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Comment by iamcurious | Hacker News Reader

I find it strange there is no mention about batteries. From what I understand (and it isn't much, I'm way out of my field) getting energy is easy, saving it is hard.

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You can either collect and store energy where it's abundant but intermittent (solar, wind), or generate it reasonably close to the consumers.

The problem is that the sources like solar have both power density and availability problems in higher latitudes, and power density required to e.g. power a major factory may be a problem even in a sunny place.

I'm also not sure about price per kW of installed generating power; it looks like solar power is still way behind atomic power in this regard.

In general, everyone would love breakthroughs both in electricity generation, transmission, and accumulation. Looking at the amounts of coal still mined for burning, generation should not be overlooked.

Fusion and Fission systems tend to run 24/7, unlike Wind and Solar. There is far less need to store energy when using the former types of generation.

Fission: Nuclear power stations have relatively low capacity factors (a measurement of how much of time they're actually connected to the grid and producing power). This is typically 70% over the last few decades for Western countries (i.e. a third of the time, a nuclear power station is not producing anything). As well as unintended maintenance shut down periods, most reactor designs require a multi-month shut down to refuel. In recent years some countries have managed closer to 90%.

Fusion: By '24/7' you mean the 0.5 s sustained burn at JET in the 90s. Humanity has not yet managed to sustain fusion for a full second on the Earth, let alone get any useful power out of it. ITER (the next generation Tokamak test reactor) isn't built yet. The intent is for it to achieve 1000 s of fusion burn time. Its over budget and behind time, and they've just had a management reshuffle to try and deal with this.

* Edited & extended to try and incorporate nbouscal's feedback from below

Do you mean to include the entire U.S. as one of those states? Wikipedia lists nuclear's capacity factor as 90.3% in the U.S. in 2009, and 88.7% averaged over 2006-2012, according to the DOE: https://en.wikipedia.org/wiki/Capacity_factor#United_States
The Helion design which Ycombinator funds is pulsed, so sustained burn time isn't applicable. It's also much smaller and cheaper than mainstream tokamaks.

I think you would like to know that your comment is completely impenetrable to an average intelligent layperson. All the words are reasonably understandable, but I have no idea how they translate into a response to the parent comment. My guess is that you're falling prey to the illusion of transparency [1], though I suppose it's possible that you were only intending your comment to be meaningful to people familiar with the industry jargon.
[1]: https://en.wikipedia.org/wiki/Illusion_of_transparency
Edit: +1, much clearer what you mean now.

For over ten years the US nuclear fleet has maintained an average capacity factor of about 90%, and that is nearly 1/4 of the world's nuclear plants - http://www.nei.org/Knowledge-Center/Nuclear-Statistics/US-Nu.... It's not "some countries" it's most plants at around 90%.

If you can generate on demand then you don't need batteries.

Batteries are great when you need a relatively compact and lightweight source without moving parts and noise. That is, cars, helicopter drones, phones, etc. Batteries still lack the high energy density of fuels like kerosene; you cannot fly a jet plane or rocket on batteries.
Electric power can probably be used to synthesize traditional fuels from carbon dioxide and water, to stay carbon-neutral. Plants can do that but in a quite inefficient manner. A (bio)chemistry breakthrough is badly wanted on this front.

Indeed. The essay mentions "predictability" as a problem with solar, but that becomes moot with good enough storage & transmission.

Precisely! The issue is storage. There are many ways to create energy: solar, wind, water, nuclear (thorium!)...but storage is still unsolved. And Lithium is NOT the answer, not at the scale we need.

The storage problem is almost solved. Batteries/Supercaps with double the capacity, charge rate and lifespan of current Lithium-ions should be on the market soon.

That doesn't even close to solve the problem!
Lithium-ion batteries are still at least $100/kWh (probably more like $300/kWh) and assuming a useful life of 1000 charge/discharge cycles, you're talking between $0.10 and $0.30/kWh just for the STORAGE! That doesn't even take into account the cost of generating the energy to begin with, nor the losses that come with charging and discharging the battery, nor the capital cost on the inverter that absolutely isn't free and definitely doesn't last forever.
Until storage can be had for a few cents per kWh storage is an unsolved problem.
I suspect that it will continue to be an unsolved problem for quite some time. Not because it's impossibly hard, but because getting oil or gas or coal out of the ground is so easy and has such large energy gain (output energy / input energy) that you have to be very clever to beat it.

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