My country is going to commit economic suicide ...

[apis]

EVs could come with a spare battery, that way the spare can be charged during peak production. When you get home you replace the spent one in the car with the charged one. That way it also solves the long charging time problem.

Coal and nuclear can ramp up within minutes (hydro within seconds). So coal can adapt as long as the changes isn't too sudden (and unforeseen). Sunset and sunrise can be predicted very accurately, you can probably also predict how the cloud cover will change over the solar panels the next 20 minutes or so that would be necessary to make adjustments in advance.

The fuel pebbles in the pebble bed reactor use graphite as moderator, but the pebbles are encapsulated in silicon carbide which prevents the possibility of them catching fire. The reactor is self moderated and will not go above about 2000 C even if cooling fails, which the structure can deal with. No risk of steam explosions or buildup of hydrogen like you have in a water cooled reactor. If it's helium cooled, the helium is inert and also prevents any chance of fire. Helium can't chemically decompose into a stoichiometric mixture of H₂ and O₂ like water can. I've read that the german THTR reactor had some problems that made it uneconomical but there are other successful pebble bed reactors in the world. Anyway, I trust the nuclear physicists can figure out what is the best design.

Just read about a nice Canadian reactor design called slowpoke-3, that seems very safe and was intended to provide district heating, unfortunately anti-nuclear protests killed that one as well. Much nicer with a good old cosy coal furnace apparently.

[nctnico]

EVs could come with a spare battery, that way the spare can be charged during peak production. When you get home you replace the spent one in the car with the charged one. That way it also solves the long charging time problem.

But you'd need the most expensive part of an EV twice making EVs even more uneconomical than they already are.

[apis]

More expensive than ICEs are today perhaps, but it would still be a solution for those that need a car. Assuming you can wear out both batteries during the lifetime of the car the overall cost isn't higher. I.e. if you have to replace the battery once during the cars lifetime anyway.

[Kleinstein]

The THTR pebble bed reactor had troubles with the ball not sliding / moving as expected. So they god jammed and broken fuel balls. AFAIK the problems where due to the size and thus higher forces and the graphite / silicon-carbide surfaces behaving different in the clean helium atmosphere. They did not had the problems in the smaller test reactor build before and AFAIK all other pebble bed reactors where also smaller. Size a problem anyway, as the pressure vessel and needed containment as a backup gets difficult to build. This alone makes it a cost problem.

The THTR also had a relatively serious incident, that damaged the pressure vessel - so essentially damaging the reactor beyond repair. The accident happened just a few days after the Chernobyl disaster and thus did not get the normal attention.  In addition they could not get more of the special fuel, the breeding rate was lower than hoped for and the reprocessing turn out to be more complicated. So they never really started recycling the fuel. It is not only the thorium fuel but also the carbon balls that makes recycling difficult.

The problem with helium cooling is that once there is a leak in the helium flow, its difficult to add spare coolant. Nitrogen is less efficient. Without enough cooling a 2000 C stability would not help as the temperature could rise even further if things go wrong. There is no magic stop at 2000 C, especially for a large reactor. With a few broken fuel balls there could be hot spots developing.

I don't think spare batteries for EV are that attractive. In theory this may work, in a kind of swapping system as was already planed before fast charging got chosen. Swapping batteries would than be the alternative to waiting for a charge - this could be central and with batteries on lease. So no more second battery for every EV and batteries not owned with the EV but to a central service organization. At least for something like electric buses this could be a good system.

[apis]

It was my impression that the 2000 C is a "magic" stop if you loose coolant, due to thermal broadening of the neutron spectrum. It would have to be 4000 C to be a danger to the carbide? That is why they are considered passively safe.

"There was a pebble bed reactor accident at Hamm-Uentrop West Germany nine days after the Chernobyl accident. On May 4 1986, a pebble became lodged in a feeder tube. Operators subsequently caused damage to the fuel during attempts to free the pebble. The West German government closed down the research program because they found the reactor design unsafe." Sounds like they shut it down due to panic after the Chernobyl accident. The problem doesn't sound like it has to do with the reactor design in general but rather that that specific reactor had under dimensioned feeder tubes.

I don't really understand why people don't like the battery swap solution, wouldn't prevent people from charging at home at the same time. The key social benefit would be that you can charge batteries during peak production. For the individual the benefit is that you can fill up the tank in a few minutes compared to the 20 or so hours you need for a full charge now (which means you solve the range problem). You also spread out the cost of a new battery so that people doesn't have to save up for a large investment in a new battery.

