Liquid Tin Could Be The Key To Cheap, Plentiful Grid Storage

Once expensive and difficult to implement, renewable energy solutions like wind and solar are now often the cheapest options available for generating electricity for the grid. However, there are still some issues around the non-continuous supply from these sources, with grid storage becoming a key technology to keep the lights on around the clock.

In the quest for cost-effective grid storage, a new player has entered the arena with a bold claim: a thermal battery technology that’s not only more than 10 times cheaper than lithium-ion batteries, but also a standout in efficiency compared to traditional thermal battery designs. Fourth Power is making waves with its “sun in a box” energy storage technology, and aims to prove its capabilities with an ambitious 1-MWh prototype.

Hot Stuff

Simple heating elements turn electricity into heat, putting it into liquid tin that then heats large graphite blocks. Credit: Fourth Power, Vimeo screenshot

The principle behind Fourth Power’s technology is deceptively simple: when there’s excess renewable energy available, use it to heat something up. The electrical energy is thus converted and stored as heat, with the idea being to convert it back to electricity when needed, such as at night time or when the wind isn’t blowing. This concept isn’t entirely new; other companies have explored doing this with everything from bricks to molten salt. Fourth Power’s approach involves heating large blocks of graphite to extremely high temperatures — as high as 2,500 °C (4,530 °F). Naturally, the hotter you go, the more energy you can store. Where the company’s concept gets interesting is how it plans to recover the heat energy and turn it back into electricity.

Of course, operating any sort of storage system at such high temperatures takes some serious engineering. At the heart of Fourth Power’s system lies a unique innovation, in that it uses liquid tin as a working fluid to move heat around. It required the development of a liquid tin pump capable of operating at temperatures exceeding 1,000 °C (1,800 °F). Most pumps built using metallic components would simply see their components melt and fail under such extreme conditions. Instead, the pump uses a ceramic design. Developed by Fourth Power founder Dr. Asegun Henry, it can withstand temperatures of many thousands of degrees Celsius. Indeed, that’s important, as the liquid tin in the system is at 2,400 C at its hottest, and cools down to 1,900 C at the coldest part of the system.

Indeed, the pump actually holds a Guinness World Record for the feat, and was of great technical note for this achievement. This pump is crucial for moving the superheated liquid tin around the system, transferring heat efficiently from the heating elements to the graphite blocks and back. It’s key to the whole system, as thermal energy systems are generally most efficient when operating at the highest possible temperatures. Thus, by being able to pump liquid tin at such high temperatures, it’s possible to transfer energy into and out of the graphite blocks more efficiently than using a more typical working fluid at lower temperatures.

Thin graphite pipes carrying liquid tin emit light when they become hot. This is then captured by special thermophotovoltaic (TPV) cells inserted in the middle of the pipes, which turn the light into electricity. Inserting and removing the TPV cells can vary their power output, allowing the system to quickly respond to demand spikes or troughs. Credit: Fourth Power, Vimeo screenshot


Here’s What is New

The energy recovery process itself is quite unlike most traditional heat storage concepts. When the grid needs energy, liquid tin is pumped around the hot graphite blocks, which heats it up to 2,400 C. The tin is then run through thin graphite tubes, which glow white-hot as it passes through. The light emitted is then turned into electricity by thermophotovoltaic (TPV) cells. They’re essentially similar to solar cells, but they’re fine-tuned to most efficiently generate electricity from the wavelengths output by the graphite in this specific application. Through development, these cells have reached efficiency levels competitive with steam turbines when it comes to turning heat into electricity. The cells are designed to harvest the most high-energy wavelengths of light output by the hot graphite pipes, while reflecting back the rest so that the liquid tin remains as hot as possible. This part of the concept actually gives the company its “Fourth Power” name. That’s because as per Stefan-Boltzmann’s Law, the output of radiant energy from a black body is directly proportional to the fourth power of the material’s absolute temperature.

