Solar power has begun to transform the world’s energy system

Plausible alternatives to cables include ships full of synthetic diesel, ships full of iron, ships full of aluminum, or ships full of magnesium. Inside China HVDC cables are indeed carrying solar power across the continent, but the Netherlands have not managed to erect any yet. Cables provide efficient JIT power delivery, but they're vulnerable to precision-guided missiles, which Ukrainians are 3-D printing in their basements by the million, so the aluminum-air battery may return to commercial use.

There's at least one HVDC cable connected to Netherlands, Norned: https://en.wikipedia.org/wiki/NorNed .

As probably everyone knows, Netherlands is very flat and Norway very mountaneous. Norways is also very rainy. So it's a match made in heaven - Norway's mountain reservoirs can act as balancers for dutch wind power.

Ships carrying energy are a pretty easy explosive target as well.

Local ressilence is needed in any case and mass produced batteries can provide that safety.

And to Denmark:

https://en.wikipedia.org/wiki/COBRAcable

While Denmark in term essentially is a trading hub for electricity between Scandinavia, the UK and continental Europe.

The Netherlands has “erected” multiple HVDC links

As long as we all realize you can’t 3D print precision-guided missiles without, well, the guidance bit.

As well as electricity to ammonia, ship it around the world by boat and then crack or burn it at the destination. or just use it as-is.

>Budgeted at €550 million, and completed at a cost of €600m

Amazing.

That's pretty good! Just a 10% overrun. By comparison, Hinkley Point C is now at "up to" £46bn from an initial £18bn. https://www.bbc.co.uk/news/business-68073279

Diesel, iron or aluminum, from your parent post, are difficult to explode… (personally, no clue about magnesium); and the point of the latter two is that you can “store” energy by upstreaming its consumption when power is available, you don’t necessarily need to produce an actual reversible energy store.

magnesium is the most explody of all those

> and the point of the latter two is that you can “store” energy by upstreaming its consumption when power is available

Are you sure the parent isn't referring to something like a rust (iron-air) battery? Aluminum, Iron, and Magnesium are all viable battery chemistries.

Side note - I'm pretty certain you don't actually need to make contents of a ship explode to easily sink it with explosives.

I'm actually somewhat concerned that between drones and smart mines - we've never had a better chance of completely ruining our ability to do ocean based shipping during combat.

Ukranians are 3d printing millions of missiles in their basements?

Which is a fair comparison because 700MW is a smallish nuclear reactor and that cable should last a long time.

They might use rotating wings to fly instead of jet turbines, but yes.

EDIT: To make things clearer, the word Missile is quite old, and predates rockets. missile is any object that is propelled somehow to hit a target. So even a stone launched from a sling by a caveman is already a missile. The other guy mentioned precision guided missiles though... and he is still correct in the word usage there.

I don't know, I'd say once you reach a certain amount of control over your flight path you stop being a missile. An aircraft isn't really "projected toward" something.

But still not explosive at scale. It’s a surface area issue, a small strip of magnesium explodes when dropped in water but a 100t cargo of magnesium sinking in a harbor would be a huge fire.

Cruse missiles have a great deal of control over their flight. “Kamikaze aircraft were pilot-guided explosive missiles, either purpose-built or converted from conventional aircraft.” https://en.wikipedia.org/wiki/Kamikaze

However, the distinction is usually applied where aircraft become missile’s when the attack can no longer be aborted.

If I look at the number of 90 degree turns a cruise missile can make and compare it to an airplane I wouldn't rate it very highly.

> However, the distinction is usually applied where aircraft become missile’s when the attack can no longer be aborted.

So for a quadcopter that's a pretty negligible amount of time. And not all that much for tiny planes either.

The SM-62 Snark had a 10,000km range so presumably thousands of 90 degree turns were possible. What the actual guidance software could do may have limited it.

> a small strip of magnesium explodes when dropped in water

No it doesn't.

Magnesium metal burns because the boiling point of magnesium is just 1091 C, so extremely reactive vapor is readily produced. But it would be very hard to heat it that high in water unless it was ignited first. It will then continue to burn under water.

