So just to fantasize for a bit,

Suppose fusion power becomes a thing, and after handwaiving some issues let's assume it can power everything indefinitely.

Does that make things like heating, cooling, travel, ocean desalination, bandwidth, AI, Bitcoin mining, permanently free?

Shouldn't all of humanity be homing in on that holy grail?

I read here and there that geothermal could be the next best thing. Maybe HN can say more on that.

(P.S. terrestrial fusion may also explain why nobody bothers to build Dyson spheres out there)

In short: yes. It can be done. Clean, almost limitless energy, funded in a way to provide effectively free electricity for ordinary people. Restrictions would have to be in place to prevent true excess, but regulations already handle such matters in other areas.

The ambient vibe of our time, and here on HN, is often really pessimistic. I don't believe such pessimism is realistic. Commercial grade fusion power will come, and we should push very hard to make it happen. It will change the equations at the core of the economy and open up whole new paths for technology -- far beyond the pure digital.

By the time we get fusion (say 5 years) the solar+battery solution will be so cheap that it will be preferable to grid electricity (free to produce, expensive to transmit).

No.

There is always some capital and operational costs. Plus transfer. Limit is cost of infra and operations. And the financing costs. So you can get to very cheap, but not free.

Then some very rich and powerful people become very unrich and unpowerful. And they could never let that happen willingly.