[nctnico]

The problem with battery swapping is that it isn't a matter of pulling a pack out but dealing with a brick which is around 500kg. Making the battery swappable in an easy way probably has a severe impact on how the (self supporting) body of the car has to be designed an fabricated. There is a lot more to swapping batteries than you'd think.

[apis]

Of course, you wouldn't do it by hand and there would have to be some standardisation of the batteries.

[Kilrah]

Assuming you can wear out both batteries during the lifetime of the car the overall cost isn't higher. I.e. if you have to replace the battery once during the cars lifetime anyway.

But you can't. Batteries degrade with age and not just cycles, so getting 2 batteries at the start won't give you anywhere near twice the lifetime of one, and it falls apart.

You might be able to do 10 years with 2 batteries (aka replacing the first one after 5, doing 5 more with the 2nd) but if you buy 2 on day one they'll both be dead after 6 years so you're not getting the value back.

[Mr. Scram]

But you can't. Batteries degrade with age and not just cycles, so getting 2 batteries at the start won't give you anywhere near twice the lifetime of one, and it falls apart.

You might be able to do 10 years with 2 batteries (aka replacing the first one after 5, doing 5 more with the 2nd) but if you buy 2 on day one they'll both be dead after 6 years so you're not getting the value back.

I'm not sure batteries degrade that quickly over time. Can you support this?

[Kilrah]

We have long since abandoned any hope of energy independence

Yeah but it still stays within a pretty close geographical proximity, where "friendships" are easier to maintain... yet a "follow-the-sun grid" needs wide east-west geographical separation. And mentalities seem to make it harder to keep things in control on this axis than on the north-south one unfortunately...

There's recently been a mess about Russian gas supply to Europe...

If you just produce solar in Sahara, for example, and export that north to Europe, Europe wouldn't need coal during the day: voilà, coal is reduced by nearly 50%.

Examples of some underwater power cables
Baltic cable: 250 kilometres with a maximum transmission power of 600 megawatts
Basslink: 370 km 500 MW

Sahara to "North of Europe" is 10 times that distance. You'll lose so much as to make the whole point moot. Not to mention that bringing 600MW up there would be negligible.

My country is half the way, small, and from the numbers I can Google needs about 17TW. So your 600MW cable only covers a negligible 3.5%, and it runs 250km instead of the 1500 required.

Covering a minimally significant portion (say 10%?) of that geographical region would need would probably involve carrying 1000TW over an average of 1500km or so...

[Kilrah]

I'm not sure batteries degrade that quickly over time. Can you support this?

Been using various types of lithium batteries over 15 years now, some with regular use and some with most of their time spent on a shelf at storage level, and yes I sure can. Unless you put a REALLY low load on them after 5 years or so they're just done. Capacity may still be somewhat OK, but IR shoots up making them useless for most applications.

[Mr. Scram]

Been using various types of lithium batteries over 15 years now, some with regular use and some with most of their time spent on a shelf at storage level, and yes I sure can. Unless you put a REALLY low load on them after 5 years or so they're just done. Capacity may still be somewhat OK, but IR shoots up making them useless for most applications.

Did you do any controlled testing? I have to admit I was after actual research, not personal anecdotal evidence.

[Mr. Scram]

Yeah but it still stays within a pretty close geographical proximity, where "friendships" are easier to maintain... yet a "follow-the-sun grid" needs wide east-west geographical separation. And mentalities seem to make it harder to keep things in control on this axis than on the north-south one unfortunately...

There's recently been a mess about Russian gas supply to Europe...

Sahara to "North of Europe" is 10 times that distance. You'll lose so much as to make the whole point moot. Not to mention that bringing 600MW up there would be negligible.

My country is half the way, small, and from the numbers I can Google needs about 17TW. So your 600MW cable only covers a negligible 3.5%, and it runs 250km instead of the 1500 required.

Covering a minimally significant portion (say 10%?) of that geographical region would need would probably involve carrying 1000TW over an average of 1500km or so...

Doing long distance power transmission probably requires more modern solutions. There are various examples of superconductors being used for real world power transmission applications.

