back to article Boffins build blazing battery bonfire

Energy boffins have proposed an alternative to lithium-ion batteries: Instead of costly electrochemical cells, which have been known to burst into flames, they have devised a "sun in a box" to store energy for power utilities. Imagine a storage tank 10 meters in diameter filled with molten silicon, alongside a few other …

  1. redpawn

    I'm not worried

    about the battery leaking, just all the stuff used to extract the energy.

    1. Mips

      Re: I'm not worried

      Yeah but:

      Thermal system cannot be more than 50% efficient and more like 40% whereas lithium ion systems are going towards 70%.

      How does that factor.

      1. phuzz Silver badge

        Re: I'm not worried

        "Thermal system cannot be more than 50% efficient and more like 40% whereas lithium ion systems are going towards 70%."

        Relevant line from TFA:

        "Lithium-ion costs run about $300 to $400 per kWh-e, he said, while a molten silicon system looks like it can operate at $30 to $40 per kWh-e"

        It's (potentially) ten times cheaper, and that means it can be nine times less efficient and still be worth it.

        1. adam 40 Silver badge

          Re: I'm not worried

          Why compare it to Li-ION batteries though? I thought chemical flow batteries were cheaper and reasonably efficient.

          Also there's now a salt-water electrolyte rechargeable battery which is a cheaper alternative.

        2. Colintd

          Re: I'm not worried

          You're mixing capex with opex. Just because it's much cheaper to build, doesn't mean it will be cheaper to run.

  2. Rich 11

    Interesting idea

    I thought the hot rock idea was already in use, and at considerably less cost per kWh. But maybe the advantage here is in storage capacity per unit volume, especially given the phase change required.

    1. bazza Silver badge

      Re: Interesting idea

      Molten salt is used for this purpose already, have easily handled temperature ranges and being plentiful (near the sea). Silicon heat storage involves much higher temperatures - so harder engineering - but is more efficient as a result.

      Salt has a virtuous benefit; with available energy you can get the salt by desalinating sea water. The salt goes into your heat store, enabling the generation of electricity, and the fresh water is likely a valuable resource in hot, permanently sunny areas suited to solar-salt energy schemes.

      1. Jellied Eel Silver badge

        Re: Interesting idea

        Bah humbug.

        There are no virtuous benefits, just groups looking to extract subsidies. Far from being a 'sun in a box', this is just another example. Plus I'm pretty sure the Sun doesn't fuse silicon.

        So salt's already been used in Spain and California as pseudo-batteries. Problem is the energy losses heating the salt, then converting that heat back into electricity. Which means making a salt-breeder becomes even less efficient given the energy needed for desalination. If you have a hefty power surplus, then it makes more sense.

        Bigger issue is they're usually solutions looking for problems. So solar power. So building and maintaining a large solar power station is expensive. See Ivanpah for more info. $2.2bn for a theoretical 400MW of capacity.. Which it's never achieved, and it'd have been cheaper to use it's gas turbines to generate electricity. That solar plant also uses a LOT of gas. And of course at night, it generates 0MW. Unless it's doing a Spain and spooling up the gas turbines..

        Same for any other solar plant. Power during the day, cost during the night. Subsidy bank snake oil peddlers promise 'solutions'. They'll take expensive power, shrink it due to conversion losses and then sell it on.. Glossing over the implications of all the additional costs involved. Which means no benefit to consumers, because they'll be expected to pay those costs, either directly via energy bills, or indirectly via subsidies.

        There are far cheaper alternatives. So a simple roof-top solar system could store locally using a simple hot water tank and heating element. Cheap, reliable and the operator gets 'free' hot water, give or take solar installation costs. Downside is 'grid scale' battery peddlers don't make money from that, and you can't charge an EV.

        Or if you want to make snake-oil salesman salty, there's always MSR. Standardise and modularise those into say, 1GW or 500MW units and they'll generate power even when it's dark. Or the wind's not blowing.. But that involves the 'N' word, which most Greens hate.. even though it makes far more economic sense, especially if electricity demand keeps growing.

        1. Anonymous Coward
          Alert

          pretty sure the Sun doesn't fuse silicon.

          Not right now...

          1. Anonymous Coward
            Anonymous Coward

            actually never

            Apparently the sun isn't massive enough. Sorry to mislead :(

            1. Jellied Eel Silver badge

              Re: actually never

              Heh, it got me pondering decay chains, so kept me amused for a while :)

            2. Sleep deprived
              Happy

              Re: actually never

              Rest assured that when the Sun engulfes Earth, beach sand will melt.

              1. Anonymous Coward
                Anonymous Coward

                beach sand will melt

                Making fused quartz? I see what you did there. You could say it's... (dons shades) crystal clear.

          2. Mephistro

            Re: pretty sure the Sun doesn't fuse silicon.

            Not by itself, but with sunlight and an image-less solar oven you can fuse about anything.

        2. Anonymous Coward
          Anonymous Coward

          Re: Interesting idea

          Wot he said.

          The fundamental elephants in the room are:

          1/. Is carbon dioxide really affecting climate significantly?

          2/. If it is, is the cost of reducing it greater than dealing with the cost of climate change?

          3/. If it is, zero carbon nuclear power is already cheaper than windmills and solar panels levelised over a decent lifetime and doesn't need very much storage at all - really just enough to cope with diurnal peaks. Seasonal variation is coped for by doing maintenance in summer.

          3/. Adding storage to renewable energy simply adds more cost.

          The question is, therefore, why we haven't simply gone nuclear?

          The answer is of course that governments - and the EU especially - are not actually interested in lowering CO2 emissions. Presumably they know that CO2 does not affect the climate unduly. They are interested in more state interference in energy and subsidies to cronies and that's why we don't have a carbon reduction obligation but a renewable energy obligation.

          Allowing dear old Germany, home of naturism, veganism and that nice animal loving vegan Adolf, to follow it's virtue signalling Energiewende, which whilst pushing renewable energy production (aided by subsidised German windmills of course!) to new highs, has resulted in - despite the fact that Germany STILL has more hydro and nuclear power running than the UK - in the highest CO2 emissions of any country in Europe, per country, per capita and per MWh.

          And that folks, is one of the chief (t)reasons we need to leave the crony club EU.

          When hysterical ideology and emotional narratives replace sober cost benefit analysis, you may well smell a politically and commercially inspired rat.

          1. Jonathan Richards 1
            Thumb Up

            Re: Interesting idea

            > zero carbon nuclear power

            I'm with you a great deal of the way in advocating nuclear solutions to power generation. I thought I'd point out, though, that if one builds a nuclear power station out of concrete (what else?), it isn't zero carbon. A fine Encyclopaedia Anyone Can Edit currently estimates the quantity of CO2 produced for the manufacture of structural concrete (using ~14% cement) at 410 kg/m3. See also the Green Ration Book.

            1. IanRS

              Re: Interesting idea

              This is why wind turbines are not clean too. Big steel tower on a huge concrete foundation = enormous up-front CO2 cost. Apparently they break even after 20 years, out of a 25 year expected usable lifespan.

              1. Alan Brown Silver badge

                Re: Interesting idea

                "Apparently they break even after 20 years"

                Yes. From subsidies. If not spinning.

                If they're running, the big ones have a nasty tendency to eat gearboxes and have their brakes or gearboxes catch fire. It's not so much wind farming as subsidy farming (several large windfarms have been paid about £35k/month/turbine to NOT connect their turbines to the grid - unlike any other form of generation, wind farmers don't have to pay for the lines to connect to the grid or put in storage to prevent South Australia type events, so the grids don't want the costs of their instability)

            2. Cynic_999

              Re: Interesting idea

              "

              I thought I'd point out, though, that if one builds a nuclear power station out of concrete (what else?), it isn't zero carbon.

              "

              Pretty much any form of generating station requires concrete (or equivalent) in its build. A nuclear station may need a bit more than a gas-fired station, but I should think the difference is trivial compared to the saving over the life of the station.

            3. Alan Brown Silver badge

              Re: Interesting idea

              "A fine Encyclopaedia Anyone Can Edit currently estimates the quantity of CO2 produced for the manufacture of structural concrete "

              Almost all of the concrete used in a nuke plant is for the outer steam containment vessel of a conventional light-water-moderated reactor, to be able to handle the stresses involved.

              Get rid of the water and your containment vessel is less than 0.1% fo the size at 1000MW output. 1 litre of water at 400C and 20 atmospheres flashes to ~1500 litres of potentially radioactive steam, amd containing that requires a LOT of concrete structure.

              Because it's so much smaller, the containment building can be much much stronger against improbable things things like having a train driven through it - but because it's not full of highly pressurised radioactive water there's no real benefit for a terrorist in trying that anyway (FlIBe salt freezes solid at 400C, so it won't go far if it leaks and it doesn't dissolve in water so biosphere contamination is unlikely - and unlike liquid sodium it doesn't thave a tendency to catch fire at the slightest leak (Hello Monju!))

              Alvin Weinberg should be one of the first saints of the Technological Age. He invented the nuclear reactor as we know it, wasn't satisfied with the dangerous way it was commercialised so made a much safer one and was tarred&feathered for his trouble.

            4. ivan5

              Re: Interesting idea

              @Jonathan Richards 1

              the same can be said for all the renewable windmills and solar panels. In fact MW for MW renewables produce more CO2 output.

          2. Dr_N
            Trollface

            Re: Interesting idea

            AC> The fundamental elephants in the room are:

            That obvious trolls are obvious?

          3. MacroRodent

            Re: Interesting idea

            1/ : yes. While truth is not determined by majority vote, I find it completely absurd to believe 99.9% of climate researchers have been persuaded to join a global conspiracy promoting a fake climate change problem.

            1. Dr. Mouse

              Re: Interesting idea

              I find it completely absurd to believe 99.9% of climate researchers have been persuaded to join a global conspiracy promoting a fake climate change problem

              While I agree with you, you could use the same reasoning as proof that homeopathy was valid: "I find it completely absurd to believe that 99.9% of homeopathic practitioners have been persuaded to join a global conspiracy...."

              It becomes more likely when you realise that, without climate change, most climate researchers would not have a job (in that field), just as homeopathic practitioners would be out of a job if they admitted they were peddling bovine excrement of the highest order.

              I still, like I said, believe man-made climate change is happening.

              1. Caver_Dave Silver badge
                Boffin

                Re: Interesting idea

                "Homeopathy is placebo. But that doesn't matter. Placebo works even if you know it is placebo!"

                Sources: my wife the Pharmacist who sells people placebo drugs (for a few pence) but she has to remember to ask what they need to cure before giving them out! Plus many double blind trials where the benefits continue after people are told they are on placebos.

                The human mind is truly strange!

