Subscribe
Notify of
guest
36 Comments
Oldest
Newest
Inline Feedbacks
View all comments
Bloke down the pub

The solution to the power requirements may be available.
Our Technology – Infinite Power (wpengine.com)

stephen ball

Looking forward to more reply’s too your comment.

Joe16

Interesting idea, never come across it before..!
I’m not an expert, but energy is always conserved so the radio isotope would have to be pretty energy dense- meaning radioactive. You’d have to select one of the “lighter” radioactive types to make sure there was no risk to health.
The question then becomes efficiency, and if the radioisotope can emit enough energy for the task. I think current solar panels are something like 25-30% efficient. I guess it just comes down to how densely they can pack the wafers, and how much energy is required. I’d be interested to see how they develop the tech!

Bloke down the pub

They claim a one metre cube cell can produce 10kW. I’d guess that in the context of LUUVs, a combination with lithium batteries would be used in order to smooth peak demand.

Jon

A replacement for a 200 MW reactor in a big sub would be 20,000 cubic metres of Infinite Power battery. Not really scaleable.

The theoretical battery mentioned in the piece with a rating of “5-10 MW hrs of power” doesn’t tell us much even if the battery existed, as MW hrs is not a unit of power but of energy. Without a reasonable idea of power requirements (energy consumed per hour on average) it doesn’t even tell us how often the sub/UUV would need recharging.

Bloke down the pub

Agreed, but we’re talking about XLUUV, not large nuclear subs, so sufficient power to support electronics and keep moving at slow speed is all that is required, not 200mW. The Infinite Power article mentions the lifetime energy of the system because it is aimed at the generation market and needed to give figure for lifetime ROI. Also agree that we can’t guess how useful a couple of 10kW cells would be on an XLUUV without knowing what the power demand is likely to be.

Duker

A nuclear sub reactor is in the 200MW range. But thats ‘thermal power’, most of which goes to waste through the cooling system like any rankine cycle system.

Supportive Bloke

It isn’t a new idea.

Radioactive batteries have been around for decades.

By the time you have something radioactive enough, for the energy density, and screen it properly you have a very, very big lump.

I’m afraid I’d class this a ‘bad idea’.

In the article it mentions ‘bi products’ from the fuel cell. Firstly I assume it means byproducts and secondly there are no byproducts other than pure water from a hydrogen oxygen fuel cell? So I’m lost on that one.

Glass Half Full

Disposing of H2O in the middle of an ocean is hard apparently. 😉

Meirion x

Gamma rays Never get to the surface of the Sun they are blocked and converted to lower energy radiation. Less then 1% of the Sun’s output is X-rays. Some Gamma rays are generated by Solar flares, but are not consistent.
Good job as well, we be fried!!

Last edited 1 month ago by Meirion x
Cam

One huge solar tantrum and we are screwed…

Duker

Like a Carrington Event. It is a bit like a major pandemic from infectious disease, long predicted but a surprise when it did happen.
That last solar one was 1859 and not the electronic world we have today

Cam

Yep, and it’s not if but when, but I’m told we have satellites monitoring the suns solar activity and if a huge even is predicted we can shut off lots of our vital electrical systems to protect them, is that right? And it would still fry loads of our electronics and cause huge problems, what about satellites orbiting earth too?

Duker

Could wreck 90% of cellphone towers electronics, just for starter.
Grid is controlled by digital means now, often they have their own comms system but is it hardened. Same goes for emergency services communications system, they often buy bandwidth from cell phone providers too

Andy a

US grid is split in 3 and isn’t hardened any where near ours. Depends on strength of the event

Bob

I always imagined something similar to this as the “skin” of a spaceship, absorbing cosmic radiation and converting it to power and shielding the occupants.

No idea if it is even possible to design something that will absorb energy at that frequency though.

X

This would add ……… size 

Have you heard how big they say SSN(R) will be?

donald_of_tokyo

Interesting progress. Personal opinion on XLUUV idea;

Long-duration isolated operations, with limited com-link. (Ninja-like tasks)

  • Sneaking into enemy area, locating mines, coming back.
  • Sneaking near enemy port, record the signals (sonar and/or ESM), and bring it back for analysis.
  • Sneaking near enemy port, stay, send alert when some “not normal” activity took place.

Short-duration linked operations, with limited com-link.

  • Work as a “ping” node in multi-static ASW operations. (with pre-programmed ping patterns shared, it can do dozens of ways of pinging with just sending the pattern ID).

Short-duration linked operations, with high-rate com-link (sat-com buoy deployed?)

  • Work as a “listen” node and send the full acoustic data to the ASW multi-static analysis center (T23/26 or even UK). Can also work as a “ping” node. In other words, operate as self-propelled large “sono-buoy”. (Can “control” Irish sea?)

Long-duration linked operations, with high-rate com-link (sat-com buoy deployed?)

  • Work as a “ping” and “listed” node, send the full acoustic data to the ASW multi-static analysis center in UK. Work as a mini-SURTASS ship, but with more assets deployed (say, with 24 units, 12 units always deployed rotating, 4 of them work as “ping” node and the other 8 as “listen” node.)