The guidance bit should be quite cheap now though, compared to decades ago. Some combination of MEMS backed up with GPS.

Thank you for the correction! It's also immune to quadcopters.

Thank you for the correction! That one is immune to quadcopters too.

Yes, ammonia is another candidate.

Yes, it's easy to imagine cases where people go around sinking ships; narcosubs, Red Sea oil shipping, and Russian warships in the Black Sea are of course dealing with that threat currently, but as hostilities escalate it's likely to increase. But energy in the form of shipped fuel intrinsically provides some minimal level of such local resilience—for it to work, you need at least a stockpile of fuel big enough to last until the next ship is expected to unload, which is orders of magnitude longer than the milliseconds before a cable cut affects you—and can provide arbitrarily large amounts of it.

The metal fuels in particular have the merit that you can use them in precisely such mass-produced batteries rather than to produce thermal power. As I alluded to in my grandparent comment, aluminum-air batteries were mass-produced in the 01960s.

We have quite a bit of experience transporting hydrocarbons . . . .

Maybe I should have clarified burning, as in “Why does burning magnesium explode when sprinkled with water?”

https://physics.stackexchange.com/questions/33167/why-does-b...

And software. The Ukrainian drones largely run on the open-source Ardupilot.

GPS is fairly easy to jam, and despite the purported end of Selective Availability, unencrypted GPS can be turned off entirely without affecting US military GPS. Cruise missiles have been using terrain models for decades now, since well before GPS (a major reason high-resolution DTED used to be classified) which just requires a computationally cheap particle filter and appropriate sensors. We can expect belligerents in upcoming conflicts to maintain strategic stockpiles of the relevant electronics, which are more compact than even cocaine or fentanyl and therefore difficult to blockade.

Yes, safety is a significant disadvantage of the use of magnesium as portable stored energy, but if your ship's payload is already on fire, in most cases the shipment will not be very successful anyway, and loss of the ship is a serious possibility.

If a hypothetical ship full of magnesium sinks without catching the magnesium on fire first, the magnesium will probably not catch fire from exposure to water. Perhaps if it's sufficiently finely divided, which seems like a bad idea.

We do, but even in peacetimes not without issues.

https://en.m.wikipedia.org/wiki/List_of_oil_spills

But the problem mentioned above was about war.

You may have seen that Colombian drug cartels are already using Starlink-piloted "sea drones" to do ocean-based shipping through blockades. The US Coast Guard estimates that 90% of crewed narcosubs get through: https://www.youtube.com/watch?v=5aPLXdtbLZ0

I agree, the point is you’re not risking something like:

https://en.wikipedia.org/wiki/Halifax_Explosion “At least 1,782 people, largely in Halifax and Dartmouth, were killed by the blast, debris, fires, or collapsed buildings, and an estimated 9,000 others were injured.”

“Nearly all structures within an 800-metre (half-mile) radius, including the community of Richmond, were obliterated.[3] A pressure wave snapped trees, bent iron rails, demolished buildings, grounded vessels (including Imo, which was washed ashore by the ensuing tsunami), and scattered fragments of Mont-Blanc for kilometres. Across the harbour, in Dartmouth, there was also widespread damage.[4] A tsunami created by the blast wiped out a community of Mi'kmaq who had lived in the Tufts Cove area for generations.”

Also depending on how many corners you're willing to cut. Half the cost but a 1% chance that it turns around and targets a friendly? Some countries would take that trade.

Like the Apex boats in Operation Dragoon.

https://www.oldsaltblog.com/2024/08/apex-boats-the-unlikely-...

"On the landing beach at Baie de Pampelonne, most Apex boats exploded against the obstacles. Nevertheless, one ran aground, and one sank. A third reversed course and turned back out to sea before exploding near Sub-chaser #1029 and severely damaging it."

One could argue all those Mk 14 torpedoes that malfunctioned and went onto circular paths also counted.

