Frequently asked questions.

A power-solutions man pointing technology at TAE Technologies

What is fusion energy?

Fusion is nature’s preferred source of energy. It’s the same process that powers the sun and stars, and it’s what makes life viable on Earth. It can be explained by Einstein’s Special Theory of Relativity, better known as E=mc2. Energy equals mass multiplied by the speed of light, squared. Fusing two light elements together produces a new element (or elements) whose aggregate mass is slightly less than the combined mass of the original two elements. This rather tiny difference in mass, multiplied by the incredibly large number of the speed of light (nearly 300 million meters per second), squared, drives a tremendous release of energy.

How do you produce electricity from fusion?

Our sun presently fuses predominantly hydrogen atoms to give off energetic light. We are trying to recreate this same process, adapted for terrestrial conditions. In TAE’s future fusion power plant, we will fuse hydrogen and boron to produce an even more energetic light than the sun. Just as you feel warmth when sunlight hits your skin, in a power plant, the containment vessel wall will heat up from energetic light emanating from the plasma. The wall will be cooled through a network of pipes, which have working fluid streaming through them to pick up the heat and transport it to a steam generator. The steam spins a turbine that then drives an electric generator, similar to what happens in operating power plants today. TAE’s unique fusion core supplies a superior and environmentally benign heat source for future power plants.

Why don’t we have fusion power plants yet? What is the central challenge?

Generating power from a terrestrial fusion power plant depends on two conditions: maintaining plasma at sufficiently high temperatures and for a long enough amount of time to sustain the fusion reaction. TAE calls this the Hot Enough Long Enough (HE/LE) requirement.

For reactor performance levels, Hot Enough means reaching at least 100 million degrees Celsius, a temperature that is readily achievable today. However, sustaining that hot environment is extremely challenging because plasma is a delicate substance that must be protected from conditions that would otherwise decay it or cool it down. Terrestrially achievable plasma contains very few particles, especially compared to the particle density in the areas surrounding the plasma, such as the metallic walls of Norman’s containment vessel or even the air we breathe. Consequently, those areas can store much greater amounts of heat than what is contained in the plasma. These factors are responsible for the rapid loss of energy out of the plasma and into the environment. Fusion’s goal is to minimize this loss so plasma can be maintained with less energy than the fusion reaction generates. By doing so, net energy can then be released to the electric grid.

Over the past 50 years, the different fusion efforts around the world have worked to overcome this fundamental challenge in different ways. In December 2022, the Lawrence Livermore National Laboratory’s National Ignition Facility (NIF) recorded net energy gain for the first time in the history of fusion research, and repeated their findings again in August 2023. Read TAE’s statement on how this landmark achievement marks the dawn of the fusion age. Learn more about bringing fusion power to the grid on TAE’s podcast Good Clean Energy.

What is plasma?

You are probably familiar with the different states of matter: solids, liquids, and gases. Plasma is considered the fourth state of matter. If you heat up an ice cube, it will transform from a solid (ice) to liquid (water) to gas (steam). If you superheat the gas further, negatively charged electrons will break free from the core of the formerly electrically neutral parent atoms, rendering them positively charged. These are called ions. This combination of highly energized positively charged ions and the negatively charged electrons forms a soup called plasma – imagine lightning.

What is TAE Technologies’ unique approach to confining plasma?

Achieving fusion is essentially the task of creating and containing lightning in a laboratory. Plasma is a fickle, oozy substance. The challenge of containing it is akin to holding Jell-O together using rubber bands. You may attempt this by using an increasing number of rubber bands in order to create a suitable physical barrier. Or you may seek ways to alter the texture of plasma to make it more cohesive, similar to adding more gelatin to runny Jell-O.

TAE Technologies’ unique approach to fusion combines the deepest insights from the two distinct fields of accelerator physics and plasma physics to tame plasma and solve the challenge of confinement. We use accelerators to inject beams of high energy particles into the plasma, which act as a “thickening” agent that makes it more manageable. As a result, this means fewer energy losses and more energy to release to the grid.

How does nuclear fusion differ from nuclear fission? Can a fusion plant experience a meltdown?

The fusion process is the exact opposite of fission. Although both are carbon-free, occur at the nuclear level and release energy as a byproduct, fusion achieves this by combining light elements such as hydrogen, deuterium, and boron, while fission splits up heavy atoms such as uranium and plutonium. Fusion doesn’t produce long-lived radioactive waste, whereas the radioactive waste stream from fission can last for 10,000 years or more.