[Kilrah]

Not controlled and repeateable, good luck finding that, not many people will store a bunch of batteries for a decade with regular scientific level evaluation and post the results.
But I've taken "new" cells that had never seen a single cycle but sat 7 years in a drawer, used them to rebuild a laptop battery, and got a third of the expected runtime. Good luck finding an 8 year old laptop with more than a few minutes of battery life - whether it was used a lot or not. Got some used collectibles that were visibly barely used, but the battery was dead anyway.

Pretty consistent with several other RC model batteries I've had laying around. Take what you want out of it.

[Kilrah]

There are various examples of superconductors being used for real world power transmission applications.

I ceertainly would be excited to see a 1500km superconductor run!

[nctnico]

My country is half the way, small, and from the numbers I can Google needs about 17TW. So your 600MW cable only covers a negligible 3.5%, and it runs 250km instead of the 1500 required.

That can't be right. You are probably mistaken the annual use in TWh. Germany has about 200GW of generating capacity but half of that is wind + solar so let's say 100GW is enough for when there is no sun and wind. Austria is likely to need much less. I estimate Europe could be powered with 2 to 3TW of generating capacity. Still getting that kind of power across the mediteranian sea will be a huge technical challenge.

[Mr. Scram]

Not controlled and repeateable, good luck finding that, not many people will store a bunch of batteries for a decade with regular scientific level evaluation and post the results.
But I've taken "new" cells that had never seen a single cycle but sat 7 years in a drawer, used them to rebuild a laptop battery, and got a third of the expected runtime. Good luck finding an 8 year old laptop with more than a few minutes of battery life - whether it was used a lot or not. Got some used collectibles that were visibly barely used, but the battery was dead anyway.

Pretty consistent with several other RC model batteries I've had laying around. Take what you want out of it.

I'm asking because it contradicts my own personal observations, which is one of the reasons I value personal anecdotal evidence little. It seems safe to assume the battery industry or an entity depending on that industry does these kinds of testing in a controlled manner. I've seen well used batteries become essentially useless or completely non-functional, but I've never seen reasonably stored batteries wear out as much without being used and certainly not that much within such a limited timespan.

Doing a little research shows that batteries do deteriorate when stored at elevated temperatures and while charged near capacity. I haven't found any actual numbers on how much after how long, or how this related to lower temperature and lower charge storage. Manufacturers do provide "best before" dates, but these don't appear to be very accurate as they ignore the conditions.

[nctnico]

The problem is that there is no golden rule here. It depends on manufacturer and cell type. This information is only available under an NDA. However Toyota and Tesla have shown that with the right care a Li-ion cell can last very long.

[Kilrah]

That can't be right. You are probably mistaken the annual use in TWh. Germany has about 200GW of generating capacity but half of that is wind + solar so let's say 100GW is enough for when there is no sun and wind. Austria is likely to need much less. I estimate Europe could be powered with 2 to 3TW of generating capacity. Still getting that kind of power across the mediteranian sea will be a huge technical challenge.

Oops, 35.5GW indeed, tired... Rest of your numbers check out. Still a lot...

[Mr. Scram]

The problem is that there is no golden rule here. It depends on manufacturer and cell type. This information is only available under an NDA. However Toyota and Tesla have shown that with the right care a Li-ion cell can last very long.

It doesn't surprise me that the cells in their applications are cooled, which supports the notions that temperature is a significant factor in degradation.

[Kilrah]

I'm asking because it contradicts my own personal observations, which is one of the reasons I value personal anecdotal evidence little. It seems safe to assume the battery industry or an entity depending on that industry does these kinds of testing in a controlled manner. I've seen well used batteries become essentially useless or completely non-functional, but I've never seen reasonably stored batteries wear out as much without being used and certainly not that much within such a limited timespan.ns.

I've also been working with people selling electric propulsion systems for small boats (typically low use), and the manufacturer of the components they distribute warranties their lithium batteries for 8 years... but they've precisely have had a whole lot of hassle to deal with because they all seem to become unsatisfactory after 5 years or so and so they've had a bunch to replace. On their own dime, cause the manufacturer always comes out with some kind of "they must have misused it" to get out of the terms they obviously wrote based on unrealistic expectations back then.

[Marco]

Doing long distance power transmission probably requires more modern solutions. There are various examples of superconductors being used for real world power transmission applications.

The only reason to use superconducting cables is when you are space limited, when you have the room use HVDC.

