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I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme. This is shortsighted because (1) for electricity renewables ar

I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme. This is shortsighted because (1) for electricity renewables are cheaper than nuclear, and (2) large naval vessels are enormously vulnerable to drones. Ukraine's success against Russia's Black Sea fleet proves this for surface vessels. Similarly, it is easy to imagine a swarm of small underwater drones detecting, tracking and trailing nuclear submarines. The UK government's is more focussed on providing juicy contracts to large corporations than realistic preparations for the future.

mr_toad 10mo ago
> Similarly, it is easy to imagine a swarm of small underwater drones detecting, tracking and trailing nuclear submarines. Those are called torpedoes.
- Retric 10mo ago
  It’s way cheaper to build a drone that doesn’t need to travel quickly or carry huge amount high explosives.
  - greedo 10mo ago
    How is a slow, lightly armed drone going to damage a nuclear submarine that can both outrun and outdive it?
    - Retric 10mo ago
      The drone’s goal is to locate it, you’d then send something else to destroy it if you’re in an actual war. America uses surface buoy’s to similar effect, going underwater would allow drones to be harder to detect. https://idstch.com/military/navy/navy-researching-new-buoy-technologies-naval-antisubmarine-warfare/ https://idstch.com/military/navy/navy-researching-new-buoy-t... Of note you don’t necessarily need to be able to track a sub everywhere, an invisible underwater “fence” may be good enough.
      - greedo 10mo ago
        How is a small drone, with limited power and a small sensor suite going to detect the quietest ships in the ocean? And then transmit tracking data? SOSUS is basically gone since the USN hates AWS work (much like the Air Force hates CAS). IUSS never went anywhere as far as I can research (see above why), and really isn't the same as a drone system.
        Retric 10mo ago
        It’s a huge design space. One easy to understand example is a passive sonar underwater drone that stays close enough to the surface to gather sunlight and easily communicate with satellites without also being visible on the surface or making sounds from surface wave action. It can then send high frequency radio signals to satellites which rapidly attenuate through the ocean creating a near perfect stealth system vs subs. The option exists to deploy a string of much deeper sensors via a tether. Another option is close equivalents to the existing systems dropped from aircraft, though with significantly more stealthy deployment. Etc etc.
        greedo 10mo ago
        It's a huge design space but the sea is a harsh mistress. Look at sonobuoys for example; some are passive, just using a hydrophone and relaying any signals via UHF/VHF and others are active where they ping and then relay signals. Generally, they're good for about eight hours. And they have no propulsion system, they just float. Now you want to add a solar array (without being visible). And easily communicating with satellites will rapidly eat into your power budget, even without worrying about propulsion. Yes, sensors can be tethered. We've done that since the early 80's, and let our SOSUS systems deteriorate since the fall of the USSR. But these aren't drones, aren't anything like a swarm of drones. Let's not shift the goalposts away from the original argument.
        Retric 10mo ago
        > Generally, they're good for about eight hours. That’s a function of how aircraft dropped sonobuoys are used. Subs aren’t going to stay still and the ocean is a big place so long lifespans are pointless. However for harbors you want continuous monitoring and so use a different design. As to talking with satellites, that’s become very efficient at low bandwidth. If your 100W radio is off 98% of the time it doesn’t add up to a lot of energy.
wbl 10mo ago
Ukraine's success proves that you need to actually have people guarding ships against intrusion. This is not a new lesson ever since the Raid on the Medway.
_n_b_ 10mo ago
> I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme It absolutely isn’t. There is very little crossover between the RR SMR (which is 470 MWe, not really an ‘SMR’ by IAEA definition) and a submarine reactor core. Sub cores are smaller and optimised for different conditions. They’re vastly different tech. The teams at RR working on these are totally distinct with no crossover. RR just got £9B for sub NSSS work. They don’t need a back door subsidy when they have a big cheque coming right through the front door! If anything, UK govt is prioritising domestic technology, whether or not that’s the best from a purely economic point of view.
- ViewTrick1002 10mo ago
  It is all about having the workforce able to deliver on the military ambitions. This has been well known for a while, and western governments have started to say the quiet part out loud to justify the insanely large handouts required to build civillian nucleaar power. https://theconversation.com/military-interests-are-pushing-new-nuclear-power-and-the-uk-government-has-finally-admitted-it-216118 https://theconversation.com/military-interests-are-pushing-n...
0x000xca0xfe 10mo ago
Renewables are cheap but storage isn't.
- detritus 10mo ago
  ...just quite yet.
