"Practical" is in there.

A price competitive 10 MW generator probably meets that standard though (Islands, small towns, isolated mills, etc).

...very fast spaceships for the solar system, interstellar big ones probably. With continous thrust.

That would likely not demonstrate grid comparable cost though.

I didn’t mean to move the goalposts. I just want to exclude demonstration projects that might produce some net energy but not be serious commercial sources of electricity. But thanks for accepting anyway.

I've sent an message to the address listed in your profile, it's coming from a nonstandard domain though, so if you don't see it, it may be in spam. Also, I now realize that the longbet page is still under review, so you might not be able to see that either until the staff approve it.

I wonder how many of the bets on the longbets site stem from HN discussions. Probably not a significant number, but it would be deeply interesting to go back and read the discussions that spawned them.

Longbets should include a link to the thread in question in the bet.

Edit: Would be nice to have a link to refer back to the discussion that led to the bet. To my knowledge, most bets do not provide such a citation.

Is that a prescriptive or descriptive statement? I just looked at about 20 and didn't see anything immediately obvious, but that was with in page text search, and not actually paying attention enough to tell whether it's common or encouraged to include a link to online discussions in general (and I would happily search for a data set or scrape the data if I could expect to find it there).