The thermal battery is intended to be able to respond quickly to the grid, ramping up delivery in a matter of seconds to cover spikes in demand. By virtue of being based on flowing tin, it’s not going to be quite as fast as battery solutions, but still quicker than firing up large turbine-based generation. Currently at 41%, the company is targeting round-trip energy efficiency of approximately 50%. It’s important to note that is a much lower figure than traditional solutions like pumped hydro, along with lithium battery arrays like the Hornsdale Power Reserve, which typically sit around 80%.

Thermophotovoltaic cells pick up light energy emitted by thin graphite pipes, which glow white-hot when liquid tin is passed through them. It’s an unusual way of turning heat back into electricity, but it’s comparable in efficiency to a good steam turbine. Credit: MIT

However, it’s balanced out by the system’s low-cost materials, which Fourth Power says is on the order of ten times cheaper than comparable lithium battery storage solutions. Much of that is down to the materials involved, with graphite and tin being abundant and cheap compared to the fancy materials required to fabricate high-density lithium-ion batteries. The cost per kilowatt-hour of stored and returned energy is projected to be less than $25, compared to a figure of $330 that the company quotes for a lithium battery setup. This price advantage could make the technology a potentially disruptive force in the energy storage market.

It’s not a perfect solution to all grid storage questions. The company touts its use for both short and long duration storage, which it can achieve. However, there are losses involved with heat storage over longer time periods, as the system tends to lose heat and cool down over time without additional energy input. It’s also potentially mechanically more complex, and currently, largely unproven. However, if the concept works at prototype scale, that should demonstrate whether it can be a useful tool nonetheless.

Current plans involve the development of a 1-MWh prototype facility to be constructed near Boston, which should be up and running in 2026. That’s just a pilot-level installation, as today, grid battery storage solutions are capable of storing hundreds of megawatt-hours of power, and spitting it out in short order, too. If proven practical, full-scale commercial installations could be a thing in the years following, but we wouldn’t be expecting to raise a glass to completion of a major tin-based grid storage plant before the decade is out.

143 thoughts on “Liquid Tin Could Be The Key To Cheap, Plentiful Grid Storage

      1. It’s not that difficult.

        If you have a number X, then X times more means multiplying by X^(+1) and X times less means multiplying by X^(-1). Plus is more, minus is less. Simple.

        1. Though of course you have to mind that “X times more n” is always n + nX because you specify “more”, which includes the original amount. So if you start with one apple and you get two times more, you have three apples, which is plain and obvious.

          Likewise, “X times less” means n – n/X because you subtract from the original amount. Therefore, “Ten times less” means 90% of the original amount. Obviously.

          So you have to mind what you say. 10 times cheaper is actually a 10% discount, because cheaper is less and therefore you take the negative exponent, and you subtract because you’re comparing to the original amount. This is perfectly sensible and reasonable, and there’s no reason why we shouldn’t use such expressions – just that we should mind what we mean when we say them.

          1. If “n times more ? than x” means x+n*x
            then “n times less ? than x” would logically mean x-n*x
            At least in my logic but I guess it’s a bit like the pictures were different people see two faces or on vase.

            Interpreting “n times less” as meaning “multiplying with 1/n” sounds to me like explaining this bad idiom after the fact. As in: When people use this phrase but actually mean “one n-th” = 1/n let’s invent a mathematical interpretation of those words to fit and divide instead of multiply…
            Lucky use we can use “^-1” so it *fits* for the price of not being able to explain this to most people anymore.

            I mean seriously?
            “n times” literally = n*
            “more” = +
            “less” = –

            “It’s not that difficult.” It just means the phrase almost never makes sense / is used wrong.

            That being said, English is not my mothers tongue and I think direct translations of the phrases “n times more/less” are almost never used (“more” maybe sometimes but almost never “less”).

          2. >then “n times less ? than x” would logically mean x-n*x

            Of course not, because we’ve already established the meaning of “N times less”.

            It can only mean division, because the only way to get “less” by multiplication alone is to take the reciprocal. Now, getting “less than” involves a comparison to a second number, which is where the subtraction comes from. We have “N times less” which is a division, and we take that away from X, so it is “N times less than X”. That’s the only coherent way to read it, in order to maintain both cases.

            Don’t you agree?