Not with magnesium ingots or dry magnesium, no; but, because the water–magnesium reaction is exothermic, spontaneous, and gas-producing, I'm pretty sure there's a range of ratios where wet magnesium does constitute an explosive if it's finely divided, at least a low explosive like gunpowder, so such an accident could happen.

It seems unlikely to happen by accident because at stoichiometry you need more water than magnesium, and I don't think spontaneous explosion is a real risk with magnesium. The International Magnesium Association's safe handling guide https://cdn.ymaws.com/www.intlmag.org/resource/resmgr/safety... does mention that magnesium swarf can spontaneously combust in the presence of water, but I think swarf is too coarse to explode. It recommends keeping wet magnesium swarf under water to prevent it from heating up enough to spontaneously ignite.

But presumably you'd be shipping the magnesium in the form of plates, ingots, or rolls rather than powder, swarf, or loose foil.

I think the idea of "peacetime" is probably outdated. Not in the sense that I think people should fight, but in the sense that their fighting will no longer be limited to certain geographic areas, and people will fight, so all of us will be at constant risk of both infrastructural damage and violent death.

Even magnesium powder wouldn’t detonate when you’re talking tons of the stuff on a boat for the same reason small hydrogen balloons can go bang, but the Hindenburg just created a huge conflagration. You get limited mixing due to the volumes of material involved. Even burning across several seconds is just vastly less dangerous than an actual detonation.

Same issue with grain silos exploding because of the mixture of fuel with oxygen, but flour just burns etc.

Yes, that's why I said, "dry magnesium, no". A pile of dry magnesium powder only burns at the surface as air diffuses into it. If you have it mixed with the oxidizer so that the flame can propagate through the whole mixture, it will, and the propagation speed is determined by factors like the reaction speed, gas production, and thermal conductivity. The reaction speed in turn is governed by the particle size, since the reaction only takes place at particle surfaces; it goes to completion faster when particle size gets smaller.

Small hydrogen balloons do not in fact go bang; they just create small conflagrations. What goes bang are small balloons filled with a near-stoichiometric mixture of hydrogen and oxygen, such as you get from the simplest forms of water electrolysis.

The stoichiometric mixture of magnesium with water is 1.36 grams of water per gram of magnesium (which is 1.74g/cc, so this 58-wt%-water mixture is 70% water by volume), the enthalpy of formation of H₂O is -285.83kJ/mol, and the enthalpy of formation of MgO is -601.6kJ/mol. So this reaction:

    Mg + H₂O → MgO + H₂

yields 315.8kJ/mol, which is to say, 315.8kJ per 24.3 grams of magnesium, or per 58 grams of mixture, about 5.4MJ/kg, about an 18% higher energy density than TNT. And the hot hydrogen gas produced will carry the heat produced by the reaction into nearby areas, igniting them and resulting in a flame propagation velocity that's higher than thermal conduction alone.

For a large enough particle size, you won't get an explosion, and you may even lose most of your water as steam; but for a small enough particle size and an oxidizer concentration close enough to stoichiometric, you will. Some nanothermites consisting of magnesium nanoparticles with an oxidizer such as iron oxide even reliably detonate.

So, it's a potential safety hazard, but it seems like one that should be easy enough to guard against.

> for a small enough particle size and an oxidizer concentration close enough to stoichiometric, you will.

Sure but nobody is going to ship large quantities of magnesium like that: “Use proper packaging: Ensure the magnesium is sealed in moisture-proof, airtight containers.” https://www.freightamigo.com/blog/hs-code-for-containing-at-...

> Small hydrogen balloons do not in fact go bang

It’s not a supersonic detonation but even normal balloons pop with a small bang, pure hydrogen balloons are louder. Though a you mention hydrogen + oxygen is significantly more extreme.

It's good in its adherence to the budget (almost) and maybe its absolute price: €600M for 700MW is €0.86 per watt. That might sound terrible when compared to current mainstream solar panel wholesale prices of €0.11/Wp, but solar plants in the Netherlands have a capacity factor of only about 10% IIRC, so that is €1.10 per average watt, not counting balance of plant, permitting, etc. The cable may not run at a 100% capacity factor but it'll probably be over 50%.