- epistasis 10mo ago
  In 2025 storage is cheap too, it's just that there's no need for it until you already have a large amount of renewables. 2025 is the year that storage is really being deployed in a serious manner in the US, more than 18GW most likely: https://www.eia.gov/todayinenergy/detail.php?id=65964 https://www.eia.gov/todayinenergy/detail.php?id=65964 You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables: https://www.eia.gov/todayinenergy/detail.php?id=64586 https://www.eia.gov/todayinenergy/detail.php?id=64586 And the prevalence of batteries in Texas means that they must be cost effective, because all grid assets in Texas are from private investors risking their own capital, and there is zero incentive for batteries except for their profit generative capacity.
  - Closi 10mo ago
    > You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables: It could be - but the battery investments map also align with the map below which shows that these states (Texas & California) are also states suffering from blackouts. https://worldpopulationreview.com/state-rankings/power-outages-by-state https://worldpopulationreview.com/state-rankings/power-outag... So while this could mean that storage is cheap, it could also mean 'Texas's mix and grid is unstable, particularly as it's not connected to the national grid, and this has opened the opportunity to profit from higher levels battery arbitrage that doesn't exist in a better balanced grid'
    - epistasis 10mo ago
      That looks to be a population map: https://xkcd.com/1138/ https://xkcd.com/1138/ Which is what you would expect of a stat of "number of outages per state". If it's not normalized for land area, population, and all the other primary contributors to the total number of outages it's a useless stat. San Francisco has more people in it that the entire state of Wyoming. Texas' power is also cheap, so to justify batteries they would have to not raise the cost of electricity that much. The current cost of grid batteries is hidden, but it's not too hard to find out, and it is indeed quite cheap. But if there's no mechanism to get paid, ie ability to do time arbitrage in the energy market, then they do not get deployed. Electricity market design and the ability of ISOs/PUCs/utilities to adapt to changing technology are bigger barriers to batteries than their price.
FridayoLeary 10mo ago
As for point one they are much less reliable because they are intermittent. I'm skeptical of how much cheaper renewables are. I haven't noticed energy prices declining recently. Correct me if i'm misinformed. I'm slightly confused by point 2. What are you saying, because soviet technology is getting sunk a lot we should stop bothering with having a navy? Either way you are giving way to much credit to the power of the UK military industrial complex.
- zoul 10mo ago
  Solar power is very cheap and still getting cheaper: https://www.statista.com/chart/35117/levelized-cost-of-energy-generation-by-source/ https://www.statista.com/chart/35117/levelized-cost-of-energ...
  - chickenbig 10mo ago
    Solar power doesn't work well in the UK in winter, with 1/3 of the energy output of summer months. Taking the limit of free solar power, what would the storage requirements look like for the UK?
    - TheOtherHobbes 10mo ago
      The UK is aiming for around 27GW of battery storage by 2030. But it's not a simple picture. The grid needs to be expanded to distribute power from renewables more efficiently, batteries aren't the only storage option, and the concept is still too centralised. A combination of distributed rooftop solar with domestic batteries, maybe local storage in substations, strategic national storage, and a mix of sources would be a more effective strategy than trying to park huge batteries around the country in the hope they'll be big enough. The UK still has a post-war mindset around energy which doesn't make sense in the 21st century.
      - chickenbig 10mo ago
        > The UK is aiming for around 27GW of battery storage by 2030. How many GWh? Citation please.
dan-robertson 10mo ago
The Royal Navy only uses nuclear power for submarines, at least for now (unlike USN which uses it for big aircraft carriers)
- lazzurs 10mo ago
  Making the two new UK aircraft carriers dependent on natural gas has to be one of the worst military procurement decisions of the modern era.
  - 7952 10mo ago
    Its fuelled with diesel, not natural gas. And all carriers need refuel at some point for their embarked aircraft.
    - crote 10mo ago
      Sounds like it is time to dust off those nuclear-powered airplane blueprints from the 60s!
      - 7952 10mo ago
        The USN have a research project around using electricity to produce synthetic fuel from sea water.
  - dan-robertson 10mo ago
    In World War II, it was in hindsight a poor decision for the Royal Navy to stick with coal and an expectation of nearby friendly ports to refuel. The USN having oil-burning ships that could be more easily refuelled at sea meant an increased range and this made a difference in the pacific with most formerly friendly ports in the hands of the enemy. The Royal Navy may have been less happy with oil than coal due to not having a source on the British mainland. Today, it seems unlikely that a Royal Navy aircraft carrier will be far from friendly ports. More likely for it to be used to launch air attacks against a relatively weak adversary (think of something like the military actions near the Arabian peninsula in the last 50 years or so). There are also Royal Navy oilers and other logistics ships that can replenish fuel or other resources.
