Wind always blows somewhere, the sun always shines somewhere.
Making a global power grid is something which I don't expect anyone will do in the next 15 years, but if anyone does I'd be least surprised if it's China on a belt-and-road type project.
Batteries are necessary for electric vehicles, and I do expect >50% of land motor vehicles in use worldwide to be electric within 15 years of today; that scale is sufficient to invalidate concerns about intermittent renewable generation in most (but not all) places even without a global grid.
And how far of a cable would you need to get 24/7 solar power? Because based on my math, it would have to cross a lot of timezones - including ones with a lot of people that would be happy to chop that cable if it meant screwing with the US.
A single cable is a bad idea for many reasons, but "it might get cut" isn't one of them, as at this scale it's the kind of thing that the whole world is using, so (0) nobody actually benefits from cutting it, (1) it's carrying order of a terrawatt at any given moment, so if you made it a single cable the magnetic field alone will mess with your cutting equipment, and (2) for reasonable resistance it's a cross section of about a square meter (1 Ω and ~1 year global aluminium production for that cross section at 40,000 km), so even a literal detonation of a Little Boy nuke 500 meters from it wouldn't make a dent.
If the cable (or one of them: again it's bad to make it just one, just physically spreading out that 1m^2 into a hundred cables of 10cm by 10cm makes it a lot less risky) goes through Russia, and they cut it, the effect is that immediately Russia stops trading energy.
At best, this is a loss of income. At worst, it means their own lights go off because now they aren't getting anyone else's electricity in their own night and their own winter.
What exactly do you think is fantastical? Using one year's production of one element? Because I'd already noted that the political aspects are severe enough that it's unlikely for anyone to build at this scale any time soon, and that only one country would be capable but even then it would be a surprise.
I find it fantastical that anyone in the geopolitical environment would put themselves at the (near instantaneous) mercy of someone that far away - physically and politically.
We’ve already seen the games played with hydrocarbon pipelines, and hydrocarbons are easy to store in large quantities, which greatly reduces the risk of someone playing ‘got you!’ on something that literally is a matter of life and death.
It still - clearly - happens, but when it does it isn’t as urgent as freezing to death tonight if you don’t do what they want. Unless they’re also bombing your storage tanks, which does happen, but is a significant escalation over ‘oops, we hit the power cable with an anchor again. Sorry!’.
For the Russia example, in the situations Russia wouldn’t want to cut it - the US and China would love to! Or have a proxy do it for them.
And if Russia has enough battery storage to last a week or two (minimum to outlast a storm; and also more than adequate to deal with daily insolation variation), they don’t have much of a need for these cables either, correct? At least most of the time.
In fact, in those cases the cables would actually present a bit of a problem, as they would potentially cause economic/trade/currency balances, similar to the Oil trade, and make it less economic to actually have the appropriate degree of local storage and production necessary.
The same issues pop up even regionally - Europe has a history of not always being super peaceful, so if, say, the UK wants to run a HVDC line to Spain, they have to think long and hard about the implications. As does Spain.
Because if Germany does that they did a few generations ago, that cable isn’t going to last long, and if the UK doesn’t have adequate safe alternatives, then they’re going to have a really hard time fighting back. And if Spain decides to raise rates to ruinous levels of the UK ‘brexits’, what leverage does the UK have?
Let alone not freezing to death. And Spain needs to consider they might be broke in such a situation, and having a hard time paying their own bills.
And if they do have adequate alternatives, then why is it a big deal to have the cable? What does it actually offer?
As to if it’s a single cable or a million of them or a lattice or whatever - the big question is ‘why?’ when the rest of these factors come into play. The materials cost to build and maintain it doesn’t help either.
That all sounds like politics? If so, that's a point we agree on :)
None of that seems like physical issues, despite you mentioning that on the first paragraph.
> For the Russia example, in the situations Russia wouldn’t want to cut it - the US and China would love to! Or have a proxy do it for them.
If they have alternatives, otherwise they're all in the same boat whose name is "interdependence".
China's also the only country that seems to have any even slightly serious interest in attempting to build anything close to such a grid in the first place, as part of their own soft-power projection, and are the only country producing enough aluminium to attempt it anyway — half of all current global production is factories they switched on since 2006: https://international-aluminium.org/statistics/primary-alumi...