Still, if module prices continue falling, even at poor capacity factors lime 10%, it'll be increasingly hard to justify paying such high prices to move energy around the continent; local overprovisioning and storage will be cheaper even if Norway is willing to produce the energy for free.

I don't think peacetime is outdated, but we do live in a time of increasing tensions and classical and asymetric conflicts, mixed with an increasing amount of people who believe they have nothing left to loose. So yes, I also prefer the concept of local ressilience as opposed to having many critical infrastructure points where everything else will collapse if those are damaged. Solar, Wind and batteries can go a long way here, to keep at least critical systems running.

The autonomous boat got intercepted on a test run.

Sure but moving from a few centralized sources of fossil fuels to a globally distributed and decentralized network of sources of synthetic biofuels means transport distances are a tiny percentage of what they are with fossil fuels.

This consequently scales down the scale of any spill or security issue.

Like the difference between nicking a capillary and nicking an aorta.

> ships full of iron

At first I thought you meant "embodied energy" or some such.

Iceland "exports" geothermal energy by converting bauxite ore into aluminum.

Australian could "export" renewable energy by domestically converting iron ore into steel.

Yes, but remove the scare quotes; I'm talking about exporting those materials to people who burn them for energy, in most cases in batteries. The round-trip efficiency of that process is not great, but I think should be around 70% for aluminum, and better for iron and magnesium; and the specific energy (MJ/kg) for those metals is significantly better than for conventional hydrocarbon fuels.

What?

I don't think any of tensions, classical conflicts, asymmetric conflicts, the amount of people with nothing left to "loose", or all of these together, are at particularly unusual levels compared to the previous 6000 years, though they're higher than they were 20 years ago. But, for most of that time, warfare was geographically localized; you could avoid directly experiencing warfare by not being a soldier and living inside a country that wasn't being actively invaded, or on the national border between two countries that weren't at war with each other or being actively invaded. Sometimes that was easier said than done, but most people managed it most of the time.

In the Drone Age, though, you can remotely pilot a quadcopter 4300 km away to blow up airplanes on the airstrip: https://en.wikipedia.org/wiki/Operation_Spiderweb — or to blow up your political opposition, if you can guess where they are or will be. The US has been doing this for 20 years in Afghanistan and Iraq: https://theintercept.com/2015/11/19/former-drone-operators-s... (use Readability mode to bypass "this is not a paywall") but a General Atomics MQ-9 Reaper costs on the order of US$100 million, so there are less than 400 of them https://en.wikipedia.org/wiki/General_Atomics_MQ-9_Reaper#In... while Ukraine's most popular drones cost on the order of US$300, can be 3-D printed in a basement, already cause 70% of casualties on the battlefield, and are produced in volumes approaching 10 million per year https://www.nytimes.com/interactive/2025/03/03/world/europe/.... Many experts believe drones have made tanks obsolete on the battlefield https://www.youtube.com/watch?v=YJRqXBhnvCs.

Even without autonomous weapons, we're rapidly moving toward the future of borderless war without end so vividly envisioned in Slaughterbots https://www.youtube.com/watch?v=9CO6M2HsoIA. Ukraine is already an order of magnitude past the headline number it opens with, "Customer pilots directed almost 3,000 precision strikes last year."

If you want to see what precision strikes on the Ukrainian battlefield look like, plenty of Ukrainian military units have posted fundraising videos, so you can watch terrified conscripts dying all day long if you want to: https://www.youtube.com/watch?v=OjIgTJ-73v4 https://www.youtube.com/watch?v=qhQBf4VFMwI https://www.youtube.com/watch?v=A64TmBvbn1Y https://www.youtube.com/watch?v=kXUqJAnAP9c https://www.youtube.com/watch?v=ZCoCxARDEio.

Those videos are a preview of what life will be like for you and your family in the years to come as war becomes borderless.

I appreciate the correction.