throw0101a 10mo ago
> I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme. Ontario, Canada is building a bunch of BWRX-300 SMRs and don't really have a desire for a naval reactor programme: * https://www.cbc.ca/news/canada/toronto/carney-ford-announce-smr-spending-9.6949828 https://www.cbc.ca/news/canada/toronto/carney-ford-announce-... * https://www.opg.com/projects-services/projects/nuclear/smr/darlington-smr/ https://www.opg.com/projects-services/projects/nuclear/smr/d... * https://www.gevernova.com/news/press-releases/ge-vernova-hitachi-ontario-power-generation-build-first-small-modular-reactor-western-world-canada https://www.gevernova.com/news/press-releases/ge-vernova-hit... Canada is currently looking at new submarines, and the final two candidates are both SSKs (and not nuclear SSNs): * https://www.defensenews.com/naval/2025/08/28/canada-shortlists-german-south-korean-yards-for-massive-sub-program/ https://www.defensenews.com/naval/2025/08/28/canada-shortlis... * https://www.canada.ca/en/public-services-procurement/news/2025/08/government-of-canada-advances-to-next-step-in-canadian-patrol-submarine-project-procurement.html https://www.canada.ca/en/public-services-procurement/news/20... As an Ontario resident I wish they chose to build more CANDUs (which, AIUI, they are planning to do as well) rather than SMRs: our grid is in more need of 'bulk power', and SMRs are better suited to small grids (like the Canadian Maritimes) or small sites (like in Poland: replacing previous smaller scale coal plants).
Closi 10mo ago
> This is shortsighted because [...] electricity renewables are cheaper than nuclear This is an oversimplification - Renewables are cheaper than nuclear, but they are also less reliable than nuclear in the sense that when the wind stops blowing, power stops being generated. Also if you include the cost of energy storage to survive a week or two without substantial wind, suddenly it's not the cheaper anymore. A mixed nuclear + renewables grid would reduce the total cost because nuclear can provide a stable base load which isn't affected by seasonality. Modern plants can also ramp up/down to some extent to balance the overall system. That's why you need an energy mix rather than just putting all your eggs in a single source.
- TheOtherHobbes 10mo ago
  If you invest in battery and storage tech you'll get reliable storage long before the first "baseload nukes" start contributing to the grid. Storage tech has been criminally underfunded and under-researched. There are many, many options. But because of poor investment decisions and lobbying from the usual suspects the tech is around twenty years behind where it could be.
  - jayflux 10mo ago
    That’s simply not true, or at least not today. First of, the UK are investing in battery storage, there’s already a rollout of grid-level battery systems across the country*. None of them hold capacity for longer than 2 hours before they need to start discharging. In fact, the record breaking duration is 6 hours. This is great as a short buffer, but it’s not “storage”. To put this in perspective, last year the UK went 2 weeks without any significant wind, so a 2 hour buffer is nothing. This is why Hydrogen is still being kept as an option for long term storage. https://stateraenergy.co.uk/projects/thurrock-storage https://stateraenergy.co.uk/projects/thurrock-storage https://rhomotion.com/news/longest-duration-battery-energy-storage-project-in-the-uk-gets-the-go-ahead/ https://rhomotion.com/news/longest-duration-battery-energy-s...
    - ViewTrick1002 10mo ago
      The ratio between GW and GWh is always an optimization of the fixed costs vs potential profit. A 4 hour battery can run at 50% for 8 hours or 25% for 16 hours. The determining factor is what the market needs.
ReptileMan 10mo ago
Russia's naval prowess have always been a joke so you can't make too many conclusions.
greedo 10mo ago
It's dangerous to extrapolate much from the performance of the Russian Navy in the Black Sea. While Ukraine has had remarkable success in almost completely shutting down Russian naval activity in the Black Sea, it's not all due to the superiority of drones. Russian incompetence, both in naval strategy as well as operations is endemic, and the fate of the Moskva and other systems isn't indicative of a widespread vulnerability of surface vessels to drone systems. The Moskva was sunk with cruise missiles, primarily ones developed from Soviet era missiles (Kh-35). Much has been written about the materiel state of the Moskva, as well as operational decisions/inadequacies that lead to its demise. Surface drones work well when air cover is limited/restricted. Tracking them via radar is difficult due to surface noise, but it can be done. Countering them isn't an impossible task either, it, like other threats are handled systematically. The Russians have a relatively slow OODA loop, and Ukraine has been very successful in leveraging their superiority. Is the threat a universal one or limited to the UKR/Russian conflict? A little of both. We've seen where an unprepared ship can be easily damaged by a small boat laden with explosives (USS Cole). We've seen the Ukrainians shut down