Nobody else but China will bother in the foreseeable future, and even China might not. (Which is yet another rephrasing of the same point I've been making throughout).
> And if Russia has enough battery storage to last a week or two (minimum to outlast a storm; and also more than adequate to deal with daily insolation variation), they don’t have much of a need for these cables either, correct? At least most of the time.
Sure, but a week of storage is at least* 14 times more expensive than overnight storage.
If you see your enemies building up a lot of storage without any clear reason, you know Something Is Up, just like if you see them amassing tanks on your border.
If they have a clear reason, "there is no power grid in the first place" being one, then it's harder to know they're doing something odd.
> And if they do have adequate alternatives, then why is it a big deal to have the cable? What does it actually offer?
Lower price.
I'm expecting batteries to get cheaper, but the current price is in the order of $100/kWh capacity, if they last 1000 cycles that's $100/MWh delivered*. If you have to size your battery packs for long-term use, be it Dunkelflaute or seasonal or military shenanigans, you don't get to discount that, it's what it is; but if you're only using it for emergencies, then those batteries don't wear down as fast just because you don't go through those cycles so often — how much depends on the duration and frequency of the emergency, and also how well your batteries cope whatever they do in a non-emergency condition.
A global mega-project is obviously going to be more expensive than the mere material costs; even the opportunity cost of what else they could do with the same resources is a huge question, and why it's heavily in the "politics and economics" domain rather than the mere physicality.
But the mere physicality that I'm openly and explicitly and repeatedly acknowledging comes with additional political difficulties**, that's a few hundred billion for a thing that lasts 75-120 years based on other examples; it would carry in the order of a terawatt continuously, 24/7, for about 1/250th - 1/440th the price of batteries: https://www.wolframalpha.com/input?i=%28239+billion+USD%29+%...
* Night has significantly lower demand: you've got 50% power demand, that's 1/3rd of the total daily energy demand from draining batteries, so they only add $33/MWh to the deliverable cost.
** It's frustrating that this combination is still ignored so often when I mention this physical possibility; how can I possibly be clearer that I know that all the other stuff besides actually building it is hard?
Politics cause physical issues. Like things getting bombed. And physical things like distance impact politics - it’s easy to blame a country on the other side of the world vs a neighbor (that people know), or ourselves, for instance.
And why it’s a fantasy is the large capex needs to be spent - while the period of least trust and apparent need exists. And a lot of distance needs to be built before it produces any potential value. And the physical issues. And the politics. And since the benefit comes from the long distances, this isn’t something that is ignorable.
If such a thing already existed, for instance, and countries were using it without abusing it, then being able to justify the cost - and not feel a need for lots of storage - is likely easy. And it’s easy to trust someone when you can see the actual economic incentives for them to behave, and have a track record of it happening. And if everyone is (actually) using it, then it is hard to pick one party (you) off without the whole group ganging up on the offender.
But without such a thing existing, everyone needs to worry about whoever is funding it (if a large country) abusing it to control them, or if everyone is funding it, some random country they don’t like throwing up roadblocks to stop the project actually working for them - and bankrupting them. And since it wouldn’t benefit all countries simultaneously (due to the physical difficulty in constructing such a thing), and it won’t even be actually useful until it is very long already, there is a larger risk of hard feelings and sabotage.
And since they would be dependent on it reaching so far, and countries being so far away playing nicely, the risk on that front is huge.
And the only meaningful way to mitigate that risk is to build lots of storage at a national level.
Which also removes the primary advantages of the project in the first place.
> What exactly do you think is fantastical? Using one year's production of one element? Because I'd already noted that the political aspects are severe enough
Do we stockpile the entire production of aluminium across the entire planet every year, and don't use it just because of politics?
Or do we actually use that yearly production in, you know, actual things that are produced from aluminium?
> only one country would be capable but even then it would be a surprise.
Even the magical country of China would not be able to put the stunt of converting 77 million tons of aluminium into a 40 000 kilometer-long power cable.
> Do we stockpile the entire production of aluminium across the entire planet every year, and don't use it just because of politics?
Aluminium production is not fixed, it varies by demand; I'm suggesting a trivial increase in production given how long power lines last.
> Even the magical country of China would not be able to put the stunt of converting 77 million tons of aluminium into a 40 000 kilometer-long power cable.
