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Comment by lordfrito | Hacker News Reader

No one wants to acknowledge that the economics will likely never work out for the reasons you mentioned. Too much maintenance -- and very expensive maintenance at that. It's far cheaper cost per watt to build a traditional fission reactor and run/maintain that.

Another reason is that ̶t̶r̶a̶n̶s̶m̶i̶s̶s̶i̶o̶n̶ distribution costs are half of your energy bill... so even if you could theoretically get fusion energy generation for "free" (which is impossible) you've still only cut your power bill in half.

Edit: I meant to say distribution costs not transmission. Looking at last months bill I paid $66.60 to deliver $51.76 of energy (about 56% of my total bill was delivery). The raw distribution charge was $49.32 or 42% of the bill. I'm not alone in these numbers, but your mileage may vary.

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Transmission is a really interesting problem that creates all kinds of distortions.

Say a house uses 10,000kWh per year at $0.10/kWH so $1000/year electrcitiy bill. Now say you get a solar system that produces 5,000kWh per year, focused in the summer months (where your power bill tends to be higher anyway). You may even export some of that power back to the grid. Have you cut your power bill in half? No. It's probably down ~20-25%.

Why? Because regardless of how much power you use (within limits) you still need a connection to the power grid and that needs to be maintained. You'll often even see this on the electricity bill: fixed charges like "access charge" per month.

We benefit from being on a connected grid. Your own power generation might be insufficient or need maintenance. It's inefficient if everyone is storing their own power. So it's unclaer what the future of the power grid is. Should there be large grids, small grids or no grid?

There also resilience. Having small to medium local storage increases the stability of the grid.

Renewables and something like Iron-Salt battery containers, would be pretty efficient over all. Easy to roll-out, very safe.

We'll still need some sort of base load somewhere and backup to restart everything obviously. But the big giant power plants (with the huge capital costs, delays and NIMBY headaches) might become less necessary.

> the summer months (where your power bill tends to be higher anyway)

This depends on where you live!

Excellent points.

One wonders if this is why Lockheed-Martin dropped their effort:

https://www.lockheedmartin.com/en-us/products/compact-fusion...

(that page is still up, but news reporting indicates it has been dropped)

And the transmission costs argument is precisely why we'd likely be better off solving the problem of distributing power production across a more decentralized grid with a lot of wind and solar and battery all over the place

Problem: the capital & maintenance costs of the grid vary very little with its utilization %.

So if you build loads of wind & solar & battery all over - either (1) you've got to build so much battery capacity, all over, that you'll never need the grid, or (2) you've still got to build the grid to get you through occasional "calm & dark" periods.

Either way, you're looking at vastly higher capital expenses.

Not necessarily. A slightly different approach might become lower TCO in the medium term:

- moderately overbuild solar

- batteries for short term storage

- natural gas for seasonal storage

> transmission costs are half of your energy bill

Wait, what?

Wikipedia[0] seems to disagree:

> Long-distance transmission (hundreds of kilometers) is cheap and efficient, with costs of US$0.005–0.02 per kWh, compared to annual averaged large producer costs of US$0.01–0.025 per kWh

Do you maybe mean that half electrical energy dissipate between production plant and consummer? But that figure seems quite large compared to what I can find online, and this would not be a problem with "free fusion".

Care to explain?

[0]: https://en.wikipedia.org/wiki/Electric_power_transmission

I meant to say distribution costs not transmission. Looking at last months bill I paid $66.60 to deliver $51.76 of energy (about 56% of my total bill was delivery). The raw distribution charge alone was $49.32 or 42% of the bill. I'm not alone in these numbers, but your mileage may vary.

My point is that the infrastructure related to the delivery of energy to a physical location is a non trivial part of an energy bill, and that this part doesn't go away magically because "fusion".

Long-distance transmission, of huge quantities of electrical energy, IS very efficient.

Distributing tiny fractions of all that energy to each of millions of individual residences, then maintaining all the short/complex/low-capacity wiring needed to do that - that part ain't the least bit efficient.

Total losses on the US grid are about 6%, last I checked. It could be slightly more efficient, but only slightly.

Where I live I pay about $0.09 per kWh for generation and about that much for transmission as well. I think that's what they're referring to, the literal bill they get from their current provider.

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