Russian activity in the Black Sea, even going so far as to down unwitting aircraft that didn't respect the threat. But militaries adapt, especially to proven threats. Witness how the West responded to the sinking of the Eilat in 1973. It developed countermeasures and weapon systems for the threat of cruise missiles, while simultaneously developing their own cruise missiles (Harpoon/Exocet/Otomat/Penguin). Will undersea drones prove as concerning? I doubt small swarms of UUVs will proliferate like we've seen with FPV drones. Flying through the air is much much easier than operating in water. Propulsion, C2, and targeting is quite difficult underwater compared to UAVs. Both range and payload are a challenge, so I don't believe that a swarm of "small underwater drones" will be able to detect the quietest ships in the ocean any time soon, much less track and trail something that can travel at speeds above 40kts with ease. Now will large UUVs have a role in future naval combat? Undoubtedly.
Melatonic 10mo ago
It would also provide a steady source of tritium for upkeeping nuclear weapons
- DoctorOetker 10mo ago
  This: nuclear energy is a subsidy for nuclear weapons.
OJFord 10mo ago
> electricity renewables are cheaper than nuclear Are they still if you include storage, vs. nuclear's continuous generation?
- hdgvhicv 10mo ago
  Continue generation is great if you have continues demand. The U.K. does not have that (especially if you include heating and travel which is currently mainly provided by gas)
  - jayflux 10mo ago
    That’s quite an odd statement to make. The UK certainly does have continuous demand, our overall energy demand has rarely fallen below 25GW in the past couple of years. Right now gas makes up for much of that, the goal here is to replace gas with nuclear, using gas as baseload generation isn’t wise long term. Source: https://grid.iamkate.com/ https://grid.iamkate.com/
    - hdgvhicv 10mo ago
      Our demand varies from 25 to 45GW Saying “nuclear can handle the easy part” doesn’t help. You still need 20GW of extra capacity to cope. It’s like saying “wind can handle the bulk of the capacity you just need to top up the rest”.
      - jayflux 10mo ago
        I’m sorry I struggle to understand your comment, but I’ll have a go. > Saying “nuclear can handle the easy part” doesn’t help. That’s literally how baseload works, look at France’s energy mix for an example, they have nuclear handle the bulk of their demand (at least the very minimum it will ever be) and renewables + transfers handle the rest, if renewables goes up they export it or lower their nuclear output (yes, their nuclear output can be modulated). > You still need 20GW of extra capacity to cope The goal isn’t to replace the entire energy mix with Nuclear, the goal is to add enough nuclear in the mix so that we don’t need gas being generating all year round (gas sets the price in the merit order so we don’t want it on 24/7). If you added just 6GW of nuclear you’d be achieving that on some days.
AnonymousPlanet 10mo ago
People often underestimate the amount of storage you need for renewables. Depending on the geographic location you might be looking at tens of TWh. The cost for renewables then suddenly becomes much higher. I recommend everyone who is using the cost argument to actually do the math on this first. It might be an eye opening experience. It certainly was for me.
- mqus 10mo ago
  Could you share your numbers as well? According to [1], the UK currently needs about 300TWh per year. Lets say we go entirely solar+wind+battery(whatever that means) and assume that battery has to bridge a gap of at most 7 days (meaning no wind and no solar at all during this time, which is at most a few days at a time). This adds up to 300/365*7= 5,8TWh of max capacity. Lets take it safe, round up and say we need 10TWh (which is already not "tens of TWH", but "ten"). [2] Says that grid-scale batteries come at around 350$ per kWh right now. kWh -> TWh is factor 1 billion (10^9), meaning if we want to build 10TWh of storage, it will cost 3,5 Trillion Dollars. Impressive number indeed. But there are multiple asterisks here. 1. This calculation takes into account that there is no exchange with mainland europe and no gas power plants or other sources of power (e.g. hydro or hydro storage). This sharply reduces the need for batteries. 2. Battery costs will fall in the next decades, compared to nuclear, which will take a long time (if ever) until costs will fall. [1] https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu... [2] https://docs.nrel.gov/docs/fy25osti/93281.pdf https://docs.nrel.gov/docs/fy25osti/93281.pdf
- osn9363739 10mo ago
  Can you share the math?
- crote 10mo ago
  The problem is that the math is often done using faulty assumptions, such as expecting to rely solely on batteries to store enough energy to last several months. In practice there are never long periods with and zero wind and zero solar and zero import capacity. Place the right price on electricity during peak demand, and suddenly the market is more than happy to install an overcapacity of wind & solar. Gigawatt-capacity cables to neighboring countries? Already being built! A country like the UK needs an average electricity input of 45GW. It is totally fine to serve that with 60GW of wind operating at 25% capacity, 60GW of solar operating at 25% capacity, and 15GW of import operating at 100% capacity.