It's not harder than anything else that's made of the same stuff.
You know we get the stuff from rocks, right? It doesn't come out of the ground pre-formed as cans and car doors… well, unless you're digging in a landfill.
> How many 44 000 kilometer cables with a cross-section of 1 meter have we produced so far?
Assuming you continue to ignore that that's the aggregate cross section and that the resistance is identical if it's one single cable that size or a hundred of 10cm by 10cm?
And also ignore that all things on this size are normally done by making small things and joining them together?
For the dry bits, dig a trench and pour liquid metal into it.
And for the wet bits, make a 'trench' out of concrete and pour liquid metal into it.
Heck, given how aluminium is produced, you could even dig the trench, fill it with ore, and electrolytically reduce it from the oxide in situ.
But the traditional approach is probably going to be of more interest to investors. Less risk, and you get benefits from the sub-systems without having to complete the whole thing before seeing anything.
> I very much doubt that you do
You doubt that I know the thing I just told you in the line you're quoting to say that you doubt it?
> Not inherent nature, just economics and politics.
I didn't know that night and calm days with no wind are economics and politics
> Wind always blows somewhere, the sun always shines somewhere.
Key word: somewhere. How much wind and sun needs to shine somewhere to cover the needs of, say Europe, on a quiet night? Note that that somewhere will need to cover that somewhere's needs, too.
I'm guessing your proposal is to pump energy from China to the US through the Pacific Ocean?
> Making a global power grid is something which I don't expect anyone will do in the next 15 years
Or ever. You underestimate the size of the Earth
> I'd be least surprised if it's China on a belt-and-road type project.
You know that Europe has a unified power grid, right? And that the US has three major grid regions?
> Batteries are necessary for electric vehicles, and I do expect >50% of land motor vehicles in use worldwide to be electric within 15 years of today; that scale is sufficient to invalidate concerns about intermittent renewable generation in most
wat?
Just because you have batteries in electric vehicles doesn't mean you have enough batteries to provide electricity for a country/continent.
> Note that that somewhere will need to cover that somewhere's needs, too.
And our day provides their night.
It's called "trade".
> you're also likely underestimating how large the area covered by nighttime
Your links are, bluntly, an insult. Everyone here knows the thing they show.
~50% of the planet technically, more than that in practice because local structure; average capacity factor (24 hour including night) of PV is 10%, so I'd be happy to approximate that as a 12 hour day-focused capacity factor of 20%.
> I'm guessing your proposal is to pump energy from China to the US through the Pacific Ocean?
China has an actual proposal for a demo project to go further across the Pacific and connect to Chile.
If that works, they might feel like making it thicker and longer.
> Or ever. You underestimate the size of the Earth
40,000 km, requires 1 m^2 cross section to keep the resistance down to 1 Ω when using Aluminium; this requires just over a year of current global production of aluminium and has a material cost of a few hundred billion dollars at current metal prices.
> You know that Europe has a unified power grid, right? And that the US has three major grid regions?
Which is why it's a political problem. There will always be a place like Texas is now that wants to be difficult and independent even at its own expense.
> Just because you have batteries in electric vehicles doesn't mean you have enough batteries to provide electricity for a country/continent.
There's approximately a billion cars on the road today.
Half a billion cars multiplied by let's say 60 kWh per car is 30 TWh; current global electricity use (which includes daytime) is about 2 TW, that's therefore 15 hours before I include trucks, bikes, busses, etc.
But night use is lower than day use, so in practice the capacity to build that many batteries is also the capacity to build enough batteries for overnight use too.
> I've seen EU night power draw is about 87-107 GW, so 85% of the area of Rhode Island but in Australia
And what's your proposal for getting that energy to the EU from Australia?
> And our day provides their night.
And who's providing your day if you're busy providing someone else's night?
> Everyone here knows the thing they show.
Oh, I doubt it. I keep seeing how people keep pretending that night doesn't exist or how it's easy to provide EU's electricity from Australia during the night.
> 40,000 km, requires 1 m^2 cross section to keep the resistance down to 1 Ω when using Aluminium; this requires just over a year of current global production of aluminium and has a material cost of a few hundred billion dollars at current metal prices.
For a single cable with no redundancy, unknown points of ingress/egress and how to handle that much power in those points of ingress/egress etc. And not pricing in the cost of actually making such a cable, and the cost to actually lay it securely, maintenance costs etc.
