Fusion Milestone Reached. Many Miles Left To Go.

It was in the news last week that scientists at Lawrence Livermore National Laboratory (LLNL) in Livermore, California, on the edge of the SF Bay Area, achieved a breakthrough in nuclear fusion. In the multi-billion dollar National Ignition Facility (NIF) they created a controlled nuclear fusion reaction that generated more power than it consumed. Lasers pumped 2.05 megajoules of energy into a fuel pellet; the reaction generated 3.15 megajoules of output.

Okay, to call this a breakthrough is a bit optimistic. It's certainly an important milestone, though. It's the first time a controlled fusion reaction has generated more power output than input required.

Scientists talk about this as a ratio, Q, of output to input. In this experiment Q = 1.5 (approximately). While this being the first time reaching Q > 1 is huge, scientists figure we'll need to get to Q = 10 to make power generation cost effective. Though even the current Q = 1.5 is misleading. That's counting the amount of power the lasers fired into the fuel. Powering the lasers actually cost 100x as much energy— the amount measured by "the meter on the wall", if you will.

Fusion power generation also requires a sustained reaction with Q much greater than 1. NIF's December 5 reaction lasted only a fraction of a second because of limits managing the incredible heat generated. And even the brief experiments up to this point have stressed the machinery at the multi-billion dollar NIF enough that it will need a costly rebuild.

So, this month's experiment isn't really a breakthrough, though it is an important milestone. Just keep in mind that there are many miles left to go.

Update: Okay, so how long until we have Mr. Fusion powering our cars?

From Kitty Hawk to Mr. Fusion?

I blogged this morning about the breakthrough milestone in nuclear fusion achieved at Lawrence Livermore National Laboratory earlier this month. As I explained it's not really a breakthrough (IMO) because what was achieved was so... preliminary. An operational, scalable solution is still countless steps away.

Some arguing to call this a breakthrough compare it to the Wright brothers' first powered flight at Kitty Hawk in 1903. Indeed, the new field of aviation rapidly developed into a commercial and military success not many years after that. Just under 66 years later we landed a man on the moon! Surely it can't be that long until Mr. Fusion from Back to the Future becomes a reality....



Alas, solving for nuclear fusion is way more complex than designing aircraft.

Back to the Future was set in 1985. At the end of the film a future Doc Brown arrives from 2015 with a fusion reactor— cheekily named Mr. Fusion— powering his time machine Delorean on banana peels on stale beer. 2015 vs. 1985.... Thirty years later.

That's a curious coincidence because scientists and science writers have been saying for quite a while now, "Fusion power is 30 years away." Note, of course, that it's perpetually been 30 years away. "30 Years" is science shorthand for, "We're not saying it'll never happen, but there's no way we can draw a map right now for how to get there from here."

And this Kitty Hawk moment? Well, maybe it moves the needle down to just 29 years.