mr_toad 10mo ago

> Similarly, it is easy to imagine a swarm of small underwater drones detecting, tracking and trailing nuclear submarines. Those are called torpedoes.

Retric 10mo ago
It’s way cheaper to build a drone that doesn’t need to travel quickly or carry huge amount high explosives.
- greedo 10mo ago
  How is a slow, lightly armed drone going to damage a nuclear submarine that can both outrun and outdive it?
  - Retric 10mo ago
    The drone’s goal is to locate it, you’d then send something else to destroy it if you’re in an actual war. America uses surface buoy’s to similar effect, going underwater would allow drones to be harder to detect. https://idstch.com/military/navy/navy-researching-new-buoy-technologies-naval-antisubmarine-warfare/ https://idstch.com/military/navy/navy-researching-new-buoy-t... Of note you don’t necessarily need to be able to track a sub everywhere, an invisible underwater “fence” may be good enough.
    - greedo 10mo ago
      How is a small drone, with limited power and a small sensor suite going to detect the quietest ships in the ocean? And then transmit tracking data? SOSUS is basically gone since the USN hates AWS work (much like the Air Force hates CAS). IUSS never went anywhere as far as I can research (see above why), and really isn't the same as a drone system.
      - Retric 10mo ago
        It’s a huge design space. One easy to understand example is a passive sonar underwater drone that stays close enough to the surface to gather sunlight and easily communicate with satellites without also being visible on the surface or making sounds from surface wave action. It can then send high frequency radio signals to satellites which rapidly attenuate through the ocean creating a near perfect stealth system vs subs. The option exists to deploy a string of much deeper sensors via a tether. Another option is close equivalents to the existing systems dropped from aircraft, though with significantly more stealthy deployment. Etc etc.
        greedo 10mo ago
        It's a huge design space but the sea is a harsh mistress. Look at sonobuoys for example; some are passive, just using a hydrophone and relaying any signals via UHF/VHF and others are active where they ping and then relay signals. Generally, they're good for about eight hours. And they have no propulsion system, they just float. Now you want to add a solar array (without being visible). And easily communicating with satellites will rapidly eat into your power budget, even without worrying about propulsion. Yes, sensors can be tethered. We've done that since the early 80's, and let our SOSUS systems deteriorate since the fall of the USSR. But these aren't drones, aren't anything like a swarm of drones. Let's not shift the goalposts away from the original argument.
        Retric 10mo ago
        > Generally, they're good for about eight hours. That’s a function of how aircraft dropped sonobuoys are used. Subs aren’t going to stay still and the ocean is a big place so long lifespans are pointless. However for harbors you want continuous monitoring and so use a different design. As to talking with satellites, that’s become very efficient at low bandwidth. If your 100W radio is off 98% of the time it doesn’t add up to a lot of energy.

wbl 10mo ago

Ukraine's success proves that you need to actually have people guarding ships against intrusion. This is not a new lesson ever since the Raid on the Medway.

_n_b_ 10mo ago

> I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme It absolutely isn’t. There is very little crossover between the RR SMR (which is 470 MWe, not really an ‘SMR’ by IAEA definition) and a submarine reactor core. Sub cores are smaller and optimised for different conditions. They’re vastly different tech. The teams at RR working on these are totally distinct with no crossover. RR just got £9B for sub NSSS work. They don’t need a back door subsidy when they have a big cheque coming right through the front door! If anything, UK govt is prioritising domestic technology, whether or not that’s the best from a purely economic point of view.

ViewTrick1002 10mo ago
It is all about having the workforce able to deliver on the military ambitions. This has been well known for a while, and western governments have started to say the quiet part out loud to justify the insanely large handouts required to build civillian nucleaar power. https://theconversation.com/military-interests-are-pushing-new-nuclear-power-and-the-uk-government-has-finally-admitted-it-216118 https://theconversation.com/military-interests-are-pushing-n...