> Which is why it's a political problem.
I'm still waiting to hear an actual solution to getting continuous 107GW of power from Australia to the EU. Oh, at the same time keeping up with fluctuating energy demand, frequencies etc. And not a fantasy of redirecting Earth's entire aluminium output to building a single 40 000-kilometre cable.
> Half a billion cars multiplied by let's say 60 kWh per car is 30 TWh; current global electricity use (which includes daytime) is about 2 TW
Something tells me those cars need to be charged somehow, this is probably done by another 40 000 km cable from Australia.
> China has an actual proposal for a demo project to go further across the Pacific and connect to Chile.
Quick googling didn't reveal any such proposal for a ~12000-kilometre cable. The longest proposal is to connect Morocco to Britain with a 3800-kilometre cable, and even that will be an engineering feat of epic proportions if it's not scam/vaporware
> And what's your proposal for getting that energy to the EU from Australia?
Are you trolling? Obviously the same. Why would it possibly be anything other than the same?
> And who's providing your day if you're busy providing someone else's night?
Again, are you taking the piss? Because the only way you're not trolling here, is if you're guilty of what you accuse me of: You underestimate the size of the Earth.
There's plenty of room to do both.
As in, several thousand times over.
> Oh, I doubt it. I keep seeing how people keep pretending that night doesn't exist or how it's easy to provide EU's electricity from Australia during the night.
If you're constantly arguing with a whole host of other people, which is more likely: that they're all idiots who don't know about one of the more fundamental aspects of living on a planet, or that you're misunderstanding their points?
Hint: I did not say "easy", I said "I don't expect anyone will do in the next 15 years" and priced it at hundreds of billions of dollars and even then requiring political collaboration.
15 years is the minimum time in the best case, not the default.
> I'm still waiting to hear an actual solution to getting continuous 107GW of power from Australia to the EU.
You've already got one.
> Oh, at the same time keeping up with fluctuating energy demand, frequencies etc.
DC.
> And not a fantasy of redirecting Earth's entire aluminium output to building a single 40 000-kilometre cable.
Output for one year for something that, from other examples, lasts about a century.
> Something tells me those cars need to be charged somehow, this is probably done by another 40 000 km cable from Australia.
Again, are you trolling? Because that was an alternative to a global power grid.
If you've got those batteries then because the battery is itself the storage system it doesn't care when it gets charged, so it doesn't matter if you can only charge them in your own local daytime as they last through the night and to the next day (and for most people, days plural) anyway.
> This also assumes that all of those cars and busses and trucks are somewhat continuously and consistently plugged into energy grids, with no disruptions, which is not true:
It's not making any such assumption, it's the capacity to build that much battery in the first place, not where the batteries actually are.
> Quick googling didn't reveal any such proposal for a ~12000-kilometre cable.
> The longest proposal is to connect Morocco to Britain with a 3800-kilometre cable, and even that will be an engineering feat of epic proportions if it's not scam/vaporware
Epic, yes.
That's why I'm setting the minimum time for a global grid as pessimistically as 15 years, even if it's made by a government that has a history of using this kind of project as a soft-power projection policy, that already has a project of this kind in planning, and using (1 year/15 years = 6.666…%) ~7% of the aluminium that the world would otherwise be expected to produce in that timeframe.
I was going to write a long reply, but I decided against it.
Because I'm frankly tired of buffoons ignoring the basic realities like physics and geography and pretending their wishful thinking is "trivial to implement".
I mean, you're so detached from reality that you already claim that a vanity project announced by Chile is an actual leaving breathing existing project to which China has already committed.
I don't have the time arguing with people in denial about the basic realities of the world they live in.
Indeed, and likewise (well, the would not have guessed part, I'm not an EE).
It seems a really weird coincidence that the circumference of the planet happens to so closely match the resistivity of aluminium and the unit we use for resistance:
You cannot power up solar panels at night, or wind turbines when there's no wind.
As for nuclear, you don't need to stop them. Instead they provide a base load so you don't need to ridiculously overprovision other power sources. And they are flexible enough to go 50%-100% quickly: https://www.oecd-nea.org/upload/docs/application/pdf/2021-12...
We just need to install more panels to harvest the incoming radiation.