        2. This^ .. thank god I’m not the only one.

          Not sure when mathematically incorrect phrasing like “10 x larger” started becoming popular, but it drives me crazy.

          It’c comforting to know that it’s not just me ..

          1. That’s because language is too ambiguous to be used for mathematical expression. Whatever you do, there’s always ambiguity (even if you use a % case, like it’s 20% cheaper, most of the people get it wrong). The only viable option is to give raw numbers: the storage of 1MWh is expected to be $25 compared to $330 with lithium. There’s no ambiguity and let the people make the computation if they want to.

      2. Because fractions are still VERY useful because they show a relationship in an intuitive way.

        7/16 can be more useful than 0.4375

        It won’t always be. But it CAN be.

        13/27 is much more useful when talking about 13 of the 27 bolts in a drawer.

    1. Yes we take the “cheapness quotient” and multiply that by ten, obviously. The figure describes how chintzy it is, not the price. You can scrape the finish right off with your thumbnail.

    2. Unfortunately it is not just English language which has that same moronic idiom.

      No wonder people don’t know basic math.

      Please hackaday, even if it says that on the news release, how about you fix that in your articles? This grinds my gears.

      1. I’m not so sure this is idiomatic English. I’m a native speaker, and in my book, this is hardly a “natural expression”.

        My impression is that sloppy phrasing like, “10 x larger”, in lieu of a cleaner, more precise phrasing like, “10 x as large”, is something that has crept into usage only recently.

        I pray it will creep back out even faster than it crept in .. because it’s definitely one of my more intense “bad English” peeves.

        The phrase, “10 x cheaper” used in the article is next level sloppiness. “1/10th the cost”, “90% less expensive” .. whatever .. but “10 x cheaper” .. good lord ..

    3. hear hear! just garbage language usage. takes something very very simple and makes it confusing but you get to say something more exciting : “TEN TIMES MORE!!!!!1!” is more emotional than “ONE TENTH!!!” lol. it’s a red flag showing the writer does not respect the reader

    4. If B is 10 times cheaper than A, than A is 10 times more expensive than B. It’s division instead of multiplication. I don’t see what the problem is. Everyone knows what it means. Though I prefer percentages or other fractions with the same denominator since it’s hard to compare unlike fractions in your head.

      1. It’s not that simple.

        If A is 10 times more expensive than B and B costs $10, then A must cost $10 x 10 = $100 more than $10, which by simple addition is $110. Therefore A costs $110 and B costs $10.

        If we should claim that “B is 10 times cheaper than A”, a simple division would imply that A = 10B which isn’t true, because we know by the previous calculation that A = 11B, so we have a contradiction. The two expressions aren’t reciprocal.

        1. I see your point. The word “more” implies addition.
          If B is 10 times cheaper than A, than A is 10 times costlier than B. Would this be correct?

          In Dutch we can say the equivalent of “x times as expensive as B” so I wasn’t aware of the difference.

      2. Except for “times” = multiply and “times” = divide is slightly contradictory.

        I mean one can see it as working because it’s language but then we wouldn’t have this “divide” ;-) over the “n times less” phrase.

          1. Ha, took me second to recognize “n-fold” (what does “folding” got do with this discussion…). ;-)

            Yeah, okay it kinda is but it’s not used in math (classes, lectures, etc) for multiplying, is it? I don’t know – never had a math class/lecture in English.

        1. Not at all. “Times” is just multiplication.

          “Times less” is a division, because the only way to get less by multiplying is by taking the reciprocal of the number, in other words by dividing, or multiplying by X^(-1).

          But then you add another modifier, “times less than”, which is yet a different thing. The “than” term is obviously not a multiplication, but it is relative to a second number and a reduction from it. As above, “X times less than Y” therefore and actually means Y – Y/X

          This way all three expressions, “times”, “times less/more”, and “times less/more than” maintain coherent meaning without contradictions, naturally and logically. Whether you agree to use them in such ways is your own business.