0x000xca0xfe 10mo ago

Renewables are cheap but storage isn't.

detritus 10mo ago
...just quite yet.
epistasis 10mo ago
In 2025 storage is cheap too, it's just that there's no need for it until you already have a large amount of renewables. 2025 is the year that storage is really being deployed in a serious manner in the US, more than 18GW most likely: https://www.eia.gov/todayinenergy/detail.php?id=65964 https://www.eia.gov/todayinenergy/detail.php?id=65964 You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables: https://www.eia.gov/todayinenergy/detail.php?id=64586 https://www.eia.gov/todayinenergy/detail.php?id=64586 And the prevalence of batteries in Texas means that they must be cost effective, because all grid assets in Texas are from private investors risking their own capital, and there is zero incentive for batteries except for their profit generative capacity.
- Closi 10mo ago
  > You can see on the map at the bottom of this page that almost all the batteries are in areas that already have high amounts of renewables: It could be - but the battery investments map also align with the map below which shows that these states (Texas & California) are also states suffering from blackouts. https://worldpopulationreview.com/state-rankings/power-outages-by-state https://worldpopulationreview.com/state-rankings/power-outag... So while this could mean that storage is cheap, it could also mean 'Texas's mix and grid is unstable, particularly as it's not connected to the national grid, and this has opened the opportunity to profit from higher levels battery arbitrage that doesn't exist in a better balanced grid'
  - epistasis 10mo ago
    That looks to be a population map: https://xkcd.com/1138/ https://xkcd.com/1138/ Which is what you would expect of a stat of "number of outages per state". If it's not normalized for land area, population, and all the other primary contributors to the total number of outages it's a useless stat. San Francisco has more people in it that the entire state of Wyoming. Texas' power is also cheap, so to justify batteries they would have to not raise the cost of electricity that much. The current cost of grid batteries is hidden, but it's not too hard to find out, and it is indeed quite cheap. But if there's no mechanism to get paid, ie ability to do time arbitrage in the energy market, then they do not get deployed. Electricity market design and the ability of ISOs/PUCs/utilities to adapt to changing technology are bigger barriers to batteries than their price.

FridayoLeary 10mo ago

As for point one they are much less reliable because they are intermittent. I'm skeptical of how much cheaper renewables are. I haven't noticed energy prices declining recently. Correct me if i'm misinformed. I'm slightly confused by point 2. What are you saying, because soviet technology is getting sunk a lot we should stop bothering with having a navy? Either way you are giving way to much credit to the power of the UK military industrial complex.

zoul 10mo ago
Solar power is very cheap and still getting cheaper: https://www.statista.com/chart/35117/levelized-cost-of-energy-generation-by-source/ https://www.statista.com/chart/35117/levelized-cost-of-energ...
- chickenbig 10mo ago
  Solar power doesn't work well in the UK in winter, with 1/3 of the energy output of summer months. Taking the limit of free solar power, what would the storage requirements look like for the UK?
  - TheOtherHobbes 10mo ago
    The UK is aiming for around 27GW of battery storage by 2030. But it's not a simple picture. The grid needs to be expanded to distribute power from renewables more efficiently, batteries aren't the only storage option, and the concept is still too centralised. A combination of distributed rooftop solar with domestic batteries, maybe local storage in substations, strategic national storage, and a mix of sources would be a more effective strategy than trying to park huge batteries around the country in the hope they'll be big enough. The UK still has a post-war mindset around energy which doesn't make sense in the 21st century.
    - chickenbig 10mo ago
      > The UK is aiming for around 27GW of battery storage by 2030. How many GWh? Citation please.

dan-robertson 10mo ago

The Royal Navy only uses nuclear power for submarines, at least for now (unlike USN which uses it for big aircraft carriers)

lazzurs 10mo ago
Making the two new UK aircraft carriers dependent on natural gas has to be one of the worst military procurement decisions of the modern era.
- 7952 10mo ago
  Its fuelled with diesel, not natural gas. And all carriers need refuel at some point for their embarked aircraft.
  - crote 10mo ago
    Sounds like it is time to dust off those nuclear-powered airplane blueprints from the 60s!
    - 7952 10mo ago
      The USN have a research project around using electricity to produce synthetic fuel from sea water.
- dan-robertson 10mo ago
  In World War II, it was in hindsight a poor decision for the Royal Navy to stick with coal and an expectation of nearby friendly ports to refuel. The USN having oil-burning ships that could be more easily refuelled at sea meant an increased range and this made a difference in the pacific with most formerly friendly ports in the hands of the enemy. The Royal Navy may have been less happy with oil than coal due to not having a source on the British mainland. Today, it seems unlikely that a Royal Navy aircraft carrier will be far from friendly ports. More likely for it to be used to launch air attacks against a relatively weak adversary (think of something like the military actions near the Arabian peninsula in the last 50 years or so). There are also Royal Navy oilers and other logistics ships that can replenish fuel or other resources.