              2. MacroRodent

                Re: Interesting idea

                without climate change, most climate researchers would not have a job

                Unlikely. There were climate researchers long before this became a hot item. Hard to say how much it has affected the number of persons working on it, but I doubt it has even doubled or something like that. By contrast, without homeopathy there would be no homeopathists at all. Another difference is that climatology is a science, where evidence makes or breaks theories. Not like pseudosciences, where "researchers" concentrate on confirming the particular fallacy. If global temperatures started falling, and it would continue falling for years, the climatologists would eventually admit they were wrong. But nothing would convince homeopathists that all they see is at best the placebo effect.

                1. Dr. Mouse

                  Re: Interesting idea

                  Another difference is that climatology is a science, where evidence makes or breaks theories. Not like pseudosciences, where "researchers" concentrate on confirming the particular fallacy.

                  I agree. However, I was pointing out the danger of using the "99.9% of X researchers think X is real" argument. It can easily be quashed, especially by those who have a strong disbelief in X, by saying "they are all in it to save their jobs". There are other arguments to be had, this one doesn't really help the cause.

                2. Cynic_999

                  Re: Interesting idea

                  "

                  Another difference is that climatology is a science, where evidence makes or breaks theories.

                  "

                  Really? Such as the evidence that not a single climate model has correctly predicted anything at all, or the evidence that the historical temperature figures were shown to have been altered to support the theories?

                  If what science had predicted 15 years ago had been correct, the chair I'm sitting in would be 5m under water by now.

                  Yes, there is climate change (always has been, always will be). How much man's activities have contributed (if any) is still conjecture rather than science. But in any case it's beside the point. There is no way that Man will change our activities sufficiently to make a gnat's prick worth of difference, so we would be far better off planning how to live with the consequences than coming up with expensive schemes in a vain attempt to prevent the inevitable. And not everything to do with climate change is going to be detrimental by a long chalk - much will be an advantage.

              3. JLV

                Re: Interesting idea

                specious argument.

                no one outside of homeopathists takes their claims seriously.

                yes, climate scientists DO gain employment from climate change concerns.

                but someone who managed to scientically debunk climate change, using good old science - i.e. a sound theory with reproducible results - would immediately achieve scientific superstardom.

                and it’s not like there aren’t tons of people willing to bankroll that line of research. Trump and the US coal industry come to mind.

                Or... there’s always the remote possibility that you are wrong. What level, if any, of proof would it take for you to adapt your worldview to new facts coming to your attention?

              4. Alan Brown Silver badge

                Re: Interesting idea

                "It becomes more likely when you realise that, without climate change, most climate researchers would not have a job "

                The difference is that virtually the entire medical field regard homeopaths as fraudsters, whilst climate researchers have bodies of data, a track record of predictions being accurate and an impressive enough resume to be trusted by the insurance industry - actuaries don't work on "touchy feely" shit, they work on cold hard stats.

                You should also realise that whilst homeopaths are quacks who bilk pateints out of large sums of money, most climate researchers are paid absolutely rotten salaries and _WOULD_ get far better jobs in other sectors(*). They're not in it for the money.

                (*) Disclosure, I work with quite a few as part of my job. The pitiful pay is an issue that causes large staff turnover and they _do_ get good pay in other fields when they've finally had enough of sackcloth and ashes. Unlike the millions spent on politicians for conferences, most climate scientists are lucky to get tea and biscuits, let alone travel expenses covered when they meet.

            2. DuncanLarge Silver badge

              Re: Interesting idea

              Every time I see someone throw the figure 99.9% about like it means anything at all (it doesnt, its a marketing term made popular on antibacterial spays) I wish I could be paid 99.9% of a pound so within 99.9% of my lifetime I may live 99.9% as a rich person.

            3. Anonymous Coward
              Anonymous Coward

              Re: Interesting idea

              I'm not sure if people read what you said properly, Macrorodent, because as stated, I agree with you. I also find it absurd to believe that 99.9% of climate researchers have been persuaded to join a global conspiracy promoting a fake climate change problem. What I believe is that 99.9% of climate researchers have NOT joined a global conspiracy (Occam's Razor decrees that the simplest possibility is usually the likliest) , therefore th claims of most climatologists that we have a climate change problem and that human activities are part of the problem is almost certainly true. Not sure why anyone would downvote you on that unless they are climate-change deniers.

              However, I must disagree with an earlier poster who commented on what "the elephant in the room.." is. IMHO the elephant in the room is that across the board insect numbers have been dropping rapidly, removing the underpinnings of most of the land-based ecosystems. Arguing over whether using hot silicon to store energy is better or worse than some other system seems to me a bit like arguing over precisely how the deckchairs should be arranged on the Titanic. Just store the damned energy so it that what's produced can be used more efficiently! If we run out of things to eat because the biosystem is collapsing around our ears, it'll reduce our need for power storage (or anything else) rather finally.

            4. Qarumba

              Re: Interesting idea

              I challenge you to find a list of all climate researchers, of which there must be at least 1000 on it and indicate those who are "persuaded" and the one or more who has not been "persuaded".

              Also climatology is no longer a science, it is a belief system. In any scientific field you can question any conclusion without being called a denier!

              Whilst most of us agree the climate is changing, as there is sufficient evidence for that, some of us would like to question how you can prove that the majority of that change is caused by mankind.

              Once convinced, some of us would like to see what the optimal solutions might be i.e. work with it, or work against it.

              At the moment the panic reaction is to call everyone who uses fossil fuels evil and tax the blazes out of the poor while providing eye-watering subsidies to the wealthy (e.g. solar panel subsidies that could only be afforded by the relatively wealthy).

              Of course anyone on the IPCC jetting all over the world to exotic locations for a chat are clearly exempt!

              1. David 18

                Re: Interesting idea

                @Qarumba

                "Also climatology is no longer a science, it is a belief system. In any scientific field you can question any conclusion without being called a denier!"

                I thought I was the only one! My biggest problem with the whole debate is the language of religion being used in science. Anyone (going back a few years now) who questioned that proven unreliable computer models were not scientific proof was pilloried. Disgusting, when directed at eminent scientists.

                I have been labelled a Creationist Brexiteer by virtue signalling arty types (who now suddenly "FL Science" without any concept of scientific method) because I have some reservations. (I am an atheist, liberal remainer btw with a lifetime of concern for the environment and pollution by nastier things than plant food!).

                A long time ago I did ponder whether the whole thing was cooked up to make people not want oil as it was running out anyway, and making people frightened to use something works a damned sight better than telling them they can't.

                In the last year or so, I have come to think that it probably is happening - there is some good science happening after all, and the models are just about starting to reflect reality.

            5. TheVogon

              Re: Interesting idea

              "1/ : yes. While truth is not determined by majority vote, I find it completely absurd to believe 99.9% of climate researchers have been persuaded to join a global conspiracy promoting a fake climate change problem."

              It's >97% actually: http://iopscience.iop.org/article/10.1088/1748-9326/11/4/048002

          4. TheVogon

            Re: Interesting idea

            "1/. Is carbon dioxide really affecting climate significantly?"

            That hasnt been in any scientific doubt whatsoever for at least 2 decades now.

            "2/. If it is, is the cost of reducing it greater than dealing with the cost of climate change?"

            The models show it is much cheaper to do something about it than to experience it.

            "3/. If it is, zero carbon nuclear power is already cheaper than windmills "

            Nope - nuclear power is way more expensive than renewables.

            3/(sic). Adding storage to renewable energy simply adds more cost.

            That cost is offset becaise because you need less non renewable and less peak generating capacity if you can store energy.

            "The answer is of course that governments - and the EU especially - are not actually interested in lowering CO2 emissions."

            Well they are doing quite well at it compared to most of the rest of the planet.

            "Presumably they know that CO2 does not affect the climate unduly."

            I doubt that they dispute science that is not doubted by a single recognised scientific institution on the planet. You would have to be a moron on the level of Trump to think that.

            "Germany STILL has more hydro and nuclear power running than the UK - in the highest CO2 emissions of any country in Europe"

            Germany is on 36% renewables and about 12% nuclear (The UK figures are ~ 30% and 15%). However Germany generates about 40% of it's electricity from coal - with corresponding high CO2 emissions.

            1. Alan Brown Silver badge

              Re: Interesting idea

              >> 3/. If it is, zero carbon nuclear power is already cheaper than windmills "

              > Nope - nuclear power is way more expensive than renewables.

              It doesn't matter if it is or isn't. Renewables can't generate enough electricity to replace carbon.

              They could just about (if all stops are pulled out) match electrical generation of the first decade of this century but when you gun for all the carbon sources (transportation, heating, industrial processes) you'll need 6-8 times more than that.

          5. Anonymous Coward
            Anonymous Coward

            Re: Interesting idea

            1 - Yes, CO2 is really significantly affecting the climate.

            2 - The cost of dealing with it, while significant, is considerably more than dealing with cost of climate change*

            3 - I'm in agreement that (modern, safe(er) ) nuclear power should be part of the mix, but putting all our eggs in that basket isn't very clever either

            3 (again! :) ) Not necessarily - part of the overall cost of renewables lies in their intermittent nature and the need to store / release excess energy when required. The basic production cost has been dropping massively and TCO won't be that far off nuclear

            I'm not disagreeing that the energy / subsidy market can be deeply skewed by governments, but that is true of all energy types. If there's some energy form that's going to be inefficiantly subsidised, I'd rather it be renewables than oil/coal (as in the US and oil-producing countries)

            *This is readily backed up by numbers in the reinsurance industry. Industry losses from climate-change related natural disasters is ALREADY significantly higher in the last couple of years than the previous 10-15 years. That's hundreds of billions being wiped off the balance sheets of mutual funds, pension funds etc invested in reinsurance, as well as increased insurance premiums all round and necessity of strengthening/rebuilding infrastructure costing many billions out of the pockets of property owners and taxpayers.

          6. JLV

            Re: Interesting idea

            Germany’s fail is that climate change is too much of a problem to allow the Greens much say in solving it. We agree on that much.

            For the rest, your ranty ramble is fairly content-free. If climate change is happening, something accepted by almost all scientists in the field, costs will be immense over time. Think of the effects on agriculture and losses from coastal real estate flooding.

            All for what? To resist changing the way we generate energy? Yes, it will change economies and yes there will be losers, but people will end up being employed in the new jobs, new companies will grow and life will go on pretty much as before. If youve been paying attention you realize a lot of hardnosed capitalist corporations ARE increasingly banking on climate change being a problem. Because, well, the math and science add up. If it’s happening then it’s just a physical phenomenon, not a political one.

            But, yeah, just keep on putting your head in the sand cuz it doesn’t fit your world view.

