What the nuclear fusion breakthrough means for our future

Nuclear fusion can be used as a source of energy for electricity. For the first time in fusion experimentation, 192 lasers were used.

The Secretary of Energy called it a "fusion breakthrough" at the press conference.

History will record this as a breakthrough because it doesn't mean you can flip on the lights in your house and use fusion energy for a long time. The Lawrence Livermore team aimed lasers at hydrogen atoms, and for a split second the atoms became a fusion reaction. The laser energy caused a reaction that heated the atoms to millions of degrees Celsius. The fusion gave off 3.15 megajoules of energy.

The fusion reaction produced more fusion energy than the lasers did.

You can think of previous fusion experiments as matches hitting against the strip on the matchbox and causing sparks. The match head had never produced a flame. The paper stick is too short-lived and inefficient to be used to light other things.

Arthur Eddington's "The Internal Constitution of the Stars" was published in 1926 and scientists have been working towards a demonstration like this ever since. Researchers have been working on fusion for a long time. It is possible to make a fusion reactor in your garage.

The challenge of fusing those atoms efficiently enough to call them an energy source is still the challenge moving forward.

At some point in the future, fusion may be the king of clean energy. fusion's development timetable is not a realistic solution to the climate crisis. The fusion reaction produced a net gain in energy within the experiment, but what it didn't do was produce enough energy to power the facility that performed the experiment with enough left over to do it again.

Blue lasers compressing a fuel capsule at the National Ignition Facility. Credit: LLNL / National Ignition Facility

This isn't a secret. The laser requires about 300 megajoules of energy from the wall to drive two megajoules of laser energy. There is a pathway to a target that can produce enough yield, but we are far away from that right now.

It is disappointing that the efficiency of this system is less than one percent, since it is being hailed as the biggest fusion breakthrough of all time. There are other ways to generate grid energy that don't use 192 lasers. One method is to use a magnetic field to hold the fuel in place, instead of using a laser to destroy it. Back in the early 1990s, similar experiments produced similar breakthrough.

By coming in the same year as a doubling of private sector funding for nuclear fusion as an energy source, this breakthrough is well- timed to redefine fusion in the popular imagination. The war in Ukranian brought about discussions about energy security. As Russian control over oil and gas supplies endangers Europe's ability to provide enough energy to heat itself this winter, the promise of a plentiful and relatively safe form of energy has never been more welcomed.

Being 30 years away from fusion is a cliché. We need a new joke because the time line is out of date. Don't sell your solar panels and keep building powerful wind turbine in the meantime.