Some of these tasks do not needed to be an UUV. Actually, most of the ASW tasks can be better done with USV such as iXblue’s Drix USV with TASS, including “with high-rate com-link” tasks.

So, XLUUV will be a Ninja-like asset. (not war-fighting “Holleywood type” Ninja, but sneaking and communication “real Ninja like”).

Cam

Great for recon before amphibious assaults.

donald_of_tokyo

… such energy-dense cells present a major fire risk

Why?

On the propulsion, I am not sure why Li-Ion battery only is a issue with fire? It is surely the same with diesel. In case of fuel cells, it will be even worse. Anyway, it will burn.

On the other hand, there are millions of Li-ion battery based assets operated daily in the world, EV and HV cars. I do not think the battery has higher risk than the fuels? Fuel will burn, those for fuel-cells may even explode, nothing better than batteries, I understand?

Joe16

My understanding is that Li-Ion batteries can be made particularly energy dense, so when/if they catch fire it can be very intense. Google car fires for Teslas (very energy dence Li-Ion batteries) vs petrol vehicles and you’ll see that the damage to the actual structure of the Tesla is far greater than the petrol cars.

Cam

Almost impossible to put out too…

Bloke down the pub

GM advise Chevy Bolt drivers to park their vehicles 50m away from buildings and other vehicles because of the fire risk. It’s not just the risk of fire but the difficulty of putting it out cf fossil fuels that makes operating a large quantity within a mothership problematic. Probably a risk worth taking if the uuv is being operated from shore bases.

donald_of_tokyo

Thanks. My point is, “battery safety” is now the top priority in motor car world. And, “safety in car” is by far the most strict safety requirement these days, much strict than military or space, or even aircraft engineering.

In other words, Li-ion battery safety is an engineering world covered with investment of hundreds of millions of dollars every year. So I think it is solvable issue, not critical. It is very different from many “military specific” (and hence cannot enjoy huge investment) technologies.

Motor car technology is a really really giant world.

Last edited 1 month ago by donald_of_tokyo
Glass Half Full

To which you might add that there are already a number of different Lithium Ion technologies. A XLUUV doesn’t have to use the highest energy density, higher risk technologies, it has the option to use safer solutions and still get the necessary energy storage. For example, at least one Li ion technology has pouch cells that can be cut with scissors or stabbed with a knife, remain stable and don’t start to burn.

Dogs Nads

Worth noting that Sodium Ion and Solid State batteries are rapidly advancing as well…

X

The Japanese have working lithium batteries. And the Koreans are nearly there with a technology from Samsung. But really too dangerous mostly.

D Can

“They are difficult to fight because you can’t put water on the mega packs … all that does is extend the length of time that the fire burns for.”

and

“The recommended process is you cool everything around it so the fire can’t spread and you let it burn out,” Beswicke said.

From https://www.theguardian.com/australia-news/2021/aug/02/tesla-big-battery-fire-in-victoria-burns-into-day-three

This is not ideal on a sub. Australia rejected Li batteries for the Attack class.

donald_of_tokyo

Thanks. But, many of the fuel-cell technology is also very dangerous. I never meant Li-ion battery is safe. No difference to many other “long duration under water technologies”, this is what I wanted to say. For UUVs, we anyway need something to drive them.

Joe16

Great to see the RN getting involved in this tech, although I wish it was progressing a bit quicker…
Not to criticise, but the US and others are already testing and running long duration autonomous underwater vehicles (AUVs) for survey and search tasks- which have an important contribution to ASW among other missions. Some of those systems are the same size as Manta but can autonomously carry out tasks below the waves over a range of over 1,000 km. It is great that we are developing a domestic capabiltiy- I am all for that. We just need to plug more money into it if we’re serious about it being one of the top 3 focusses for the RN…
https://www.sonardyne.com/deep-covert-and-long-range-auvs/

Geoffrey Hicking

The First Sea Lord recently placed the undersea domain in the top 3 priorities for the RN. There is little chance of the manned SSN fleet ever exceeding 7 boats so uncrewed systems are clearly the only realistic way to supplement the all-too-thin ORBAT.

If I’d written that Australia needed SSNs, then I would have had people swarming to say how fantasy-fleet that would be. If I’d said the RN might try and get a next-gen anti-ship missile replacement, then the same might have occurred.

Let’s perhaps hold off on such pronouncements. There is always a chance that clever people used well might find a way to increase SSN numbers even by a small amount when we get to the successor to Astute. Maybe not much of a chance, but I think it is there.

Randy Andy.

Yeah but We is well Woke now like … init…. Long gone is our national focus on real worries.

dick van dyke

It’s a bit like watching my fishing float…… I sit there for ages watching the red and white bit bobbing up and down but nothing much really happens. Hopefully a really good news catch will come along soon !

Cam

Jesus, what size of fish are you trying to catch?

dick van dyke

Well mate…. At My Age, I’m just glad to be able to dangle me tackle truth be known……………………….

Cam

Lol, nice to get it out n the Fresh air too 👍