Thread by @JavierBlas

I have written only one story about fusion energy. For my university's newspaper 25 years ago. Thankfully, it isn't online.

Since then, I'm skeptical of surprisingly well-timed announcements by budget-starved laboratories about breakthroughs for technologies decades away |🧵1/10

But first, the FT story (confirmed now by others, including Bloomberg) about the US Lawrence Livermore National Laboratory near San Francisco set to announce that a fusion experiment released more energy than the lasers used in the experiment emitted 2/10 ft.com/content/4b6f0f…

There's a caveat to the story. The same laboratory announced a slightly different breakthrough nearly a decade ago (by Nature), announcing it achieved a net energy output vs the energy **absorbed** by the fuel. The new breakthrough is superior | 3/10 nature.com/articles/natur…

If confirmed, the breakthrough is quite important, putting the world into the realms of "fusion ignition", and perhaps in the future into a sustained and controlled fusion reaction. Sustained is a key word there. The current experiment lasted a fraction of a second | 4/10

There a few extra caveats. What net energy means? The lasers used by the Lawrence Livermore laboratory are extremely inefficient, so although the experiment produced net energy compared to what the laser delivered, the lasers consumed a LOT more before to charge | 5/10

The experiment released 2.5 megajoules vs 2.1 MJ of laser energy. But due to inefficiencies, the lasers consume ~330 MJ to charge, with the energy stored in 3,840 high-voltage capacitors for 60 seconds before being released in a 400-microsecond burst lasers.llnl.gov/about/how-nif-… 6/10

Even by those caveats, the experiment is a massive scientific breakthrough -- but don't think you are about to enjoy free and clean energy tomorrow. Or next year. Or in 20 years or, perhaps, even 50 years. Commerciality is far, far away. If ever. Many obstacles remain 7/10

One example, the current lasers used in the experiment can fire, at best, only **once a day**. For commerciality, they will need to fire several times **per second**. That's a sign of the many and further breakthroughs they are needed to secure clean and free energy | 8/10

Should we spend some billions in fusion research when fision energy is readably? Yes, we should, but we should too keep building fision nuclear power plants. Science is about discovery: let scientists experiment -- and wait. Many scientific breakthroughs came as a surprise | 9/10

But from all what we know today, we still need to wait more time for a fusion energy-version of the famous line:

"The Italian navigator has just landed in the New World"

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