When Can We Expect Nuclear Fusion?

Nuclear fusion is the hottest new energy source in science—quite literally.

Milestone breakthroughs have been made in the field of fusion power, taking us even closer than before to the possibility of generating electricity using only hydrogen as fuel. While the technology is still many years away from being widely used, the hope is that some nuclear fusion reactors will be fully operational by 2027.

Nuclear fusion is the process that powers our sun and other stars across the universe, and occurs when two atoms—usually hydrogen—collide and fuse, forming another element. In the core of our sun, hydrogen ions require temperatures of at least 27 million degrees Fahrenheit to reach high enough energy levels to fuse to form helium.

This is because huge amounts of energy are needed to ensure that rather than the positively charged protons in their nucleus repelling each other like the end of a magnet, they come together and combine.

This process proceeds to release immense amounts of energy, which we hope to one day fully harness and use to generate electricity.

How Feasible Is Nuclear Fusion?

While we are still a long way from using fusion to power our cities, recent years have seen big breakthroughs in achieving and maintaining fusion.

Late last year, scientists at Lawrence Livermore National Laboratory's National Ignition Facility (NIF) in California announced that they had achieved a net energy gain from nuclear fusion for the first time. This essentially means that more energy was generated from fusion than was originally put into the reaction.

However, no commercial fusion reactors have yet been created.

"This is because the energy that has been produced in these experiments is significantly smaller than the energy required to fire the lasers, for example," Gianluca Gregori, a professor of physics at the University of Oxford, told Newsweek. "Last month, NIF has demonstrated that fusion reactions can produce more energy than the laser energy used to spark the process. This is very important since it proves that the idea is sound, but, of course, to have positive energy gain to the grid (that is, accounting for the electricity needed to run the lasers) you need a much more efficient process."

What Is the Current Status of Creating Nuclear Energy Using Fusion?

Many countries have teams of scientists working towards perfecting fusion power.

"[There is] NIF in the U.S., [and] there is a similar laser operating in France. It is called Laser MegaJoule (LMJ)", Gregori said. "It is not yet at a stage to perform ignition experiments as those done on NIF, but it is getting there. Many other countries (U.K., EU as well as Japan, Russia and China) have smaller laser systems. I believe China may be in the process of building a large laser comparable to NIF and LMJ, but I am not sure on the status of that project."

France also hosts an international project called ITER, which involves a consortium of scientists from around the world.

"These advancements bring us one step closer in the quest for this new energy source," Friedrich Aumayr, director of the Institute of Applied Physics at Vienna University of Technology, told Newsweek. "There is also rapidly increasing commercial interest that fusion can make a contribution to the world's future low-carbon energy supply."

Why Isn't Nuclear Fusion a Practical Energy Source at This Time?

There are still many challenges to overcome before fusion can be properly used. For one, the incredibly hot hydrogen plasma inside the reactor needs to be efficiently contained using magnets.

"The main challenge for us at this stage is to keep pushing along the path of improving how we heat up, pressurize and contain the hot, dense plasmas that nurture the fusion reactions to happen," Nathan Garland, a lecturer in applied mathematics and physics at Australia's Griffith University, previously told Newsweek.

"As we build better magnets, bigger lasers, stronger materials to withstand the immense temperatures and energies required to contain these fusion plasmas—think trying to bottle the core of our sun—we'll get closer to our eventual goal of generating enough energy out of the fusion reactions that we can harness it into a source suitable for powering our electricity grid," he said.

One of the main limitations of research is the cost, too.

"Nowadays, the cost of building the facilities as well as the cost of running such facilities is exorbitant compared to the amount of energy it delivers," Gregori said. "This doesn't mean it will [not] be possible some time in the future. An example that a colleague made sometime ago is the following—think of the first planes made by the Wright brothers. They definitely were not the most economical way of transporting passengers—but they could demonstrate the principle of flying. Modern (commercial) aircrafts are very different from those ones, in the same way a future fusion plant will be different from the current NIF."

How Soon Will We Have Fusion Power?

"[The most advanced fusion reactor is] presently JET [in the U.K.]," Aumayr said. "But 80% of the next machine called ITER [has] already been completed, with operation to be expected to start around 2027.The international ITER fusion device is planned to be the first magnetic fusion device to demonstrate more fusion output than necessary to heat the fuel: 500 megawatts of heat out, at 50 megawatts of heat going in, maintained for 15 minutes or more."

"The most advanced experiments are close to the brink of producing net energy from fusion. For a power plant this is not yet enough, but needs to be increased," Aumayr said. "But we are constantly learning more and I am convinced that we will have plenty of fusion energy available in our grids in the second half of this century."

While the halcyon days of fusion being used as a near-infinite, non-polluting energy source are still far off, scientists around the globe are working tirelessly to turn this science-fiction technology into reality.

"As Niels Bohr, a Nobel Prize physics winner (and one of the fathers of quantum mechanics) once said 'Prediction is very difficult, especially when it is about the future'," Gregori said. "As private companies are getting more interested in fusion energy it is possible that progress will grow exponentially and a commercial fusion plant may become a reality earlier than expected."

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