  1. I wonder if it would be cost effective to use off-peak power to “top off” the batteries at night or during the early morning hours. There are companies that do that in areas with higher differences between off and on-peak power rates, called Energy Arbitrage. They buy “low” during off-peak and sell “high” during on-peak.

    I saw a concept a while back that used a block of asphalt with an ammonia loop inside it that then heated a water loop. The whole thing was set up to drive a low pressure Kalina Cycle power plant. The idea was that direct sunlight heated asphalt was cheaper and easier to maintain that solar mirrors. It could be set up in more austere environments where photovoltaic panels were harder to come by.

    I wonder if they could use something similar to bolster or augment the liquid tin graphite concept in areas with hotter weather most of the year.

    1. “The cost per kilowatt-hour of stored and returned energy is projected to be less than $25, ”
      Hopefully it is megawatt-hour or it would be cheaper with a baconfired powerplant as backup.

          1. How do you figure? $25 for 800 kWh would be a little over 3 cents per kWh, which is tiny.

            I looked at a few ERCOT real-time-price graphs just now; if the third party providing them isn’t wrong, the prices tend to vary quite a bit. Over the course of a month it looks like you have some time at negative price and a decent amount of time at a steady baseline, but there’s also times where it spikes upwards, and for several hours before and after the spike, the price is elevated quite a bit over the baseline. If the graphs and the headlines are right, the electricity price on the backend can get so high that you could make your $25 back in a single day if you sold at the peak. That sounds wrong, but I do find myself convinced that there is plenty of room for a 50% efficient massive setup just to cut off the daily peak prices even if it had to pay current baseline prices to do it.

          2. Power is sold at multiple different time scales with the bulk of power sold a day ahead of the actual demand. This power goes at wholesale prices close to the cost of production. Then there’s the spot market which deals with the hour and minute variations, and on that market the price can swing up and down by crazy amounts.

            It’s not unheard of to have $2000/MWh prices to patch up that little bit of power that can’t be produced otherwise, but the overall system price is diluted down by the sales contracts were made the day before. The greater the portion of the power that can be sold day-ahead, the less volatile the price becomes despite the high cost of the “margins”.

            These battery systems make profit by playing on the minute market, where they can sometimes sell at a hundred times higher than what they bought.

          3. The trouble with the day-ahead market, especially in northern Europe at the moment, is that enough of the power capacity has either been reserved by law for renewable power, or not enough other generators have been built to meet growing demand, such that the conventional power plants can no longer supply the full demand when the renewables aren’t operating.

            So there’s this persistent shortfall that occurs especially at this time of the year when the temperatures fall and the winds die down simultaneously, and the sun is obviously not up, so the whole system price goes up to la-la-land and people are cheaper off burning candles and cooking their foods on sticks while the power utilities scramble to start diesel generators.

            Quite literally. This is not a joke. This is happening. Last week power prices peaked well over €2.50/kWh in the Nord Pool.

          4. @Spaceminions Yes, it is 3 cents. That 1kWh of capacity has to be used 800 times with no addition cost to pay for the installation. It seems obvious that with operating costs and maintenance and personnel (and delivery cost?) it is much more. To be fair, this is hydro-power and I have no idea how it works out with original cost of a dam and all the equipment and overhead, but the continuous MW’s with no fuel costs on 50 year old generators and such must pencil out pretty good.

            I wonder about the cost with these new small modular reactors being bought by several countries.

          5. “$25 for 800 kWh would be a little over 3 cents per kWh, which is tiny. ”

            PLUS TAXES making $47.66.

            It’s for “The Climate™” Welcome to MARXISM.

          6. @charles, well hydro is the keyword there – if you’ve got that, your area is one of the minority that doesn’t necessarily need this, given it’s got its own storage buffer and hydro is already a nice power source. Some of us rely on coal still.

            @dude, Oh yeah, that’s how they do it. I forgot power works that way; I’m used to looking at other stuff where everyone looks at the live price, even if they use contracts and such. Well anyway, plenty of variation on the short term for someone to move into with whatever they can.

          7. About 70% of the power market is currently sold day-ahead or even longer power purchasing agreements, and the other 30% is traded by the hour or minute.