          7. Alan Brown Silver badge

            Re: Interesting idea

            1: Yes - and in ways you probably don't realise

            - forget temperature changes, the oceans have increased 30% in acidity in the last 200 years (pH is a log scale) and zooplankton are having trouble forming shells. In geological history, every time that's happened there's been a global anoxic event and the consequences for life on land have been severe (in the short term it would also cause an oceanic food chain collapse which means lots of starving people) - It's all there in the rocks.

            2: See above. How well can our species (and most others) cope with a reduction of atmospheric oxygen to 18%?(equiv 4000 feet at sea level) 16%? (equivalent 8,000 feet at sea level) or lower? Half the planet's breathable oxygen comes from the sea and during anoxic events the rocks show it's typically dipped to 13-14% (10,000 feet seal level equivalent). Can we cope with half the land area of the planet being rendered effectively uninhabitable?

            The heat - of water, not air - is a real problem.

            Tongues of warm water coming in from the Atlantic are destabilising methane clathrates on the Siberian continental shelf/margin (google for "laptev methane emissions") - and whilst what's coming out _now_ is relatively minor (the Russian establishment has started trying to play it down after blanking all coverage for 6 years and they still won't allow independent investigators into the areas), bear in mind that 20 years ago scientists were saying that all such emissions would dissolve into the water coloumn and it would be impossible for gas to make it to the surface (the plumes were about 1km wide at the surface in 2011) - what should worry you is that as the clathrates gas out, it makes the ice that remains porous, more and more unstable and more likely to break loose in a submarine landslide if there's an earthquake - which happen relatively regularly across the arctic.

            Submarine landslide-induced mass methane emissions have happened before - we know the most famous of them as the "Storegga Slides" and those were right on the knee point of warming at the start of our current interglacial period (after the slides, temperatures shot up sharply as did sea levels) - only this time there's the added fun of somewhere between 5-25gigatonnes of methane (carbon) that we can't afford to be added to the atmosphere to think about as well.

            The Global Methane Survey announced a few years back that they'd found 25% more methane in the atmosphere than they could account for from their satellite surveys and blamed it on possible farm animal emissions - but they didn't know about the Laptev Sea and their instruments weren't tuned to pick up methane over water, nor were the satellites in a high enough orbit to measure it anyway (they tried to recheck the raw data when it was brought to their attention (The reaction when shown the reports out of Russia before things clammed up was "What the? Uh oh!").

            There's a new methane survey underway using new instruments but it will take at least a couple of years to see if the "mystery" sources are clathrates. If they are, we may already have _at least_ 3-5C locked in.

        3. Lusty

          Re: Interesting idea

          The local hot water storage is a great point, but as is EVs. If you remove the requirement for heating from your power consumption then the relatively small remainder (given low power modern gadgets) could easily be handled by the battery in a modern EV overnight. If every house had on average one EV connected you've already solved the overnight problem at grid scale.

          ML would be able to predict EV usage to give you sufficient juice to get where you're going in the morning, and once there you can charge from the solar again. A simple routine could cope with exceptions, perhaps linked to your diary - certainly O365 can supply destination addresses.

          We need to stop thinking big infrastructure and start thinking small and scalable. In IT speak, let's start scaling out instead of scaling up because it's almost always easier and cheaper. It'll even mean a lower capacity grid, so infrastructure costs will be lower accross the board. We all already have meters (many of them "smart") in homes to watch where power is flowing.

          And don't even get me started on rainwater capture at the property level rather than moaning about water shortages...

          1. Jellied Eel Silver badge

            Re: Interesting idea

            The local hot water storage is a great point, but as is EVs. If you remove the requirement for heating from your power consumption then the relatively small remainder (given low power modern gadgets) could easily be handled by the battery in a modern EV overnight. If every house had on average one EV connected you've already solved the overnight problem at grid scale.

            Taking it further, if the EV was parked indoors, then waste heat from battery warmers & charging could heat the home.. Or require less energy because the car's warm. Problem though is typical EV usage would be to discharge during the day/evening as it's driven, so charged at night. And in the UK, problematic if you don't have anywhere to park and charge your EV.

            It really needs an engineering approach to the problem. First, define the requirements. That's pretty much cheap, reliable power because we depend on it as an input cost to pretty much every activity, and for our quality of life. Solutions that increase cost obviously aren't fit for requirement.

            Lobbyists get around this issue by externalising costs, or just outright lies. DECC did this with their levelised costs comparisons for generation by type to try and flatter renewables. As well as being expensve, renewables still have the fundamental problem of being unreliable, hence suggestions like this to 'fix' the problem by adding a lot more cost. That makes no economic or engineering sense.

            That kind of lobbying can also extend to other areas. So nuclear is very low carbon. But concrete! Ok, so yes, it needs a bit. But then so do windmills for foundations, pads for support kit etc. But conrete is also fun. So CO2 production comes from the process of calcination. Heat calcium carbonate to make calcium oxide for cement. So use low carbon energy for that process and it's CO2 debt is greatly reduced. And then reduced further because that oxide absorbs CO2 again over concrete's lifespan. That was a fun realisation discovered by the bionauts in Biosphere 2. CO2 levels in their dome was dropping because their concrete was absorbing it.

            Who knew concrete was a green, sustainable form of carbon capture and storage?

            But such is politics. The concrete thing is one small part of the FUD, especially as the CO2's mostly around cement production, not the sand and aggregate that makes up most of the concrete volume. Either way, nuclear is still by far the cheapest and greenest low carbon generation source.

            1. Rustbucket

              Re: Interesting idea

              When standard concrete absorbs CO2 the concrete is weakened and becomes more prone to spalling.

              Another externality to the increase in atmospheric CO2 levels -- we can expect out concrete buildings, dams and bridges to deteriorate earlier than they otherwise would.

            2. Pen-y-gors

              Re: Interesting idea

              @Jellied Eel

              "Taking it further, if the EV was parked indoors, then waste heat from battery warmers & charging could heat the home"

              An interesting idea. Hoe exactly does that work on the 6th floor of a block of flats? Bigger lifts? Crane outside the window to hoist the car up?

              1. Anonymous Coward
                Anonymous Coward

                Re: Interesting idea

                @Pen-y-gors

                Underground car parks with charging points?

                Probably won't work for existing blocks of flats, or could do with a good engineering solution to retrofitting them under buildings.

                An interesting conumdrum for engineers.

            3. Alan Brown Silver badge

              Re: Interesting idea

              "especially as the CO2's mostly around cement production,"

              If you have molten salt nuclear, the extreme (800-900C) heat is an ideal replacement source for carbon-sources.

              Ditto on manufacturing carbon-based fuels for things which can't (easily) be electrified - such as longhaul aircraft.

              And then there's the small issue of sidestream production of an inexhausitble supply of helium & xenon, plus using up all that pesky throrium waste which is making rare earth mining impossible in most places, which in turn makes all those other rare earth products a lot cheaper/easier to obtain.

          2. Glen 1

            Re: Interesting idea

            >If you remove the requirement for heating from your power consumption

            In places where PV is most cost effective, air conditioning (for cooling) is a big current draw.

            The whole point of leaving something to charge overnight is that you know you've got a full tank in the morning. Not to mention the economy7-esq night time power is cheaper.

            I suppose that will change if solar gets a bigger slice of the pi, but with the UK's climate it's more cost effective to go with wind.

            Or y'know, stop pissing about and go nuclear properly.

            1. Alan Brown Silver badge

              Re: Interesting idea

              "In places where PV is most cost effective, air conditioning (for cooling) is a big current draw."

              Having spent time living in such places - the use of brute force cooling is only one approach.

              People have lived in such areas for thousands of years and engineered a bunch of approaches to keeping cool that usually involved thermal chimneys and natural venting. (Look for chimney structures with the tops painted black - these aren't smokestacks, the solar heated tops pull air up and out of the buildings - very common in older areas across asia and the middle east - and the Persians had cooling systems down to a fine art 3000 years ago)

              Sure, you can stick an Aircon unit on the side of a tin box that acts like an oven, bit it's not much harder to take a few leaves out of old designs and usethe above coupled with double skinned designs that use the heat to pull air through the building in such a way that everyone's kept cool.

            2. Alan Brown Silver badge

              Re: Interesting idea

              "The whole point of leaving something to charge overnight is that you know you've got a full tank in the morning. Not to mention the economy7-esq night time power is cheaper."

              The power requirements of an all-electric vehicle fleet more than match the pre-existing UK power requirement.

              Economy7 "offpeak" load might well become the highest load point of the cycle if everyone's charging their cars overnighht. You can pretty much rest assured that no matter what else happens, "offpeak" rates as we know them will effectively cease to exist and the spike of everyone putting their kettles on during the coronation street ad breaks will be a minor bli in the demand graph.

          3. Nonymous Crowd Nerd

            Re: Interesting idea

            Yes. Yours is ultimately the answer we're looking for, but, perhaps not all that surprisingly, it's deeply unpopular with the encumbent energy suppliers (the "Big Six").

            They are, for instance, oddly challenged when it comes to measuring how much power a micro-renewable system in a domestic installation actually exports to the grid.

            Another handy method they use is to worry about the capacity of local transformers and how much the local voltage will rise if more power is generated in remote locations.

          4. Cynic_999

            Re: Interesting idea

            "

            We need to stop thinking big infrastructure and start thinking small and scalable. In IT speak, let's start scaling out instead of scaling up because it's almost always easier and cheaper.

            "

            Huh? Small-scale production is less efficient and more expensive than mass-production in just about everything, and energy production is no exception. Individual wind and solar power sounds all very nice until you do the arithmetic and realize that it is an expensive way of generating insufficient power (apart from artificial government=taxpayer subsidies). You'll also find that you cannot build your own car, make your own clothes or grow your own vegetables any cheaper (or greener) than buying the mass-produced stuff. It might make you feel all green and self-sufficient, but that's just a foolish illusion. All you really get is a bit of self-satisfaction from the DIY.

            1. jmch Silver badge

              Re: Interesting idea

              "Huh? Small-scale production is less efficient and more expensive than mass-production in just about everything, and energy production is no exception."

              True, but what you lose in efficiency you more than make up for in volume.

            2. Pen-y-gors

              Re: Interesting idea

              @Cynic_999

              Small-scale production is less efficient and more expensive than mass-production in just about everything, and energy production is no exception.

              Very true. But it's also massively more flexible and extensible. Need more leccy? Add a few panels or an extra turbine of some sort. Or spend £30+ billion and wait 20 years for a new nuclear station. Base cost should only rarely be the most important consideration.

