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Comment by jocaal

1 day ago

Power travels near the speed of light. In theory, the entire globe can be connected and countries with daylight can supply those at night in a cycle.

This isn't going to happen simply because it would introduce enormous strategic vulnerabilities. The first act ina war would be to sever an opponent's grid connections to their neighbors because that would massively erode their ability to maintain an orderly civil society.

  • This won't happen because the lines are bi-directional. It would be like chopping off their own energy supply. Because of the Earth's rotation, neighbors can take advantage of each other's sunlight. Parts of Europe and North Africa's energy markets are already working on this.

    For the past 100+ years, the US has been spending a significant amount of money on protecting oil supplies to protect its oil billionaires and its economy. It's the #1 budget item, outspending the combined military spending of the next 10 economies. This can be reduced to zero, and ultimately, the $ 39 trillion deficit can be eliminated.

    • Bidirectional powerlines make the grid more stable for tha larger region around most countries because it makes it easier to route around the conflict as far as capacities permit. Not many countries span coast to coast in a way that couldn't be routed around. So that would actually increase the vulnerability of individual countries.

      The EU is actually extremely special because its souvereign member states collaborate in almost all areas on a level that is unmatched anywhere else. But the ideological foundation is getting eroded by propaganda and if that assault is effective, Europe will balcanize again and end up experiencing many more armed conflicts.

  • Or if everyone depends on another maybe we will not go into a war with each other.

    • Well, power dependencies would be uni-directional, not bi-directional.

    • People believed this before. Then WW1 happened. 100 years later, people forgot the lessons of the past, and believed this again. Then Russia invaded Ukraine.

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We would need impractically high voltages to minimize power loss over long distances.

Maybe something like microwave transmission or cheap superconductors will solve it.

  • The loss is not that much - approximately 3.5% per 1000km. IIRC the Changji-Guquan HVDC line reported around 8% over 3300km thanks to working at 1100kV.

    Extend that to 10k km and you're looking at approximately 25%, but if it's surplus solar, who cares?

    Such a line costs as much as a highway broadly speaking, so it's not impossible to build.

    • For reference, that would give me in Maine the ability to buy power from a solar farm in Arizona or other literally unutilized deserts.

      Local power costs are over 30 cents per KWh, so that could be pretty competitive.

      The problem is that, no profit based organization will ever build "surplus" solar to enable that kind of thing. If we want surplus power, if we want a strong grid, if we want cheap power, if we want to enable the ability to quite literally waste solar power on inefficient processes (including things like industrial processes that produce less CO2 or generating hydrogen or methane as long term energy storage), we have to get the government to make it happen

      But, uh, we hired people who would rather spend $170 billion on harassing random cities and brown people so..... Everyone get ready to pay absurd rates for electricity to support outdated businesses that have been directing American energy policy since Reagan, including paying about 60k coal miners in west virginia for a resource that is economically inferior to other fossil fuels but because they voted for a democrat once they now get a stranglehold on the US economy.

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Regional grids are connected via tie-lines, and I heard international grids are also starting to become more connected in this way too. Though, I'd imagine it's complicated to send power from one side of the planet to the other. For starters grids can have different frequencies that need to be converted between. Also all transmission lines are subject to loss factors. In addition all the intermediary transmission companies have to route the power and avoid congestion on their grids, Then you have deal with all the financial settlement of the wheeling charges, which if you have to go through multiple grids and multiple currencies sounds like fun to deal with.

My understanding of the intentions of connecting international grids is for things like emergency supply of electricity to a different grid to stabilise the frequency and prevent blackouts.

Do we have good enough conductors for that?

  • Utility conductors are just aluminum wrapped around a steel core, air is the insulator. You can theoretically handle voltage drop with larger conductors, and there are probably ways to ‘boost’ power over a long transmission line run. I deal with electrical wiring past the utility service entrance and am not super familiar with the utility side so perhaps an EE who works on the grid can chime in with more detail.

    I also know breakers for HVDC are extremely challenging to make, AC power has the benefit of sine waves crossing the zero line so power can be switched/broken a lot easier than with DC.