[ben_w]

Not trolling, political reality.

Speaking personally, I'm fine with nuclear power near me as a part of a grid — even despite the high monetary cost — because I'm satisfied of the safety and I think supply diversity is worth paying more.

But nuclear is a boogieman, and that means the reactors are slow and expensive to build.

The geopolitical risks also mean other countries may look at your reactors as an existential threat — this is also a thing the governments need to care about no matter how sure they are that they're the goodies and everyone else is being silly when raising such concerns.

And while an earthquake was the ultimate cause of the Fukushima incident, it wasn't the proximal cause: Germany does get floods from time to time.

Of course, if I get to ignore politics then my favourite is a global power grid energised by PV — the maths says that would be great, though it would take a while to build.

[_hypx]

The political reality of Germany is still that of climate change denial. Worse, environmentalists are effectively part of that group.

Eventually, this will change. You cannot denial reality forever, and especially not of existential problems.

[ben_w]

> You cannot denial reality forever, and especially not of existential problems.

Oh yes you can.

Or at least, long enough for it to be terminal. Thinking you can't possibly fail is a common reason for failing.

The Titanic being [un]sinkable comes to mind, but it's hardly the only case of such hubris.

[_hypx]

So you're literally predicting the end of the world. Great.

[ben_w]

Not in this case I'm not — I'm saying here that "nuclear won't save it", which is different, especially as there are many other solutions.

You yourself elsewhere on this post are promoting hydrogen storage (I wish all the luck to whoever is working on that); I'm personally in favour of a global power grid; there's a bunch of fusion startups that may or may not get past the political hurdles plaguing fission even if/when they succeed at net power; genetically engineered bio-oils are also a possibility (as feedstock not just as fuel!); geothermal and tidal are also renewable but not seasonal.

But on the other hand, I am worried about non-aligned AI, about biodiversity loss, about peak phosphorus, and a whole bunch of other things.

[_hypx]

A global power grid is a far greater fantasy than building hydrogen storage, just FYI.

[ephbit]

There's a key difference between the current - mostly chemicals (coal, oil, uranium) based - system of providing people/machines/devices all over the world with energy and some proposed system where most energy is delivered in the form of electricity, generated from renewable sources.

Using chemicals to transport energy immediately leads to greater resilience because these chemicals always have a buffering effect, so they can buffer shorter and longer disruptions.

Many people appear to not have this in mind, when they propose a global electrical grid to power almost everything. An electrical grid is much more fragile than a chemicals based transportation system.

As soon as we see the first big tankers transporting green ammonia all over the world, say from Namibia or Australia or wherever, each one of these will contain weeks worth of ammonia (for some industrial site or whatever), which will mean added resilience since there's no one pipeline that can be damaged. Ships can flexibly go from any one to any other port.

But not only that. Due to the high energy density of chemicals, the chemical transportation system also has a much higher capacity than HVDC. Several ships can go from one place to another at the same time, and queue up at the point of arrival, while electricity from two sources to one destination would add up at some point in the grid.

Example:

> .. the vessels could carry about 58,000 tonnes of ammonia .. [1]

58,000 tonnes x 22.5 MJ/kg = 362.500.000 kWh = 362.5 GWh

Assuming a power generation efficiency of 0.4 (-> 145 GWh electricity), this is roughly equivalent to a 1 GW powerplant delivering power for 6 days.

Imagine trying to transport 145 GWh from Australia to Europe, or even just from windy Greece to Germany with HVDC. You'd need the 100 % capacity of a 2 GW HVDC line (1500 km long) over 3 days to transmit it all, during which this line could not be used for any other transmission purpose.

[1] https://www.icis.com/explore/resources/news/2021/08/10/10672...

[ben_w]

Only because of the politics (if Texas can't get out of its own way, what chance international coordination?), and in that regard the comparison is "why not nuclear when it works?"

The tech is already known, the boring standard models of HVDC cable are good enough, the time it would take to build that capacity of cables is large but not ridiculously so.