              1. Cynic_999

                Re: Interesting idea

                "

                Very true. But it's also massively more flexible and extensible. Need more leccy? Add a few panels or an extra turbine of some sort. Or spend £30+ billion and wait 20 years for a new nuclear station

                "

                All well and good if you have both the money and roof space to add a few more panels, and are prepared to severely ration your consumption over the UK Winter (just when more electricity is needed). But it's probably less than 20% of the population who would even be able to do it, let alone those who would find it desirable.

                But if you think it's so great, I am prepared to try it. I'll let you convince my landlord and the owner of the block of flats I live in to allow you to put PVs on the roof, and you can then pay to install them. In return you can have all the money I'll save from having them in perpetuity. Good deal? While you're at it, you can swap my petrol car for an EV and negotiate with my council to install a recharging point somewhere I am guaranteed to be able to park overnight. Again, you get to keep all the money I'll save (less the amount I have to spend on the occasional journey that's as yet impractical to do in an EV).

          5. devjoe

            Re: Interesting idea

            Yup I think there's a huge potential in local generation and small scale storage too.

            But one big issue with the EV charging idea; you're at work during the day when your solar generates excess power - which means, your EV isn't at your home and can't charge on "free" electrons. Once the sunlight is gone, you come home and plug your EV in...

            How do you solve that?

            1. Lusty

              Re: Interesting idea

              "But one big issue with the EV charging idea; you're at work during the day when your solar generates excess power - which means, your EV isn't at your home and can't charge on "free" electrons. Once the sunlight is gone, you come home and plug your EV in..."

              The concept of "at work" is very quickly changing. As is the idea of a commute. Long term I don't expect all this unnecessary travel to continue at all. My (global) employer is about to reduce building count fairly drastically in the UK to account for changes in working patterns.

              But to more directly answer your question for right now, the daytime power can easily be used for heat transfer either from the house to a water tank, or from outside to a water tank so that you have hot water while you're at home. In summer, we should also be using heat exchangers to move hotness from indoors to the hot tub. Parking at the office could easily be hooked up to solar power too, which can also double up as a roof for the carpark and a water harvesting platform to solve the "water crisis".

              To answer another part of the thread, we very rarely need a full tank in the morning. Hence why the ML in the cars allow them to work out how much to keep in reserve. If every house is hooked up we all share the supply and the demand. There are a surprising number of people on this thread who seem to be resiting any and all change and clinging to the large infrastructure. The very notion that PV only works at large scale is ridiculous. Its very nature means it's a linearly scaleable resource, but the proximity to usage can and will reduce infrastructure cost and complexity.

              1. Cynic_999

                Re: Interesting idea

                "

                There are a surprising number of people on this thread who seem to be resiting any and all change and clinging to the large infrastructure.

                "

                Maybe it's because we have done the arithmetic and plugged in some real-world figures. And discovered that for the vast majority of people it simply does not compute either from a practical viewpoint or a cost viewpoint.

                Come up with realistic figures for (a) how many MWh the average household with an electric car would need per year and (b) how many MWh the average roof full of PVs will generate in the UK (at its half-life point). Then give a realistic estimate of the cost of the installation and its expected lifetime.

                Then see how realistic and cost-effective your "solution" is. And that's without taking into account the vast proportion of flat-dwellers who have no roof and/or cannot park their car close enough to charge from the home, or do not have a roof suitable for efficient PV installation.

                It's similar to the notion that we should all grow our own vegetables. All great when you are hand-waving, but not so great when you go into the details of carrying it out.

            2. Lusty

              Re: Interesting idea

              Also, you're assuming the EV couldn't drive home and charge itself while you work...

            3. Alan Brown Silver badge

              Re: Interesting idea

              " when your solar generates excess power "

              have you worked out _how much_ solar panel you actually need to take the average EV on your daily commute?

              At northern european latitudes it's way more than the average house rooftop and the panels aren't particularly green (hydrofluric waste is threatening the water supplies of around 20 million people)

              Unless electricity suddenly goes up to 70p/kWh, The unsubsidised payback period for any solar panel is about 3 times longer than the lifespan of the panels - and as governments are progressively reducing the subsidies it's unlikely anyone "investing" in them as a hobby installation will ever break even.

              1. Lusty

                Re: Interesting idea

                "have you worked out _how much_ solar panel you actually need to take the average EV on your daily commute?"

                I'll do you one better. A friend of mine with a modest PV installation not only powers his house and car but also sells quite a bit back to the grid. He even started buying toys like electric bikes to use some of the excess. No need to work it out, I've seen it in real life and it's more than sustainable. He doesn't skimp on the miles in his car either.

                1. Charles 9

                  Re: Interesting idea

                  How about at night when the sun's down? Or in stormy conditions when the clouds cover the Sun? Or in the winter when the sun isn't out so long? Can you show ALL the numbers that render him net-positive per annum?

                  1. Lusty

                    Re: Interesting idea

                    Yes, he showed his annual usage bill. It's not hard to be net positive on energy these days. All lighting is LED which uses almost no power. With heat exchangers it's quite easy to use power only to transfer heat from the air or the ground rather than consuming power to create new heat, a much more efficient approach. 1/3 of the power in the UK grid is now renewable so I don't understand why such an intelligent bunch as Reg readers find it so hard to believe renewables work just fine and are sustainable. It's not even like we've used a huge percentage of our land or coast for this. There are solar farms around most towns now, sure, and there are offshore wind farms in conspicuous locations where the infrastructure exists to manage them. The vast majority of the country is untouched though.

                    1. Charles 9

                      Re: Interesting idea

                      Simple. Because there are concrete counterexamples. The Ivanpah solar thermal plant in California is the largest in terms of capacity in the world (392MW--funny, they won't say whether it's thermal or electric). It spans 3500 acres (1420 ha). Last I read, that's supposed to be enough to power some 100,000 homes. Trouble is, even back in the 2010 Census, Los Angeles County alone ran some 13 million homes (and probably will be more come the 2020 Census).

                      "1/3 of the power in the UK grid is now renewable"

                      But that leaves the remaining TWO thirds to cover. AND it would be a good idea to check how well your renewables handled the worst-case condition of just having covered the Winter Solstice: shortest day of the year.

          6. Alan Brown Silver badge

            Re: Interesting idea

            "We need to stop thinking big infrastructure and start thinking small and scalable. "

            Small and scalable is hellaciously expensive compared to molten salt nuclear deployments.

            Get the water (and sealed fuel rods) out of the nuclear cycle and you remove almost everything that can go wrong. Using refined Uranium is on par with powering your car using TNT (yes Thorium converts to uranium in the reactor, but it STAYS in the reactor.Any attempt to remove the intermediate stages is noticeable as a dramatice power output drop and all the nuisance dangerous stuff stays in the reactor until broken down further too). You can still use steam turbines outside the nuclear loop - but if there's a steam explosion it's just that. no nuclear material involved and no different to one at a large coal-thermal station (and you don't have to limit your operating temperatures due to boric acid and friends, so it's more thermally efficient, which means no dependency on big wet heatsinks that cause derating in hot weather or leave you at risk of being flooded out.)

            The amount of money that's been spent on renewables in the UK _alone_ would have paid for a dozen new nuclear power stations - which would have a far greater sustained output than everything that's been installed combined. Rewnewables might just match electrical production of 2001, but when you go more-electric, less carbon, you're going to need 6-8 times more electricity than that anyway.

        4. Robert Helpmann??
          Childcatcher

          Re: Interesting idea

          I thought this was relatively inefficient. Another storage scheme is stacking concrete blocks using an electric crane and then allowing them to fall while recapturing some of the energy. It's more efficient (about 85% efficiency) than this is going to be. Lithium-ion batteries are about 90% but are nowhere near as stable. Looks like the sun inna box is the worst of available storage methods.

        5. Alan Brown Silver badge

          Re: Interesting idea

          "But that involves the 'N' word, which most Greens hate.. even though it makes far more economic sense, especially if electricity demand keeps growing."

          The fast way to convince Greens is to ask them to calculate how much electricity is needed vs how much "renewables" can produce, then ask them what the cmmon causative or exacerbating factor in every single civil nuclear power incident to date has been (the answer is water and MSRs eliminate it along with 99% output waste, 89% input waste (@3% enrichement) and the military's ability to keep churning out hydrogen bomb casings (U238) - weaponisation of the currnet nuclear cycle happens long before fuel ever sees the inside of a conventional nuclear reactor and the scaremongering about reprocessing is mostly aimed at keeping people's eye off the ball as to where the real threat is - civil reactor-bred plutonium is a bastard mix of isotopes that's virtually impossible to make bombs out of)

          1. Dr. Mouse

            Re: Interesting idea

            The fast way to convince Greens is to ask them to calculate how much electricity is needed vs how much "renewables" can produce

            Most will come back with "We need to use less electricity, then the renewables will work"...

          2. Lusty

            Re: Interesting idea

            "The fast way to convince Greens is to ask them to calculate how much electricity is needed vs how much "renewables" can produce"

            They've done it, years ago. The answer was "plenty". We're a good way along that journey now if you look at the proportion of renewables used in the grid. It's higher than you think, but I doubt you'll bother to look.

            1. Charles 9

              Re: Interesting idea

              Don't accept "plenty". Unless it's at least "enough" (complete with concrete numbers even under worst-case conditions to prove it), say that isn't sufficient. Unless you can shut off the coal, oil, and gas without Standing on Zanzibar, it just won't cut it for Joe Ordinary.

  3. steelpillow Silver badge
    WTF?

    Photovoltaic?

    Natural hot-rock exploitation uses water/steam or a similar working fluid to turn the heat into mechanical work and drive generators. Why change to photovoltaics?

    1. Trollslayer

      Re: Photovoltaic?

      That's fine in Iceland but what about the middle of Essex?

      1. ibmalone

        Re: Photovoltaic?

        I believe the question was about the mechanism the storage uses. It converts the heat from the silicon to electricity via photovoltaics. When dealing with hot rocks, or pretty much anything (see coal and nuclear power stations too), steam and turbines are used for the conversion. This is dealt with on page 5 of the paper (which I think is open access):

        One critical question that arises with the TEGS-MPV approach, however, is why MPV is chosen as the heat engine instead of a turbine, which could likely be more efficient at lower temperatures. There are three reasons for this: (1) turbines that take an external heat input and operate at high efficiencies (> 50%) do not currently exist. Although it may be possible to develop such a system, a large barrier to commercial deployment exists, as it would require a large OEM to undertake an expensive (>$100 million) development effort for a high-risk application. On the other hand, existing III–V cell manufacturers are positioned to facilitate the commercialization and deployment of the described MPV power cycle with much less investment. (2) The cost of our proposed MPV system can be much lower than that of a turbine. (3) The speed with which turbine-based heat engines can ramp from zero to full power is on the order of tens of minutes to an hour. However, with this TEGS-MPV approach, as is illustrated in Fig. 2, the MPV modules can be actuated in and out of the light on the order of seconds, which could provide much greater value to the grid via load following, thereby increasing revenue.