[Mr. Scram]

I've also been working with people selling electric propulsion systems for small boats (typically low use), and the manufacturer of the components they distribute warranties their lithium batteries for 8 years... but they've precisely have had a whole lot of hassle to deal with because they all seem to become unsatisfactory after 5 years or so and so they've had a bunch to replace. On their own dime, cause the manufacturer always comes out with some kind of "they must have misused it" to get out of the terms they obviously wrote based on unrealistic expectations back then.

I'd expect the same to happen to electrical or hybrid vehicles as they've been around for more than 5 years, but I don't think this generally is the case. Again, I'd love to see some controlled measurements being made on the supposed phenomenon. I'm currently not seeing a lot which suggests two batteries used at the same time will only last marginally longer than one.

[apis]

Assuming you can wear out both batteries during the lifetime of the car the overall cost isn't higher. I.e. if you have to replace the battery once during the cars lifetime anyway.

But you can't. Batteries degrade with age and not just cycles, so getting 2 batteries at the start won't give you anywhere near twice the lifetime of one, and it falls apart.

You might be able to do 10 years with 2 batteries (aka replacing the first one after 5, doing 5 more with the 2nd) but if you buy 2 on day one they'll both be dead after 6 years so you're not getting the value back.

According to research I've seen lithium batteries have a very good shelf-life, but you have to treat them the right way. A lot of electronic equipment doesn't do that, they overcharge them and undercharge them and generally abuse them, either because of ignorance or because what matters is the initial capacity when the item is sold, not the capacity after a few years. In fact it might even be seen as an advantage if the consumer has to buy a new product because the battery failed (but that is another topic). EV batteries are in a different division, EV manufacturers know they need to do whatever they can to make the batteries last. There will be some degradation over time but it will be mostly the number of cycles that matters. Having battery stations like Kleinstein suggested doesn't have this "shelf life problem" though, so we could always go with that instead if you think I'm wrong about this.

We have long since abandoned any hope of energy independence

Yeah but it still stays within a pretty close geographical proximity, where "friendships" are easier to maintain... yet a "follow-the-sun grid" needs wide east-west geographical separation. And mentalities seem to make it harder to keep things in control on this axis than on the north-south one unfortunately...

There's recently been a mess about Russian gas supply to Europe...

If you just produce solar in Sahara, for example, and export that north to Europe, Europe wouldn't need coal during the day: voilà, coal is reduced by nearly 50%.

Examples of some underwater power cables
Baltic cable: 250 kilometres with a maximum transmission power of 600 megawatts
Basslink: 370 km 500 MW

Sahara to "North of Europe" is 10 times that distance. You'll lose so much as to make the whole point moot. Not to mention that bringing 600MW up there would be negligible.

My country is half the way, small, and from the numbers I can Google needs about 17TW. So your 600MW cable only covers a negligible 3.5%, and it runs 250km instead of the 1500 required.

Covering a minimally significant portion (say 10%?) of that geographical region would need would probably involve carrying 1000TW over an average of 1500km or so...

As I wrote before; I believe we need everything we got that can replace fossil fuels, including more nuclear, and we are probably still going to have to reduce power consumption. It's technically doable but the big question is if it is politically doable.

I don't believe solar and wind can replace everything over night (that is why I keep saying nuclear power is necessary) and I wasn't claiming we should try to replace all electricity in Europe with solar from Sahara. The point I was trying to make was that even without storage solar (and wind) can reduce GhG emissions significantly. It doesn't have to be produced in Sahara, but I believe some of it could. (Even that would be difficult for political reasons, but probably less of a problem than importing Russian gas.) Scandinavia doesn't really need to import any extra power, we are doing fine with hydro and nuclear. We need more nuclear though, which is why Finland is building more now (probably not enough though). The cables I mentioned are examples of under sea cables. One of them is from Sweden to Germany. Such cables can take care of the Mediterranean. Sweden and Norway actually export a lot of hydro south, that hydro is mainly produced in the far north more than 1000 km away, and it is said by those in the industry that the transmission losses are not a bottleneck. You wouldn't have to replace all power in Europe with solar from Sahara of course, to begin with only about 50% of the energy in Europe comes from fossil fuels. Saharan sunlight would just be one of many contributions and every percent that can replace fossil fuel would help.

[apis]

Doing long distance power transmission probably requires more modern solutions. There are various examples of superconductors being used for real world power transmission applications.

That sounds interesting, I wonder what the cost and maximum capacity of a superconducting under sea cable could be!