernobyl. The question thus remains, how do we reach net zero emission of greenhouse gases? Renewable energies such as solar and wind are sadly too underdeveloped as yet to power the world’s growing energy grid6, a point which raises another: developing nations are constantly building modern infrastructure, adding to the already astronomical tally of global emissions. As its completely unreasonable to keep these countries from modernizing their infrastructure, we will require more energy, further delaying the time when renewables will be able to foot the energy bill. Studies suggest that on the current course, merely 50 years from today, one to three billion people will find themselves displaced by the effects of runaway climate change.7 Meaning that approximately speaking, everyone under the age of 30 will have to deal with the consequences. If I sound like I’m ringing an alarm… good. If it takes a climate alarmist to get people to pay attention, then I’ll gladly take up the mantle. Regardless of how much airtime climate change and its impacts find on the news, nothing changes. Mainly due to the fact that those who the status quo benefits are hesitant to change it, even when it means turning off the burner of the stove they're sitting on. 

Now that I’ve laid clear the risks associated with failing to address climate change, let’s get back to Dr. Octopus and his plans for fusion energy, and why fusion energy would serve as a clean, safe, and efficient alternative to fossil fuels. As I explained, fusion is the process by which atoms of lighter elements collide to combine into heavier elements. These reactions are what powers the sun and by extension, everything on Earth. You may have heard the sun being called a ball of plasma. Plasma is the fourth state of matter and is more simply understood as a cloud of electrically charged gas. In a plasma, the velocities of the atoms within are of magnitudes so great that when two ions collide, their nuclei are close enough in proximity such that the aptly named strong force overpowers the electromagnetic force and a new nucleus is born.8 In fusing together, the colliding atoms have an extremely small percentage of its mass transmuted into energy determined by Einstein’s famous equation, E=mc2. It explains that the amount of energy is equal to the mass lost in the collision multiplied by the speed of light to the second power. After running the numbers, this comes to less than 1x10-11J/fusion.9 This means that there’s just enough energy in a single fusion reaction to power a microwave for about 1x10-14 seconds! This might not sound like a lot, but rest assured; in plasma, there is… more than one fusion reaction taking place. And while Dr. Octopus sought to create a literal fun-sized star on Long Island, the real-life fusion energy looks very different. 

Once the process of fusion was understood by scientists to be the source of the sun’s seemingly limitless energy, the dream of many physicists became to find a way to harness fusion on Earth. We don't have the benefit of being as massive as the sun (if you could consider that a benefit), so we have to work a lot harder to get a stable plasma capable of inducing fusion reactions. By increasing the temperature of our plasma to far beyond the temperature of the sun, we increase the kinetic energy of the particles therein and the likelihood of fusion reactions. The reason for the increase in probability is that the rate of collisions increases. Not every collision results in a fusion of two atoms, but with more collisions, we will inevitably have more fusion. Naturally, to create these temperatures, a huge amount of energy must be expended. The fusion energy gain factor, Q, is a measure which represents the ratio of how much energy was used to the amount of energy gained in fusion. There are many global projects ongoing in order to increase the experimental gain factor. In the South of France for example, the International Thermonuclear Experimental Reactor (ITER), poised to finish construction by 2025 according to the most recent estimates, uses magnets to prevent the superheated plasma from coming into contact with and melting its container. ITER’s development team seeks to achieve a Q-factor of 10, meaning 10 units of energy output for every 1 unit of energy input. This number comes with something of an asterisk; a Q-factor of 10 is still not sufficient for the energy grid, since much of the energy produced is cycled back into the reactor. Nuclear physicist, Dr. Mark Henderson, stated that a Q-factor of 40 would prove fusion viable for energy production on a commercial scale.10 Since ITER only aims to set a gain factor of 10, fusion energy obviously remains a distant objective. Thankfully, there is a lot of financial support for ITER from across the globe. ITER is the most expensive science project ever at a whopping estimated cost of 18-22 billion USD, far more expensive than the Large Hadron Collider, but it was never marketed as a commercial reactor.11 There exists an international initiative that funds ITER formed by the following countries: the USA, China, Japan, the EU, Russia, South Korea, and India. ITER represents the ambition of the global community for a massive step forward in achieving viable fusion energy, but also an international cooperative aimed at finding solutions to climate change. It is through these enormous acts of international collaboration that we will be able to solve the climate crisis.  

The success of fusion as a commercially viable fuel source would be a huge victory in the fight against climate change. By replacing all currently functioning fossil fuel plants with a clean, highly efficient, and nontoxic power station, we could eliminate all greenhouse gas emissions from fossil fuels which currently produce more than 35 billion metric tons of carbon dioxide each year. Though fusion remains a far-off reality, the possibility for it to revitalize our energy grid is unignorable. Obviously, the need for immediate solutions to the climate crisis are necessary, but with the long-term plan to supplement our energy needs with fusion reactors, the future looks brighter than the sun.