throw0101a 10mo ago

> I suspect that the push for civilian SMRs is a disguised subsidy for the naval reactor programme. Ontario, Canada is building a bunch of BWRX-300 SMRs and don't really have a desire for a naval reactor programme: * https://www.cbc.ca/news/canada/toronto/carney-ford-announce-smr-spending-9.6949828 https://www.cbc.ca/news/canada/toronto/carney-ford-announce-... * https://www.opg.com/projects-services/projects/nuclear/smr/darlington-smr/ https://www.opg.com/projects-services/projects/nuclear/smr/d... * https://www.gevernova.com/news/press-releases/ge-vernova-hitachi-ontario-power-generation-build-first-small-modular-reactor-western-world-canada https://www.gevernova.com/news/press-releases/ge-vernova-hit... Canada is currently looking at new submarines, and the final two candidates are both SSKs (and not nuclear SSNs): * https://www.defensenews.com/naval/2025/08/28/canada-shortlists-german-south-korean-yards-for-massive-sub-program/ https://www.defensenews.com/naval/2025/08/28/canada-shortlis... * https://www.canada.ca/en/public-services-procurement/news/2025/08/government-of-canada-advances-to-next-step-in-canadian-patrol-submarine-project-procurement.html https://www.canada.ca/en/public-services-procurement/news/20... As an Ontario resident I wish they chose to build more CANDUs (which, AIUI, they are planning to do as well) rather than SMRs: our grid is in more need of 'bulk power', and SMRs are better suited to small grids (like the Canadian Maritimes) or small sites (like in Poland: replacing previous smaller scale coal plants).

Closi 10mo ago

> This is shortsighted because [...] electricity renewables are cheaper than nuclear This is an oversimplification - Renewables are cheaper than nuclear, but they are also less reliable than nuclear in the sense that when the wind stops blowing, power stops being generated. Also if you include the cost of energy storage to survive a week or two without substantial wind, suddenly it's not the cheaper anymore. A mixed nuclear + renewables grid would reduce the total cost because nuclear can provide a stable base load which isn't affected by seasonality. Modern plants can also ramp up/down to some extent to balance the overall system. That's why you need an energy mix rather than just putting all your eggs in a single source.

TheOtherHobbes 10mo ago
If you invest in battery and storage tech you'll get reliable storage long before the first "baseload nukes" start contributing to the grid. Storage tech has been criminally underfunded and under-researched. There are many, many options. But because of poor investment decisions and lobbying from the usual suspects the tech is around twenty years behind where it could be.
- jayflux 10mo ago
  That’s simply not true, or at least not today. First of, the UK are investing in battery storage, there’s already a rollout of grid-level battery systems across the country*. None of them hold capacity for longer than 2 hours before they need to start discharging. In fact, the record breaking duration is 6 hours. This is great as a short buffer, but it’s not “storage”. To put this in perspective, last year the UK went 2 weeks without any significant wind, so a 2 hour buffer is nothing. This is why Hydrogen is still being kept as an option for long term storage. https://stateraenergy.co.uk/projects/thurrock-storage https://stateraenergy.co.uk/projects/thurrock-storage https://rhomotion.com/news/longest-duration-battery-energy-storage-project-in-the-uk-gets-the-go-ahead/ https://rhomotion.com/news/longest-duration-battery-energy-s...
  - ViewTrick1002 10mo ago
    The ratio between GW and GWh is always an optimization of the fixed costs vs potential profit. A 4 hour battery can run at 50% for 8 hours or 25% for 16 hours. The determining factor is what the market needs.

ReptileMan 10mo ago

Russia's naval prowess have always been a joke so you can't make too many conclusions.

greedo 10mo ago

It's dangerous to extrapolate much from the performance of the Russian Navy in the Black Sea. While Ukraine has had remarkable success in almost completely shutting down Russian naval activity in the Black Sea, it's not all due to the superiority of drones. Russian incompetence, both in naval strategy as well as operations is endemic, and the fate of the Moskva and other systems isn't indicative of a widespread vulnerability of surface vessels to drone systems. The Moskva was sunk with cruise missiles, primarily ones developed from Soviet era missiles (Kh-35). Much has been written about the materiel state of the Moskva, as well as operational decisions/inadequacies that lead to its demise. Surface drones work well when air cover is limited/restricted. Tracking them via radar is difficult due to surface noise, but it can be done. Countering them isn't an impossible task either, it, like other threats are handled systematically. The Russians have a relatively slow OODA loop, and Ukraine has been very successful in leveraging their superiority. Is the threat a universal one or limited to the UKR/Russian conflict? A little of both. We've seen where an unprepared ship can be easily damaged by a small boat laden with explosives (USS Cole). We've seen the Ukrainians shut down Russian activity in the Black Sea, even going so far as to down unwitting aircraft that didn't respect the threat. But militaries adapt, especially to proven threats. Witness how the West responded to the sinking of the Eilat in 1973. It developed countermeasures and weapon systems for the threat of cruise missiles, while simultaneously developing their own cruise missiles (Harpoon/Exocet/Otomat/Penguin). Will undersea drones prove as concerning? I doubt small swarms of UUVs will proliferate like we've seen with FPV drones. Flying through the air is much much easier than operating in water. Propulsion, C2, and targeting is quite difficult underwater compared to UAVs. Both range and payload are a challenge, so I don't believe that a swarm of "small underwater drones" will be able to detect the quietest ships in the ocean any time soon, much less track and trail something that can travel at speeds above 40kts with ease. Now will large UUVs have a role in future naval combat? Undoubtedly.

