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Comment by arcticbull | Hacker News Reader

> Some absurd level of energy loss occurs in those.

It doesn't really - because we do the transmission at very high voltage, and the power loss is proportional to 1/V.

Power loss in transmission in the US is about 5%. In the transmission lines themselves it's only 2-4%. [1]

If you ran a power line all the way across the entire continental United States, you'd still get about 80% of the power out of the other end. The longest economically effective distance you can run an AC power line is about 2500mi, and DC around 4300mi. [2]

[1] https://chintglobal.com/blog/how-much-power-loss-in-transmis...

[2] https://en.wikipedia.org/wiki/Electric_power_transmission#ci...

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"Depending on voltage level and construction details, HVDC transmission losses are quoted at 3.5% per 1,000 km (620 mi), about 50% less than AC (6.7%) lines at the same voltage."

https://en.wikipedia.org/wiki/High-voltage_direct_current

This seems pretty significant. We don't have much losses because we don't transmit energy over long distances. But now we could.

We definitely do, we just don't want to pay to string up wire thousands of miles, let alone superconducting wire. The difference between keeping 98% of the power that goes through a wire, or 100%, isn't the reason we don't do it. To quantify it further, the current US grid loses 5% to transmission losses which is just less than a cent per kWh.

Most power is generated in a centralized way anyways because it's much more efficient that way. The 'dregs' aren't connected because putting up the wire costs far more than the extra power yields. A few percentage points more efficient won't change the economics, especially if the wire is (a) lead and (b) dramatically more expensive.

3.5% per 1000km is respectfully, basically nothing. You'd get 85% of the power out of a line from SF to NY.

I'm not saying there aren't use cases for room temperature superconductors, I'm saying this is not one that's going to be top of the list.

> 3.5% per 1000km is respectfully, basically nothing. You'd get 85% of the power out of a line from SF to NY.

But why connect SF to NY - what's the advantage? What about connecting a place where it's midnight with a place where it's noon? That'd allow you to use solar arrays instead of local coal/gas/nuclear power plants.

I think you're missing the point of why we make power grids instead of simply having city local generators or stations.

The whole purpose of interconnecting power generation sources is to be able to accommodate for dynamic demand and ensure resiliency.

AC Power networks are sort of similar to how the internet works. The high voltage transmission lines are like the transit lines or "backbone" of the internet.

Those lines connect power stations which are sort of like ISPs in that they deliver the last mile power to the end user.

Our modern society basically instantly stops the second we are unable to meet demand for electricity, so we design these systems in a way where redundancy is supposed to be ensured.

This isn't always the case though. Texas is a great example of a completely messed up electrical grid that is insufficient to support its populous. It causes deaths in heatwaves and freezes almost every year now.

It's not just about transmission losses, though over time those add up. It's also about the cost of the rest of the infrastructure, which is in part because you're dealing with very high voltages and the various step-up/step-down requirements depending on what you're trying to do (long haul, local grid, last mile).

That's included in the 5% number btw. AC transformers are incredibly efficient.

In the loss calculations, not in the capital cost. Transport costs are a function of losses and amortized capital costs (and profits...). A huge part of power grid costs is because of all of the infra dealing with different voltages and transforming between them.

Totally. But I don't think we're anywhere close to knowing what the cost of LK-99 wire is to make a comparison.

That's true, we don't know what it will cost, we're not even sure it can be done at all... But HVDC as it is already in use uses very expensive cable as well so the gap could end up being smaller than you might think at first glance.

https://global-sei.com/technology/tr/bn84/pdf/84-10.pdf

This is state of the art, note the different deployment options, including pressurized ones.

Maybe they will make superconducting transformers instead of cables

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