        1. itzman

          Re: Photovoltaic?

          Combined cycle gas turbines operate at >60% efficiency, so that is lie for a start. No reason they couldn't take their gas input from a separate gas heat exchanger.

          1. ibmalone

            Re: Photovoltaic?

            Combined cycle gas turbines operate at >60% efficiency, so that is lie for a start. No reason they couldn't take their gas input from a separate gas heat exchanger.

            Presumably would drop the efficiency though? Overall I suspect the aims are: 1.This is quite hot, hotter than most power sources, so the dynamics may differ. 2. Responsiveness, for a storage rather than supply solution you don't want a ramp-up time. 3. Photovoltaics can be smaller and possibly more easily maintained, but only having skimmed I'm not sure what size storage they're aiming for. (Got to be reasonably big to make insulating molten silicon practical one would think.) Papers like this do tend to go for quantity over quality on the justifications though, there's usually one or two core reasons and the rest are filler.

            Overall doesn't seem an unreasonable idea, silicon is cheap. Lithium is nice for batteries because it's light, not primarily for efficiency or volume.

      2. Blofeld's Cat

        Re: Photovoltaic?

        "... what about the middle of Essex?"

        IMHO there are parts of Essex that would be greatly enhanced by the addition of, or indeed conversion to, a volcano.

        (Former Harlow resident)

        1. Sgt_Oddball

          Re: Photovoltaic?

          It then has the added benefit of being highly desirable to megalomaniac bond villians evil geniuses tech investor types when said volcano gets decommissioned, also meaning its greener still (since it wouldn't need much redevelopment.)

    2. the Jim bloke
      Flame

      Re: Photovoltaic?

      geo thermal is depletable at the rate we want to use it, unless you are in an active area... It is great for people who live amidst the smell of rotten eggs, but less so elsewhere.

      Even on Lihir Island, a dormant volcano on the ring of fire, with steam venting from the ground, the geothermal generators power output dropped over time and was insufficient to run the gold mine processing plant.

      1. Sgt_Oddball

        Re: Photovoltaic?

        The wife constantly complains over a ring of fire smelling of sulfur and venting steam... I can see why no one would want to be closer.

    3. Primus Secundus Tertius

      Re: Photovoltaic?

      @steelpillow

      I have to admit I did not properly understand the scheme until I read the paper cited in the article.

      Molten silicon (the element, not the oxide aka silica or sand) is being pumped around by electromagnetic arrangements with no moving parts apart from the molten silicon. Its "low" temperature is 1,500C and its high temperature 2,900C. Radiation and "solar" cells are a plausible way of extracting energy from the high temperature phase, rather than traditional heat exchangers.

      Years ago I worked on software for a nuclear power station. The CO2 reactor coolant then generated steam at 800C -- red heat -- and high pressure.

    4. oldcrab

      Re: Photovoltaic?

      "Natural hot-rock exploitation uses water/steam or a similar working fluid to turn the heat into mechanical work and drive generators. Why change to photovoltaics?"

      Because potentially the capital cost should be much lower. Also from a thermodynamic point of view it should be more efficient.

    5. Alan Brown Silver badge

      Re: Photovoltaic?

      "Natural hot-rock exploitation"

      Tends to fall off rapidly unless you happen to be right on top of a "hot spot".

      Even drilling into the side of a magma chamber doesn't help much. New Zealand tried that.

      Rock is a _very_ good insulator. When you tap off heat it takes a long time to "refill" and the more you take the longer you need to wait.

  4. Anonymous Coward
    Anonymous Coward

    "cheaper"

    Is never a goal to aim for of itself, if safety and reliability also go out the window. XD

    1. bombastic bob Silver badge
      Meh

      Re: "cheaper"

      Well, a 10:1 improvement in the cost of the infrastructure for "just the storage" OBVIOUSLY leaves out the cost of conversion from heat to electricity (the article even said so, more or less). This latter part, 2nd law of thermodynamics notwithstanding, has been THE problem all along in making electrons move through wires so that we can watch TV and read by electric light... and in some cases, heat various rooms in the house that aren't practical to heat any other way.

      And if you're going to go THAT far, we might as well use URANIUM to produce the heat in the FIRST place. Until, of course, hydrogen fusion reactors become practical.

      It's obvious that politics of the day are driving all of this.

      /me plays "Baby it's cold outside" - not simply because it IS getting colder, and will continue to get colder, on average, in the Northern hemisphere, until ~2040 due to the ~70 year temperature cycle, but MOSTLY because I heard some people whining about that song recently and so I'm having fun with it.

      To the scientists who suggested 'hot rock' storage: Nice try. How about 'Nuclear' instead? Nuclear doesn't generate CO2, the thing you fear the most. But wait, it's not in line with the POLITICS, now is it? Heh, yeah, pointing out the obvious again. I think I prefer FREEDOM.

      1. Pen-y-gors

        Re: "cheaper"

        How about 'Nuclear' instead? Nuclear doesn't generate CO2, the thing you fear the most. But wait, it's not in line with the POLITICS, now is it? Heh, yeah, pointing out the obvious again. I think I prefer FREEDOM.

        Okay, I'll take the bait and try to explain.

        Is your idea of FREEDOM being required to get your electricity from a single Japanese company who build and run a massively expensive and potentially lethal generation facility on your doorstep, which is liable to catastrophic failure (or even non-catastrophic failure) - one bad glitch in a nuclear power station and a million people have no electricity until it's fixed. One really really bad glitch and a million people probably won't ever have to worry about the electricity supply (or anything else) ever again. And when they're the only game it town they set the prices at whatever they want. The wonderful Hinckley C has a guarantee that they will get £92.50 per Megawatt hour, index linked, for the next 35 years. UK electricity companies are currently paying under £40 for French nuclear power. Large-scale wind currently costs around £50/MWh. Hinckley will cost UK consumers £50 billion more than it needs to. And you will pay it whether you want to or not. That's FREEDOM!

        Not my idea of FREEDOM, but hey, whatever floats your boat.

        Or maybe FREEDOM is having a large network of connected small-scale, varied, renewable generators with a range of doorstep and locally-ish storage to smooth things, so you have the FREEDOM to actually use electrical appliances when you want.

        And on a related point - "Nuclear doesn't generate CO2" - only true-ish at the point of generation. Over the lifetime of a reactor, once you include the necessary construction, mining, refining, decommissioning and waste-disposal as well, then Nuclear generates a lot of CO2. Depending on the concentration of the ore it can easily exceed the lifetime CO2 outputs of every know current type of renewable. So, no, not a magic wand solution either.

        1. Tomato42

          Re: "cheaper"

          as if there were no massive industrial disasters related to coal, oil or gas...

          we would need to average one Chernobyl a year for nuclear to be in the same ballpark of deaths caused per MWh of electricity produced as the above three

          1. Anonymous Coward
            Anonymous Coward

            What's unsafe about molten silicon?

            It can't explode, if the containment is breached due to an earthquake or similar there is little or no environmental impact, it can't be stolen and have its energy repurposed into a destructive weapon. I don't know enough about this to say whether or not it is practical, but I can't imagine there are any legitimate safety concerns. Batteries and pumped hydro are far less safe, that's for sure!

        2. Alan Brown Silver badge

          Re: "cheaper"

          The UK needs 60 more nuclear power plants, not just one. look at Gridpower and compare the nuclear sources with renewables and then with gas/other sources.

          At that point, when one fails the others pick up the load - and unlike japanese operators who refuse to admit they have a problem and won't give the ok for rescue teams who are primed and waiting to leave Okinawa with emergency generators that could have salvaged the entire mess, UK operators have tended to favour safety and sense over national pride and public honour.

          > The wonderful Hinckley C has a guarantee that they will get £92.50 per Megawatt hour, index linked, for the next 35 years.

          Yes, and?

          > UK electricity companies are currently paying under £40 for French nuclear power.

          Over maxxed out submarine interconnectors, of which only so many can be built unless you start making chunnels just for them. (or take over the chunnel) - and in any case the French only have so much overcapacity anyway.

          > Large-scale wind currently costs around £50/MWh.

          But unfortunately there's only so much you can build and only so many places you can build it - and you need 800-1000 land-based wind turbines to match ONE Hinkley C (more if you factor in total annual wind output of less than 20% nameplate rating)

          > Hinckley will cost UK consumers £50 billion more than it needs to. And you will pay it whether you want to or not. That's FREEDOM!

          OK, don't build it. Then you can explain to consumers why on the coldest, stillest, least cloudy night of the year, the power went off, gas boilers which all use electronic controls and rely on electricity stopped working and people started freezing to death.

          WRT the other claims about nuclear - Uranium is a silly material for nuclear power. It was only used for the original power reactor (the Nautilus) because that was what was available thanks to weapons programs (he would have preferred to use thorium) and it alarmed the hell out of the guy who built it that

          the things got scaled up to stupidly large sizes (boiler stresses go up with the 4th or 5th power of the generatiion capacity), plus the waste issues - so he built a better one, tested it, proved it was walkaway safe and tested it for over a decade - and got fired for his efforts.

          Thorium is readily available, no enrichment required, with hundreds of thousands of tonnes looking for a buyer right now - and it's virtually impossibvle to weaponise. You need some uranium to get your reactor started but once the reactor's running it's self sustaining on thorium and as a nice side benefit it eats conventional "high level nuclear waste" fuel rods and all so it can be a nice garbage disposal for our previous inefficient methods.

          Our current nuclear fleet is on par with Neucomen's lifting engine in terms of techonlogical progress compared to Watt's improved engine that's the LFTR design. The fixation on using Uranium is the first thing that has to go (TNT vs diesel as fuel. Which would you prefer?), and the fixation on using water as moderator is next (radioactive steam is nobody's friend)

    2. Justthefacts Silver badge

      Re: "cheaper"

      It can’t be true that safety always trumps cost, when society resources are always limited. That’s not hard-hearted, it’s the opposite, to find the best way to save lives in the real world.

      Health in our society is currently funded at a level such that treatments are available at a level of Quality Adjusted Life Year = £15k. I won’t go through all the arithmetic, but the net is that making energy cost savings of just 1% would be allow re-deploying resources to save 200 lives per year in the U.K.

      Alternatively, road-safety measures operate on a target cost of spending £1.5M per life saved (equivalent to £50k per QALY). The same cost savings could be redeployed to save about 60 lives per year on the roads. Ideally government would take a more consistent view on its spending, but the general point is there.

    3. Anonymous Coward
      Anonymous Coward

      Re: "cheaper"

      That is of course why reliability has a cost as does safety.

      The world is not ideal. 100% safety means you never even get born.