Melatonic 10mo ago

It would also provide a steady source of tritium for upkeeping nuclear weapons

DoctorOetker 10mo ago
This: nuclear energy is a subsidy for nuclear weapons.

OJFord 10mo ago

> electricity renewables are cheaper than nuclear Are they still if you include storage, vs. nuclear's continuous generation?

hdgvhicv 10mo ago
Continue generation is great if you have continues demand. The U.K. does not have that (especially if you include heating and travel which is currently mainly provided by gas)
- jayflux 10mo ago
  That’s quite an odd statement to make. The UK certainly does have continuous demand, our overall energy demand has rarely fallen below 25GW in the past couple of years. Right now gas makes up for much of that, the goal here is to replace gas with nuclear, using gas as baseload generation isn’t wise long term. Source: https://grid.iamkate.com/ https://grid.iamkate.com/
  - hdgvhicv 10mo ago
    Our demand varies from 25 to 45GW Saying “nuclear can handle the easy part” doesn’t help. You still need 20GW of extra capacity to cope. It’s like saying “wind can handle the bulk of the capacity you just need to top up the rest”.
    - jayflux 10mo ago
      I’m sorry I struggle to understand your comment, but I’ll have a go. > Saying “nuclear can handle the easy part” doesn’t help. That’s literally how baseload works, look at France’s energy mix for an example, they have nuclear handle the bulk of their demand (at least the very minimum it will ever be) and renewables + transfers handle the rest, if renewables goes up they export it or lower their nuclear output (yes, their nuclear output can be modulated). > You still need 20GW of extra capacity to cope The goal isn’t to replace the entire energy mix with Nuclear, the goal is to add enough nuclear in the mix so that we don’t need gas being generating all year round (gas sets the price in the merit order so we don’t want it on 24/7). If you added just 6GW of nuclear you’d be achieving that on some days.

AnonymousPlanet 10mo ago

People often underestimate the amount of storage you need for renewables. Depending on the geographic location you might be looking at tens of TWh. The cost for renewables then suddenly becomes much higher. I recommend everyone who is using the cost argument to actually do the math on this first. It might be an eye opening experience. It certainly was for me.

mqus 10mo ago
Could you share your numbers as well? According to [1], the UK currently needs about 300TWh per year. Lets say we go entirely solar+wind+battery(whatever that means) and assume that battery has to bridge a gap of at most 7 days (meaning no wind and no solar at all during this time, which is at most a few days at a time). This adds up to 300/365*7= 5,8TWh of max capacity. Lets take it safe, round up and say we need 10TWh (which is already not "tens of TWH", but "ten"). [2] Says that grid-scale batteries come at around 350$ per kWh right now. kWh -> TWh is factor 1 billion (10^9), meaning if we want to build 10TWh of storage, it will cost 3,5 Trillion Dollars. Impressive number indeed. But there are multiple asterisks here. 1. This calculation takes into account that there is no exchange with mainland europe and no gas power plants or other sources of power (e.g. hydro or hydro storage). This sharply reduces the need for batteries. 2. Battery costs will fall in the next decades, compared to nuclear, which will take a long time (if ever) until costs will fall. [1] https://www.statista.com/statistics/322874/electricity-consumption-from-all-electricity-suppliers-in-the-united-kingdom/ https://www.statista.com/statistics/322874/electricity-consu... [2] https://docs.nrel.gov/docs/fy25osti/93281.pdf https://docs.nrel.gov/docs/fy25osti/93281.pdf
osn9363739 10mo ago
Can you share the math?
crote 10mo ago
The problem is that the math is often done using faulty assumptions, such as expecting to rely solely on batteries to store enough energy to last several months. In practice there are never long periods with and zero wind and zero solar and zero import capacity. Place the right price on electricity during peak demand, and suddenly the market is more than happy to install an overcapacity of wind & solar. Gigawatt-capacity cables to neighboring countries? Already being built! A country like the UK needs an average electricity input of 45GW. It is totally fine to serve that with 60GW of wind operating at 25% capacity, 60GW of solar operating at 25% capacity, and 15GW of import operating at 100% capacity.