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Comment by otherme123 | Hacker News Reader

I don't hate it, but am not fanboy either. Imagine you can have nuclear fission and uranium is already found in nature ready to go to the reactor. Even in that case, nuclear fission could not beat solar or eolic ROI.

Even if nuclear fussion had the advantage of free combustible, the costs of building and manteinance alone could make it not practical. As of today it's not enough to have positive net return, but to have a LCOE of maybe $60/MWh (and going down). Current estimates put fussion at $120/MWh.

If it can't keep up with solar and eolic rade of fallig prices, it might be only suitable to replace fission power (which is not falling), about 10% of the grid. And there have been literally billions spent in research.

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> Even in that case, nuclear fission could not beat solar or eolic ROI.

Neither solar or wind are free. There are costs associated e.g. with building, shipping, maintaining, decommissioning these things (and hopefully at some point recycling, but that’s not solved). Looking at the whole picture, these costs are not that different. These technologies are complementary, they have very different characteristics.

> Current estimates put fussion at $120/MWh.

Current estimates are completely unreliable, because no industrial-scale demonstrator was built. They are a useful tool for planning and modeling, but not solid enough to build an industrial strategy on them. (And it’s “fusion”)

I don't think current costs for fusion are useful for modeling, or really anything, because there's nothing there yet. We don't even have prototypes.

But if there is not a clear and speedy path to get fusion to $30/MWh it's not going to make it. Batteries, solar wind, and geothermal are all busy deploying and getting cheaper every month, year, and decade. The grid system possible with 2035's solar and battery tech is going to be completely unimaginable to today's grid ops.

Did anybody say they are free? But the costs of running solar or eolic are way lower than the costs of running fission, or the costs that likely would be running a fusion central. In case you don't know what ROI means, it is return on investment (i.e. building, shipping, mantaining decomission...).

As of today, we are closer to mass batteries as renewable companion than fusion, at least in terms of ROI. If both end up competing for lithium, it would go to batteries unless fusion becomes dirty cheap.

Current estimations are useful because they mark the starting point for fusion: they are at around 120. They need to reach 80 to replace fission. They need to reach 60 to replace batteries. Assuming batteries don't get better ROI.

Same numbers were useful 30 years ago for solar: it was fully functional, but not yet economically sound. It was not much than a toy and a promise (as it is fusion today). Only when prices made sense it turned to a serious energy source.

About lithium: DT fusion needs mostly Li-6. If it were separated, batteries would work just fine with Li-7.

I recall a story of some lab that was trying to make a lithium-based neutron detector. It wouldn't work, and when they investigated they discovered the lithium they had bought was almost pure Li-7. It was surplus sold back into the chemicals market from the US hydrogen bomb program (which needed Li-6).

> As of today it's not enough to have positive net return, but to have a LCOE of maybe $60/MWh

If you don't count externalities (see cost of firming intermitency [1]).

> (and going down).

Not the last two years according to LCOE+ 2024. the main culprit is inflation, but the curve was nearing flat anyway.

[1]: https://www.lazard.com/media/gjyffoqd/lazards-lcoeplus-june-...

When I go to https://model.energy/ and solve for the cost of energy from renewables + storage in the US, using 2030 cost assumptions, the cost is less than $0.05/kWh. This is providing synthetic 24/7/365 baseload power, so all intermittency has been taken care of.

Problem solved then?

We should give the folks at model.energy the next peace prize for their effort.

You don't have to go that far, but you could at least listen honestly to what that model, and what more complex models, are telling you.

You're answering to a post I made saying that prices that were quoted from the Lazard report don't reflect all that's writen in the report.

Your answer gives a model unrelated to the figures I was discussing, with extremely agressive prices [1] set as hypotheses and zero network costs factored in. Sure, I can accept it as a minimum limit for the cost of a system, but that's not a very useful information, and you're not quoting this price as a lower limit either.

I don't see an honesty issue here, just someone believing that spherical cows are going to produce milk tomorrow.

[1]: e.g. the Lazard report quotes utility PV at $29-92/MWh, while your tool quotes it at 21.7€/MWh.

Solar is cheap, but it's only a supplementary power source. If you add in energy costs it becomes much, much more expensive than fission.

The elephant in the room is natural gas which is the true competitor to fission and is still dirt cheap in the US.

No, with proper system design solar + wind + storage is cheaper than new construction nuclear.

There's a reason China is installing two orders of magnitude more solar than nuclear these days (nameplate capacity basis).

China is also the top consumer in the world of coal and they continue to break their record every year.

On the margin I don't argue that renewables are cheaper, but you still need a way to generate base load power on demand.

You can generate baseload power from non-baseload sources. Renewables + storage can do the whole job. There is no need for anything called a "baseload source". Indeed, that label indicates a deficiency, not a capability: it's a source that has to run (almost) all the time to make economic sense.

China needs every power generation it can build.

I've seen cost estimates around there for tokamaks. If Helion actually works, their estimate is more like $20/MWh, and it looks pretty plausible given their reactor design. They would have relatively low neutron radiation, direct electricity extraction without a turbine, factory-built reactors transportable by rail, and no particularly expensive components like superconductors or fancy lasers.

Some of the other designs also look relatively cheap. Tokamaks are just the one we understand the best, so we have the highest confidence that they'll work.

We have highest confidence that tokamaks will "work" in the sense of reaching a physics goal. We have very little confidence tokamaks will "work" in the sense of reaching an engineering/economic goal. Too often the former is confused with the latter in these discussions.

No argument there, I just didn't spell it out since we were already throwing around specific levelized costs anyway.

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