The Future of Fusion Energy

May 12, 2019

The Future of Fusion Energy

The Future of Fusion Energy by Jason Parisi (YC ’16), a PhD student at Oxford, and Justin Ball, a researcher at the Swiss Federal Institute of Technology, attempts to shift the culture of popular science surrounding fusion energy. For decades, the literature has focused on the history and politics of fusion rather than contemporary research. As researchers in the field, Ball and Parisi set out to write a book that would empower the reader to understand the science and technology behind fusion.

The book’s cover features a donut representing the tokamak reactor—the focus of the authors’ work. Em­ploying magnetic fields that prevent charged particles from escaping the container, the tokamak reactor creates a magnetic “bottle” in which an electrical current circulates through plasma inside the reactor. The easiest fusion reaction to achieve using a tokamak reactor is fusion between deuterium and tritium, two isotopes of hydrogen. The isotopes are heated to the temperature of the sun and react to produce a helium nucleus and a neutron. The neutron carries most of the energy obtained from the reaction and deposits its energy in the form of heat on a blanket of lithium metal outside the reactor.

“A kilogram of fusion fuel powers your complete lifelong energy needs and those of your hundred closest friends,” Ball said. “[Fusion] could replace all your coal and your gas, and maybe some of your old fission plants,” Parisi added. He suggests that fusion could reduce environmental destruction from energy generation: the inputs for fusion are deuterium and lithium, which are common on Earth, and fusion is so energy dense that obtaining the necessary lithium would have minimal environmental impact.

However, there are obstacles to designing commercially viable fusion plants. “Having materials that can with­stand the heat flux carried by the plasma to the wall of the reactor is a challenge,” Parisi said. Another challenge is located in the plasma of tokamak reactors: turbulence causes heat to leak out of the reactor, potentially resulting in the energy spent heating the fuel exceeding the energy generated. Both Ball and Parisi’s research centers on turbu­lence in fusion reactors and trying to understand what happens at the edge of the reactors—where energy leaks out.

In spite of the hurdles, fusion reactors remain the holy grail of energy sources. Ball and Parisi believe fusion could potentially be used to fuel spacecrafts, redefining the boundaries of space exploration.

The Future of Fusion Energy stands out with its success in putting fusion within the grasp of readers. The novel begins with a brief history of energy sources and defines terms as simple as isotopes before covering the workings of fusion. Moments for pondering are interspersed throughout the novel before explanations of technical con­cepts. This writing style is indicative of what Parisi and Ball accomplished with their book—making a complex technology understandable to the general public and ensuring its importance is not lost on readers.