  5. Trollslayer
    Thumb Up

    By George

    I think they have it!

    1. Anonymous Coward
      Anonymous Coward

      Re: By George

      Sadly not. The proposed system will be much more complex in practice compared to theory, there will be parasitic loads for control of the storage, and the theoretical efficiency will be well ahead of the real world. That's true for new and existing technologies.

      When you chain multiple conversion stages, you're multiplying inefficiencies. My former employers built a plant that (at near grid scale) used surplus renewable energy to dissociate water and create and store hydrogen, which was then methanated to make it useable as "green" gas in the gas distribution network or into a steam turbine to create electricity. Sadly the net efficiency was dismal, so although the technology works, there's simply no way it can properly scale to be material. And I think this will be the same - throw money at it, and it will work. But don't expect this to be viable in most situations.

  6. vtcodger Silver badge

    Lots of choices

    There are dozens of energy storage options out there, and many look great on paper. In practice? Often not so much. Lithium-ion's strong point is high energy density which is very important in a vehicle smaller than ,say, a cargo ship. But it's not necessarily a big deal for a fixed installation. In point of fact the preferred utility grade storage option is often pumped storage which is quite cheap (a few cents per kwh) if you use it a lot, have lots of water available, have suitable topography and don't mind losing about a quarter of your input energy to various inefficiencies. Pumped storage has very low energy density.

    A storage vessel for molten Silicon? Let's put it in your backyard, not mine. Same for Sodium-Sulfur storage which is actually in use here and there.

    1. Anonymous Coward
      Boffin

      Re: Lots of choices

      Pumped storage is great, but it does create a lot of local environmental disruption due to water withdrawls from rivers, occasional needs to tunnel through mountains and hills and damming of some streams.

      We have a couple pumped storage plants up in the Sierra Nevada.

      1. Korev Silver badge
        Boffin

        Re: Lots of choices

        El Reg did a rather nice Geek's Guide to Dinorwig Power Station

        . A great read if you haven't seen it.

      2. Anonymous Coward
        Anonymous Coward

        Re: Lots of choices

        Pumped storage can also be a terrorist target, if it is practical to breach containment and cause flooding. There isn't really anything for terrorists to target with molten silicon, breaching its containment isn't going to harm anyone unless the storage facility is 20 feet from your house. They can't "steal" the molten silicon and do anything with it since it'll cool down. It isn't worth enough to be worth stealing, either.

        Ditto for earthquakes, that could breach containment for either but one may flood entire cities and the other will let a bit of silicon escape into the surrounding soil where it will quickly cool and solidify, and can be either left in place (I don't think it is harmful to the environment?) or easily dug up and removed.

        1. Jellied Eel Silver badge

          Re: Lots of choices- DoS works for physical stuff!

          There isn't really anything for terrorists to target with molten silicon, breaching its containment isn't going to harm anyone unless the storage facility is 20 feet from your house.

          But this is supposedly grid-scale stuff, so risks becoming something we depend on. Which then means it becomes a potential target. Which then means risk assessments and security costs to prevent someone breaching the containment, adding water and watching the mess. Or just some unexpected failure leading to silicon soldifying and gumming up the works.

          (ISTR there's a form of silicon oxide that can explode in a pretty energetic manner as well.)

          1. ibmalone

            Re: Lots of choices- DoS works for physical stuff!

            (ISTR there's a form of silicon oxide that can explode in a pretty energetic manner as well.)

            Prince Rupert's drop? Don't think they've been successfully weaponised :)

          2. Anonymous Coward
            Anonymous Coward

            Re: Lots of choices- DoS works for physical stuff!

            Why would terrorists try to take out the containment for molten silicon, which would be underground and set in concrete so not exactly a "soft" target? They'd just need to reroute power around and they'd be fine, unless you took out a bunch of them (I assume rather than a giant one at a generating station you'd have a number of them distributed around the grid close'ish to renewable sources like turbine farms and utility scale solar.

            The same amount of explosive could take out an entire large city-scale substation, and be FAR more disruptive and expensive to repair.

            Terrorists generally want to kill people, not inconvenience them with a short term blackout. Those who want blackout type harassments (Russian hackers etc.) would probably find it easier to come in via the network and insecure SCADA links from the safety of their own extradition-proof country.

        2. Alan Brown Silver badge

          Re: Lots of choices

          " There isn't really anything for terrorists to target with molten silicon"

          Exactly the same arguments apply to molten salt nuclear systems.

          If you could cobble up more heath-robinson method of utilising nuclear energy than the water, molten metal and gas cooled ones we actually use, I'd be surprised.

          1. Anonymous Coward
            Anonymous Coward

            Re: Lots of choices

            We use the type of nuclear we do because we wanted more than just electrical output, we also wanted nuclear weapons. THAT'S why all the money was spent developing that system, if it wasn't for that we wouldn't have any nuclear plants generating electricity in the entire world.

    2. Alan Brown Silver badge

      Re: Lots of choices

      "There are dozens of energy storage options out there, and many look great on paper. In practice? Often not so much."

      It's just like engines - lots and lots of designs which promise to replace Otto and Diesel but in the real world they usually barely produce enough power to keep themselves spinning, let alone extract usable work (or they are incredibly fiddly/maintenance intensive - turbines replaced piston engines on aircraft despite using 30% more fuel because they're much lighter, much simpler, produce much more power and have far service intervals - these all add up to being more efficient overall because a 747-100 with Wasp Major engines(*) would have needed 10 of the things to barely get off the ground, had a range of 1500 miles and needed intensive service after every single flight (8-16 hours per engine)

      (*) The most powerful aviation engines to enter service - and spectacularly unreliable. Old 4 engine piston airliners would regularly complete a 6 hour flight with 3 engines working.and it took 40+ years for aviation authorities to agree that jets weren't that bad.

  7. DJV Silver badge

    Henry

    When I saw the name "Henry" I was expecting it to mean Professor Henry Brubaker!

  8. Tom 7

    Balls

    Spherical insulated water containers can also be used for storing heat for domestic use. As we get more and more renewables then there will soon be a time when cheap mains electricity can be used for space/water heating in domestic situations rather than gas or oil.

    Economy 7 storage heaters are another possible example. If we had proper smart meters that is.

    1. vtcodger Silver badge

      Re: Balls

      I'm not sure we'd want an actual sphere. Maybe a cylinder with rounded edges. The problem is that if the floor under the storage tank moves at all -- e.g. earthquake or subsidence -- the tank is probably going to try to move. Since it will likely weigh 500kg or more, typical interior walls -- at least in North America -- probably won't constrain its motion much, We'd probably prefer that our hot water storage tanks stayed put.

      My parents had one of those big tanks as part of a solar hot water installation. Per code -- doubtless written with typical tall, thin domestic hot water tanks in mind, that storage tank was securely strapped to an interior wall. It was pretty clear that if that tank decided to move, the wall was going traveling with it.

    2. ivan5

      Re: Balls

      As we get more and more renewables then there will soon be a time when cheap mains electricity

      That will be the day - if they ever do. The countries with a lot of renewable energy - Germany, South Australia, have the highest cost electricity in the world. Those countries with lots of coal fired generators have the lowest cost electricity in the world.

      The smart meters have one main function - to cut off your power when the renewables can't supply enough and they have to have rolling blackouts.

      1. Anonymous Coward
        Anonymous Coward

        Re: Balls

        You can't store enough heat in water for useful amounts of power without huge pressures, which makes them bombs no one wants to have in their home. There's a reason water heaters are required to have a pressure relief valve spec'ed at 150 psi.

    3. Anonymous Coward
      Anonymous Coward

      Re: Balls

      trouble is with the current economy 7 is that it works overnight when demand is low which is ok but come the evening the thing has already dumped all its heat

      1. JohnG

        Re: Balls

        "trouble is with the current economy 7 is that it works overnight when demand is low which is ok but come the evening the thing has already dumped all its heat"

        One answer to that is Economy 10: the timings vary between suppliers but typical cheap periods are 5 hours overnight, 3 hours in the afternoon and 2 hours in the evening.

    4. Anonymous Coward
      Anonymous Coward

      Re: Balls

      As we get more and more renewables then there will soon be a time when cheap mains electricity can be used for space/water heating in domestic situations rather than gas or oil.

      Why will it be cheap? The costs of the grid, or standby fossil generation, and the renewable generation all need to be paid (and the renewables increase total costs of the system). Just because something has a very low marginal cost of operation doesn't make it free - as Hinkley Point C is demonstrating.

      And there's another complication that battery storage and EV charging will flatten out short term wholesale market price variations, so the concept of having a lot of surplus power pushing down prices starts to diminish. Ofgem are already proposing various network code changes that will increase the fixed cost element of residential energy bills because the excessive renewable subsidies have allowed some households to dodge paying their share of network and operation costs.

      Economy 7 storage heaters are another possible example. If we had proper smart meters that is.

      E7 has operated for fifty odd years without smart meters, it works with smart meters, so I don't see what your point is. Worth recalling that E7 only existed because there were no good energy storage options, and the government had built a shed-load of huge, inflexible coal power stations that had to keep running at a minimum load during the night. As government policies rush to promote EVs, the overnight demand will increase dramatically, and there won't be this magical period of really cheap overnight electricity.

      And one further thought about renewable heating. Peak heating demand is after dark on the coldest stillest winter nights, and renewables aren't going to help much. Storage would only really work if it were intra-seasonal, and in that case you only cycle the asset a handful of times a year, and that's hugely expensive (which is why nobody wants to invest in gas storage).

    5. Alan Brown Silver badge

      Re: Balls

      "As we get more and more renewables then there will soon be a time when cheap mains electricity can be used for space/water heating in domestic situations rather than gas or oil."

      1: The gas is going to run out sooner than you may think

      2 Oil is getting too expensive for heating

      3: Before both of these come to pass we're likely to see government pushes to decarbonise domestic heating.

      The problem is this:

      - Using electrical generation 2001-2005 as a base line.

      - An electric car fleet will use as much power as the base line.

      - Adding an electric commercial fleet will double that (if not more)

      - Decarbonising domestic and commercial heatingwill use at least as much power as the base line (possibly twice as much)

      - Decarbonising industrial processes (particularly steel, foundry and cementing processes) will easily use 3-4 times the baseline.

      - if you pave the country's rooftops with solarpanels and forget the 2 miles safety spacing around windmills (blades go over a mile if thrown) then renewables in the UK can on average slightly beat the baseline

      So, making up the difference is done..... how?

      Renewables are all well and good, but I don't see any magic unicorn farts making them able to produce more energy than is available to actually be extracted. There are limits to their capacity and you can't magically import "lots of energy" from over the seas either as submarine interconnectors are limited by physics to about 2GW apiece and a reasonable spacing apart.

