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Comment by nxzero | Hacker News Reader

Has anyone since reasonable explanation of what the future would look like with fusion?

To me, there will never be enough energy, this effort is about control, not power; even if there was (relatively speaking) an unlimited source of energy, the bounds of it's use would quickly be found, and as such, would not be "universally" available.

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I think the first world would look much like it does now, except that fusion would replace most current nuclear, coal, and oil-fired plants - the technologies that supply base load. Natural gas plants will continue in service as fast response peaking plants.

Renewable energy sources will continue to replace older generation technologies so long as they continue to get cheaper and grid modernization keeps pace with the special requirements of renewables wrt variability.

All that depends on whatever fusion tech proves to be both technically feasible and cost competitive. If that doesn't happen, or is really delayed, then grid storage technology may win out as a cost-effective energy "source".

If storage becomes cheap and effective I'd expect to see renewables + storage expand to serve base load. Also, we'd see faster electrification of areas that currently can't afford classic distribution grids. This might accelerate significant changes in the developing world.

But whatever the generation technology, energy won't be "unlimited". There will always be cost limits.

There are also fundamental thermodynamic limits that you hit at some point. All production and usage of electricity produces waste heat, it's unavoidable (see Carnot). Even neglecting global warming, you can't keep 20th century energy growth going for much more than another century or two before waste heat alone causes catastrophic climate change.

you can't keep 20th century energy growth going for much more than another century or two before waste heat alone causes catastrophic climate change.

That seems unlikely to me, but I'd be happy to be proven wrong.

I would imagine that all of the waste heat produced through the world's economy is several orders of magnitude lower than the sun. Like less than 0.0001%.

True, and waste heat is a far smaller contribution to warming than greenhouse gases.

But exponential growth gets impressive after a while. At 2.3% growth per year, we boil the oceans in about 400 years: http://physics.ucsd.edu/do-the-math/2011/07/galactic-scale-e...

Whether this is physically or economically realistic is another matter. I tend to think that long before waste heat is an actual problem, we'll either transition to a stable state or move the growth off planet. (Conveniently, fusion is also great for rockets.)

Well, that assumes we don't move manufacturing processes off planet. Which is more realistic when nigh-unlimited energy (fusion) is available. With that, you can do cool things like launch loops or even a space fountain.

Hence my last paragraph. But alternative launch systems is a good point.

Waste heat could possibly replace natural gas for heating. Eventually that won't be enough, but I'm sure by the time it becomes a problem we'll figure something out.

My first thought was that an electricity cost at maybe 20% of what it is now would be result in a good economic uplift but not a seismic change.

But the interesting cases are those where much cheaper electricity unlocks new opportunities. Imagine the coast of sub-Saharan Africa transformed by the agriculture enabled by cheap desalinated water.

Is it really just a 5x reduction in power cost that would allow "cheap" desalination? Would it require a 50x reduction in cost? I wonder if cheap desalination and cheap desalination are on the same order of magnitude. Do you know the current cost of desalination? Is there any sort of accurate estimate of how cheap power would be? (I guess not since everything is a prototype and nothing has been able to produce excess power from fuel).

Electricity already makes up around half or less of the cost of desalination. Even free electricity would at best halve the cost.

Assuming current designs. There may be less energy efficient designs that are, ignoring the cost of energy, cheaper to builder and operate.

While I think that is true in general, and we will eventually saturate whatever fusion may provide - it will take a good while to do that. And in the mean time, we'll have a near perfect source of energy, that's cheap, plentiful and clean.

Fusion is truly a pretty revolutionary thing if we can make it work.

Why is it cheaper than now? I mean coal is really cheap. You still have to pay people to operate these reactors. It is not like we have a scarcity of coal. I get clean I do not get cheap. Yes the fuel will be water but these things must have large overhead to maintain and run and build.

For things like coal and oil the cost is in acquisition, transportation, and storage of the fuel and the infrastructure that goes with that.

You can't just go out and find coal lying around. You need to hallow out or level an entire mountain to get it. That requires a lot of people and equipment. And you need to transport large quantities of it around to where it's needed which requires special infrastructure dedicated to that task. The same goes for oil/natural gas.

Capitalism is always about control.

At the center of our society/culture is the human being's desire to dominate others. We use capitalism/money as a means to achieve that. Money/power always has a systemic property to create monopolies and reinforce them.

That being said, technological advance usually benefits more than just the owners of capital. But the balance usually is tipped in their favor.

In short: There's enough food for everybody on this planet, but we currently prefer to have more of it for ourselves and let others starve.

If we don't like this system, then we need to move away from capitalism (as we know it) and put different values than domination/power/money at the center of our culture.

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