A fusion plant cannot experience a meltdown. Fission is propagated by a chain reaction. Once the reaction starts, it’s hard to stop. In contrast, fusion is a driven process, meaning all steps are deliberately initiated and actively maintained. Once the external drivers stop, the fusion process stops – faster than any kill switch or emergency power-off system could shut down a plant. Fusion possesses nature’s ultimate safety valve: there is simply no way for a meltdown to occur. In this way, fusion is an inherently safe proposition.

What is the difference between hot fusion and cold fusion?

The fundamental difference is in the parameter space of the fuel. In cold fusion, research is being pursued at room temperature, within tabletop experiments. The fuel used in cold fusion is approximately the density of liquids or solids. In contrast, hot fusion occurs in large, sophisticated machinery capable of achieving temperatures in the millions or billions degrees Celsius, and produces very low-density plasmas (100,000x less dense than air at sea level). Almost all of the world’s fusion research is focused on hot fusion.

What is a fuel cycle and how does it affect fusion?

There are several known fuel cycles for terrestrial fusion, i.e. different elements that can be fused to produce fusion reactions and, ultimately, electricity. The most common fuel cycle is deuterium- tritium, or D-T, because of its comparatively low temperature threshold for achieving the Hot Enough requirement for fusion (100-150 million degrees Celsius). Other fuel cycles include deuterium-helium-3 or D-He-3 (many hundreds of millions degrees Celsius) and hydrogen-boron or p-B11 (in the billion-degree Celsius range).

How does p-B11 compare to other terrestrially achievable fuel cycles?

The lowest temperature for a fusion reaction to occur; fastest reacting fuel cycle, with very large energy output per reaction.
Challenges: Tritium is a radioactive element – it does not occur in nature and must be bred; its associated neutrons will accelerate aging in power plant materials.

Substantially less radioactivity and production of tritium than with D-T fusion, leading to longer power plant life; most energy output per reaction, largely in the form of energetic protons, which makes direct energy conversion possible.
Challenges: Residual radioactivity; reacts slower than the D-T fuel cycle; no terrestrial He-3 resources – must be mined on the lunar surface.

Aneutronic (primary reaction yields no neutrons); cleanest, safest, highly abundant, and environmentally friendly fusion pathway; enables scalable, cost-competitive electricity.
Challenges: Requires superior confinement and operational conditions to reach the considerably higher temperatures needed; reacts more slowly than other fuel cycles; less energy output per reaction.

It's often repeated that “fusion is always 15 (or 30 or 50) years away.” Is that true?

No. There is a new confluence of factors that makes the entire pursuit of fusion different than it was even 10 years ago. In the early years, we didn’t understand the true magnitude of the challenge, and more importantly, we didn’t have the proper tools to address it. Exponential progress in the science behind fusion, coupled with the emergence of critical support technologies, has now created the proper tool chest to bring us to the cusp of fusion. These tools include expanded scientific knowledge about plasma behavior, artificial intelligence, machine learning, faster electronics, magnets, improved diagnostics, shorter latency feedback loops, materials science, vacuum technology, power electronics – the list goes on. Whether discovered by TAE Technologies, our fusion colleagues, or a serendipitous development in an unrelated field, these advances are now cumulatively and critically enabling. With over $5B invested in 25 private fusion companies, as well as massive international efforts underway, there is no doubt that commercial power generation based on fusion is fast approaching.

Why has there been a recent proliferation of private fusion companies?

With more awareness about the need for an environmentally benign, high power density energy solution, and with thought leaders such as the late Stephen Hawking strongly advocating for fusion as a permanent clean energy solution for the planet, it makes sense that more companies are joining the field. In recent years, new technologies have come into existence that provide foundational capabilities to accelerate development and fundamentally enable fusion power.

Advances in machine learning, artificial intelligence, computer-controlled power management and superconducting materials – to name just a few – all make the achievement of fusion inevitable. That potential leads to more investor interest and financing, which, by extension, leads to the awakening you’re seeing now.

What is the advantage of private investment in fusion?

The existence of parallel programs, both public and private, enables holistic exploration of the fusion opportunity, and all efforts approach their research in different ways. For TAE, private funding provides a singular forcing function that ensures efficient use of capital, disciplined project management, and focus on the mission-critical elements and goals. TAE Technologies was founded with the express purpose of developing and licensing commercially viable fusion energy technologies and has charted its course to this outcome ever since. For the past 25 years, the company has operated on a “money by milestone” model, where each round of funding is only earned based on delivering on milestones that were promised to investors.

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