      I know this is going to get a bunch of downvotes, but it's worth actually doing the fucking math instead of indulging in wishful thinking or we're going to be sitting around in the dark shivering our arses off in a few years. I for one don't want to have to put up with rolling power cuts with no gas or oil to make up the heating shortfall.

      Apart from the huge shoirtfall in overall supply the intermittent nature of renewables also means huge investment in things like Elon's South Australian battery bank (which should be mandatory for every wind/solar farm over 1MW nameplate generation capacity).

      Of course this isn't just a UK problem. Apart fro the energy shortfalls fascing developed countries, developing ones are looking at needing to increase their power generation capacity by factors of 20-60. the Chinese are still investing heavily in Molten Salt technology research and it's quite likely that they'll be selling packaged solutions worldwide before anyone else.

      The entire world's economy moves on cheap energy - the country which controls or supplies it will be the one which dominates in future. How's your Mandarin?

  9. dvd

    "The energy grid isn't set up to store energy, explained Henry, associate professor of Mechanical Engineering at MIT, in an interview with The Register. "The whole grid is operated by predicting demand and dialing in supply," he said."

    Erm .... Cruachan? Ffestiniog? And a few dozen other pumped storage power stations worldwide? With even a few in the US, so he doesn't even have that excuse.

    1. Martin Gregorie

      And a few dozen other pumped storage power stations worldwide?

      Sure they exist - where the landscape topology and underlying geology make it practical to build high and low ponds that are leak-free and unlikely to be harmed by earthquakes - but there aren't many suitable places to build them and the total energy they store is tiny by comparison with the energy flows in the electricity grid they're attached to. IOW the pumped storage capacity is too small to make much contribution to balancing energy supply against demand.

      OTOH including a suitably sized storage battery (using silicon, molten salt, flow technology or whatever) as an integral part of a renewable energy farm seems like a good idea, especially if national grids are redesigned to act more like a set of interconnected regional grids. Co-location makes the losses due to high energy flows between energy sources and storage batteries easier to minimise because the links would be very short.

      1. dvd

        Oh, absolutely it's a good idea.

        I'm more taking exception to the idea that the technology doesn't exist.

    2. John 48

      Nice though they are....

      We (in the uk) only have approx 27GWh of pumped storage added all together - which sounds ok, til you realise our base load could use that in an hour, and peak in 40 mins. The killer however is the maximum power output from them all running full chat is around 2.4GW - so enough to cope with the short term loss of a one major generator, or to balance out some demand during the day, but not enough to keep the lights on longer term even if you have vast generating reserves to allow more storage.

      (currently cheap night time electricity is used to pump the water back uphill, but you can imagine if we also move significant amounts of space heating and transport over to electric power, that is not going to be available either!)

      1. Alan Brown Silver badge

        Re: Nice though they are....

        "We (in the uk) only have approx 27GWh of pumped storage added all together - which sounds ok, til you realise our base load could use that in an hour, and peak in 40 mins."

        They can keep the lights on long enough to bring up something else from spinning reserve and THAT'S what counts - and power would be found to pump back in "off" hours, as they're a critical resource for peak matching given the UK's dire lack of large hydro.

  10. Anonymous Coward
    Anonymous Coward

    The Greatest Challenge

    The greatest challenge to green energy is not science or technology. It is entrenched business models and those can only be overcome by financial pressure.

    1. bombastic bob Silver badge
      WTF?

      Re: The Greatest Challenge

      and here _I_ thought it was THE LAWS OF PHYSICS!!!

      1. ibmalone

        Re: The Greatest Challenge

        There's no law of physics that says we have to fill the atmosphere with carbon dioxide to get electricity. All the fossil fuels we're currently burning were originally derived from sunlight.

        1. Charles 9

          Re: The Greatest Challenge

          Then how did the carbon get from the Sun to the Earth, eh? Because I don't recall the Sun ever producing or emitting carbon. And under the laws of physics, the carbon doesn't appear spontaneously, either.

  11. Anonymous Coward
    Anonymous Coward

    Thorium Cycle Reactors

    These burn up over 98% of the fuel used, compared to around 2% maximum on current pressurised water reactors, and can use almost all normal nuclear waste with minimal processing and that includes depleted uranium. In fact, the fuel doesn't even need to be highly enriched so there is no danger of 'terrorists' stealing some to make a nuclear weapon. Estimates are that all the current nuclear waste created over the past 60-odd years could power Thorium cycle reactors for over 20,000 years.

    They are also inherently fail safe and cannot experience a meltdown due the design: when testing the prototype reactor they built in the US in the 80's they repeatedly cut all power to every system and it just heated up to it's design temperature, stabilised, then cooled down. No problems, no damage experienced, completely functional.

    It subsequently got canned due to politics and big business - if you build a PWR (which costs a LOT), you are committed to procuring all your fuel rods from the supplier of that reactor for the life of that reactor, and that isn't cheap when you also consider you are only actually using up to 2% of that fuel. There's no benefit for the industry that has grown up around building PWR's in moving to a design where they can't tie you into buying more fuel from those suppliers.

    Building a nuclear reactor that reuses existing nuclear waste which requires minimal reprocessing before use and then using up 98% of that fuel makes absolute sense, provided the will is there to pursue it.

    1. oral_suspension

      Re: Thorium Cycle Reactors

      All nuclear reactor designs are absolutely amazing. All of them will produce astonishing power outputs cheaply and cleanly with virtually no problems, until they are built.

      1. Jellied Eel Silver badge

        Re: Thorium Cycle Reactors

        All of them will produce astonishing power outputs cheaply and cleanly with virtually no problems, until they are built.

        Sure, there are FOAK costs involved. Or used to inflate costs (Hinkley isn't a FOAK design). One of the biggest problem/cost issues though are the endless objections by loony Greens who don't know the difference between nuclear power and bombs. They add a lot of arguably unneccessary costs for planning approvals, objections, judicial reviews etc etc. And are also happy with putting a heavy spin on the 'dangers'. So reactors may produce waste with a half-life of 100,000 years! Scary! Or much like a lump of granite. It's the stuff with a half-life of minutes that's fun.

        Sadly, greens have hijacked energy policy in the UK, Europe and US. Which is why we're not building reactors, and plenty of other countries are. They'll have cheap, reliable power and we won't. But for greens, they seem stuck with the idea that the Industrial Revolution and steam displacing wind power was a terrible idea, and going back to wind will somehow be different this time..

        Thorium and other reactor designs are especially upsetting if you point out they're good at recycling the radioactive waste the greens are so afraid of. Or just pointing out that a lot 'nuclear' waste comes from hospitals and isotopes used to treat patients.. And producing those isotopes is something that windmills and solar panels can't do.

        1. Justthefacts Silver badge

          Re: Thorium Cycle Reactors

          I have always thought the easy solution would be true citizen democracy ;)

          Have a referendum asking whether Britain should go nuclear or build out renewables. Maintain voting records, and saddle people with consequences of their chosen option.

          1) During Power shortages caused by variability of wind or solar, smart meters would blackout those who voted “renewable” until the dip subsided, performing demand management and protecting supplies for those who chose to value security of supply.

          Privatised Electricity companies can choose to build out storage systems, which will cost whatever they cost, and renewables folk can sign up to those packages if they like. I have no idea what the trade-off curve is between cost and reliability drop-out. But the renewables folk think it reasonable to impose this unquantifiable on everyone, so it must be Ok for themselves.

          2) Nuclear folk are required to buy third party insurance for the nuclear risks, including the supposedly unquantifiable (but actually rather accurately known) decommissioning cost. This is easily re-insurable (and indeed you can buy those corporate bonds right now), so there should be a competitive insurance market. Others will point out that I can’t guess very well what the insurance premium will be. But, since we already have nuclear baseload, and the consequences to our country will happen whether I like it or not, we all of us anyway currently end up paying that anyway, by taxes over time. So I can’t whinge.

          Under these conditions both religious factions can vote how they damn well please.

          My tribe is nuclear, so *we* get turkey with all the trimmings *every* Christmas, with million candlepower Christmas Tree lights. Children of Renewables parents hoping to be invited for Christmas can......return to the Middle Ages whence they came, while their sad, hungry eyes watch the windmill sails with trembling but ultimately futile hope that the wind will blow with just the right amount of puff to power both the shower and the oven.

          Merry Christmas one and all!

          1. ibmalone

            Re: Thorium Cycle Reactors

            Why not a mix? Why does everything have to be about the team you're on? Must be all A or all B! And then the solution MUST be set up to punish everyone who thought differently, so we they'll finally recognise that we're right and they're wrong. Chuck in some wind, maybe it wont cover demand 100% of the time, even with storage, but hey, it reduces the risk you're taking on nuclear, your exposure if supply drops there and your need to get uranium ore. Iceland smelts a lot of aluminium, why? Because they've got geothermal power and it makes economic sense, yet you get the impression from the more extreme edge of climate change denial that the desire to burn fossil fuels is at least partly driven by a perverse desire to make other people unhappy.

          2. Omgwtfbbqtime
            Boffin

            re: 2) Nuclear folk are required to buy third party insurance for the nuclear risks

            Nuclear Pools Limited

            Insurance as a levy of part of the electricity cost?

            Fair enough, count me in.

        2. Alan Brown Silver badge

          Re: Thorium Cycle Reactors

          "So reactors may produce waste with a half-life of 100,000 years! Scary! Or much like a lump of granite. "

          It's fun to pass them a lump of granite and ask them if they realise how radioactive it is.

          Or how much radiation they realise they're exposing themselves to when they fly

          etc.

      2. Keith Oborn

        Re: Thorium Cycle Reactors

        Thorium reactors have been built, but not for some time.

        Why? Because they don't produce tasty isotopes of elements like Plutonium, so the military/government gains no benefits, doesn't put in any investment--. Look at where all the fundamental money for Uranium fission technology came from.

        Add to that the reduced need for complex mining operations, and the near-elimination of all those juicy waste reprocessing, storage and decommissioning contracts, and it's no wonder the commercial nuclear operators aren't interested. No gravy train.

        I understand, though, that India and China are putting money into Thorium.

        1. ibmalone

          Re: Thorium Cycle Reactors

          I understand, though, that India and China are putting money into Thorium.

          Nothing really demonstrated yet sadly. The current approach is defence in depth, and why not? Wind is pretty well proven, it's not perfect, but neither is burning more and more fossil fuels until we finally run out or convincingly demonstrate global warming by flooding the world's financial centres (they tend to be in flood plains). Modern nuclear is okay, but expensive, and the PR battle was lost decades ago. Solar for heating is making quiet gains, PV is now practical. It'll be nice if a working thorium station is developed and lives up to its promise, but we've yet to see it. Hopefully it'll only be interim to fusion though, the joke is it's always ten years off, but it used to be that it was always twenty years off, and before that always thirty years off; we do seem to be converging, just slower than hoped. Other than that, fill the deserts with PV (they're silicon already anyway) and use the power to make something transportable.

        2. Alan Brown Silver badge

          Re: Thorium Cycle Reactors

          "Why? Because they don't produce tasty isotopes of elements like Plutonium"

          Strawman.

          Very little plutonium has ever been weaponised from reprocessed civil reactors (other than to prove it's possible) as it's a mix of isotopes and some of them are "hot" enough to make any bombs "fizzle" instead of "boom" (paradoxically, nuclear weapons don't work well if the source materials are _too_ radioactive). Virtually all reprocessed plutonium gets mixed into civil fuel rods if its ever reused at all.

          The weaponisation of uranium in the civil nuclear cycle happens when the uranium is enriched - a long time before any of it it ever sees the inside of a civil nuclear reactor.

          Most is enriched to 3% and sold on to civil plants.

          SOME is enriched well past 3% (usually to 50% or so) and used in military reactors to produce plutonium or in aircraft carrier/submarine reactors (which need to be smaller)

          SOME of the leftover U238 ("depleted uranium") is used to make bullets.

          U238 is an essential component of Teller-Ulam thermonuclear weapons (That's "hydrogen bombs" to you and me) - the casings are made out of it and MOST U238 gets used for this purpose.

          Some U238 is onsold for paint pigment (it's yellow)

          THIS is why the USA regards the costs of uranium enrichment for the civil nuclear program as a classified military secret - the power lines into the facilities in Tennessee show it's a huge energy consumer though.

          This is why it's operated as a military project under the DOE, not a civilian one.

          This is why enriching uranium anywhere in the world (even for civil reactors) is regarded as weapons manufacture - not because of the uranium, but because it can be used to make plutonium and THAT is what's used to make bombs.(U235 bombs are extremely expensive and require 95% enriched uranium)

          The military hate Thorium cycle because it's extremely difficult to weaponise. The plutonium that's produced is an even more bastard mix of isotopes than in a uranium reactor and totally unusable (one of the Pu isotopes ia a very strong gamma emitter too). The Uranium isotopes are also a big mix.

          Yes, you can extract U233 if you use a dual blanket system - but you'll pay for that with a massive reduction in power output, so it's noticeable - and the simple way to prevent this is to use a single fuel design.

          This is why the "establishment" is so firmly wedded to using Uranium, despite its manifest UNsuitability for civil nuclear power generation - and will continue to be as long as there's a military mindset in charge. The cold war never really ended. The military machines got so large that their tail started wagging the dogs (countries) they were attached to a long time ago and they've been desperately trying to find an enemy (any enemy) to point at and distract the civilian population with for the last 25-30 years.

          The public simply hate nuclear thanks to 70 years of scary stories,. "4 legs goood 2 legs baaaaad"

      3. Cynic_999

        Re: Thorium Cycle Reactors

        "

        All nuclear reactor designs are absolutely amazing. All of them will produce astonishing power outputs cheaply and cleanly with virtually no problems, until they are built.

        "

        The same is far more true of so-called "renewable" energy sources.

  12. RobThBay

    I'm surprised that no one mentioned how far ahead Apple is in this technology.

    They've had sun in your hand (or pants pocket) for years.

    :)

  13. John Smith 19 Gold badge
    Unhappy

    Hmm. Reminds me of the SolChem work of the US NRL in the early 80's.

    Solar heated catalysts --> shifts balance of chemical mixture --> released by reverse catalysts into tank of aerosol cans filled with salt eutectic (cans keep the mix water vapor free and partition massive volume change as it goes solid --> liquid).

    The US Navy never wanted to be reliant on foreign oil for its fleet ever again.

    Then Regan got elected, oil was cheap and the research got shut down.

    SolChem became an old cover story in PopSci, where I found it looking through the stacks one day.

    1. Chemist

      Re: Hmm. Reminds me of the SolChem work of the US NRL in the early 80's.

      "reverse catalysts "

      Do you have a ref. for this. What in deity's name is a 'reverse catalyst' ??

      1. John Smith 19 Gold badge
        Unhappy

        "Do you have a ref. for this. What in deity's name is a 'reverse catalyst' ??"

        What I meant was a catalyst that reverses the original solar heated process, giving up latent heat in the process.

        The idea was to avoid higher temperatures and move more energy by increasing the flow rate of the chemicals, which sounded a pretty good idea to me.

        IIRC candidate reactions were N2/H2/NH3 and SO2/O2/OO3

        Relevant reports would be from the DTIC DoD search engine, although I'm not sure any of it is in PDF's. .

        1. Chemist

          Re: "Do you have a ref. for this. What in deity's name is a 'reverse catalyst' ??"

          Let me be clear on this, at least for others. A catalyst only increases reaction rates (in either direction equally ) by lowering the activation energy. The system will reach its tthermodynamic equilibrium ( at the temp/pressure it's under) faster. It's a kinetic effect.

    2. Charles 9

      Re: Hmm. Reminds me of the SolChem work of the US NRL in the early 80's.

      "The US Navy never wanted to be reliant on foreign oil for its fleet ever again.

      Then Regan got elected, oil was cheap and the research got shut down."

      Hmm? Last I checked, the project is still ongoing, as carriers and jet fuel have always been a weak link.

  14. Loud Speaker

    Sun?

    I was expecting to hear about a huge mass of "Enterprise servers" fused together in a box. (Preferably with Larry Ellison in the same box).

    1. Korev Silver badge
      Thumb Up

      Re: Sun?

      I remember the "datacentre in a container" idea.

    2. Evil Auditor Silver badge

      Re: Sun?

      So far I was only aware of Sun in a pizza-box. Still got one of those in my attic. That box is rather an energy sink than a storage though.

  15. Brad Ackerman
    Boffin

    I was expecting a Galaxy Death Note 7 joke somewhere in this article.

  16. Tomato42
    Alien

    Actual efficiency?

    "While converting heat to electricity is inefficient, that loss can be overcome by the potential cost savings – storing heat is 50x to 100x cheaper than storing electricity, the researchers say."

    actual numbers for that? missing. wonder why...

    thermal solar already struggles to be competitive with PV and while electric heating is close to 100% efficient, the extraction would have to be an order of magnitude better than thermal solar

  17. Spherical Cow Silver badge

    Pendant's Corner

    "They dig a big hole and fill it with concrete..."

    After the hole has been filled with concrete, where does the silicon go?

    1. Anonymous Coward
      Anonymous Coward

      Re: Pendant's Corner

      So you're a pendant, are you?

      Something hanging, like an ornament or light fitting?

      1. Spherical Cow Silver badge

        Re: Pendant's Corner

        Yep!

        Fucking autocorrect.

  18. Anonymous Coward
    Anonymous Coward

    If

    If they can put a sun in a box.

    Maybe they can put a brain in the POTUS?

  19. Milton

    More

    Interesting start but the article is shallow as a puddle and left me wondering "Why silicon?". I did a search and found a decent brief for the layman here: New Atlas 'MIT Sun-in-a-Box' (no, I'd never heard of the site before either).

    Seems like silicon is good because it's cheap, abundant, has a high and stable melting point and has the self-sealing attribute mentioned in the article, forming a carbide and preventing further corrosion. Salt, of course, becomes bastardly corrosive at anywhere near these temperatures, ISTR Soviets (?) had issues in early attempts to use molten salt in reactors (was it for subs?). The NA article also says a bit about extracting energy using the light radiated from molten silicon to energise photovoltaics instead of what you'd expect (a steam turbine). That's intriguing, as is the possibility that this system may have very few moving parts: the attraction isn't just in presumed (storage:recovery) efficiency ratios—it may be also be in low maintenance costs, long life time and reliability. It sounds like something you could mass-produce remarkably cheaply and, if located sensibly, would be safe even if if it failed in Spectacular Mode.

    We're used to a 'spiffing wheeze' every week in this game, but this one does tick a lot of boxes ....

    1. Charles 9

      Re: More

      I would think energy independence would've been a great political tool, ESPECIALLY during the Cold War (the old "You can't starve us out" argument), and it can still apply today to relieve realpolitik pressures.

  20. Cuddles

    "which have been known to burst into flames"

    The problem with energy storage is that it involves storing energy. If the storage system fails in some way, that energy will inevitably be released. Sure, lithium-ion batteries can catch fire when that happens. But look at the results when a dam bursts, a big flywheel gets loose, or a coal mine catches fire. When your goal is to compress as much energy as you can into the smallest volume possible, the results of suddenly dumping it all into the local environment are never going to be pretty.

  21. Anonymous Coward
    Anonymous Coward

    "While converting heat to electricity is inefficient..."

    I don't get this obsession with using heat as the primary source of electricity generation. We're not in the 19th century any more! A nuclear power station is really just an enormously complex steam engine ... with much more dangerous waste products.

    There are much more efficient ways of generating electricity, for example using kinetic energy from all manner of sources. Solar isn't that great, but its efficiency is improving all the time.

    One of the main things we need to develop urgently is a smart grid, which is designed around fluctuating sources. Only then would we be geared up to truly renewable power sources of the future. Until then we are stuck in the 20th century.

    1. ibmalone

      The laws of thermodynamics tend to apply whatever mechanism you use though. Converting between types of energy often ends up inefficient.

    2. Cynic_999

      "

      A nuclear power station is really just an enormously complex steam engine ... with much more dangerous waste products.

      "

      Wrong. The waste products of nuclear power stations are a darn sight safer and more easily managed than the waste products of coal-fired power stations.

      1. Charles 9

        Please elaborate.

  22. wiggers

    Government funding

    Presumably because no one else was daft enough to invest in it!

  23. Christian Berger

    Yeah but Lithium Ion Batteries are among the most expensive

    A fairer comparision would compare it to cheap batteries like lead acid.

  24. Andy 97

    Liquid air?

    I think this could be more of a better solution (unless you own shares in silicone)

    http://energystorage.org/energy-storage/technologies/liquid-air-energy-storage-laes

  25. JeffyPoooh
    Pint

    "...costs will need to be about $50 per kWh..."

    Assuming such systems could be used at least 1000 times, you'd think that $0.05 per kilowatt-hour (each use) would be about an order of magnitude more generous than required.

    If 10,000 usages lifetime, even more so...

    So his numbers don't seem reasonable.

  26. Unicornpiss
    Coat

    Why molten silicon..

    ..Anyone who has burnt their mouth on a baked potato knows that they stay ridiculously hot long past what was expected.. Just need a pump to flow the molten butter through a heat exchanger and, well... never mind.

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