            The problem right now is that nobody wants to build power reserves to deal with the remaining 30%. It doesn’t matter if it’s batteries or gas turbines and diesel generators, it still costs extra money. Average consumer prices must go up in order to deal with the intermittent inputs from renewable energy, so instead the prices are allowed to swing like crazy and people have to jump hoops between negative power prices and burning candles when it goes up to dollars per kilowatt-hour.

            Ironically, not even the industry wants this situation, because even though you could do things like make hydrogen out of “free” electricity, the equipment to deal with intermittent inputs cost more money and only operate a fraction of the time, so the capital efficiency is poor: you get less output for the money compared to having moderately priced electricity available all the time.

          1. It’s dollars per kWh of capacity. That’s how batteries are compared. It’s a meaningless number, because it doesn’t account for service life and energy throughput, and energy losses. Whatever the number, it is not true.

            For example, the minimum cost for lithium battery storage assumes maximum throughput – maximum cycles through the battery within its calendar lifespan. If this is not the case, then the cost of storage goes up because the capacity is not optimally utilized.

            If the battery is fully cycled every day, it may reach that optimum, but if it’s cycled weekly or monthly then the cells will yield less energy throughput per dollar and the cost goes up by a factor of 7-30x compared to the first case.

        1. Yes. It’s usually given as the cost to manufacture a kWh of battery cells. Anyone can give any fudge factor to “account” for the rest of the system on top.

          Modern NCA lithium cells should cost something like $150/kWh. Safer and less energy dense LiFePO4 etc. cells are roughly double that. Prices vary between whether you want to buy proper cells, or some “Happy Power Lucky Fast” batteries that might be anything.

      1. Of course I can’t find the figures now that I want to reference them, but the last time I looked it up the average difference between on and off peak Megawatt hour rates in Texas was right at $25 for the year. That includes the shifts in the demands as seasons change.

        I know a few of the green energy wind and solar sites have peak load balancing battery banks that let them sell to the grid when demand outstrips their production. They can also top them off for “free” when demand drops off.

        I know when Bush was still governor the state put in more green energy projects than anyone else at the time. I think Kansas is on their way to out pace the country for solar arrays next year. Regardless of the state, we’re going to need flexible storage across the national grids if we want to make the most out of renewable energy for peak demand during cloudy/no wind days. I sincerely hope they can make this project work. We need options other than lithium.

      2. Lets look at energy conversions.

        Electricity to heat.
        Heat to light.
        Light to electricity.

        With a peak solar cell efficiency being around 44% you would be lucky if this thing returns 10% of the energy stored in it.

        1. Resistance heating is very efficient in terms of converting electricity to heat essentially 100%. So if the thermoelectric panels are 41% efficient in converting the infrared/ visible light being emitted and losses to the environment are negligible then you get good efficiency.

          1. So the most you could ever get back is 41% of the energy you put in. This is miserable for an energy storage system. Also the photoelectric effect doesn’t work well with long wavelengths because they have a lower energy level. An efficiency claim of 41% os very dubious at best.

        2. Not only are you making up figures, but they’re figures that were given already. The whole stated advantage of these TPV converters is because they figured out how to emit the right wavelengths for their cells, as well as reflect the wrong wavelengths back to the emitter. That means a greater fraction of the photons turn into electricity and fewer turn into heat on the cell. The linked page talks about multiple bandgaps, mirrors, high temperature, etc as ways they do it.

    2. With an efficiency of 41%, it means you could only win something if the difference in on-peak and off-peak price is higher than that (very unlikely). And this is even without including maintenance cost.

      So, no, it won’t work for this case (even at 50% efficiency). Only a close to 100% efficient storage would worth it.

      1. No, it’s likely. It’s already true on the Texas markets, looks like, and I don’t know but I’d imagine many others too depending what kind of producers there are. It’s especially true on the short term markets, sometimes on day-ahead too, but as a battery, you could buy and sell on whichever makes you the most money so that’s enough.

        1. No it is not worth it.
          Its cheaper to just generate more electricity by some other means.

          Also Fourier’s Law has something to say about the heat loss encountered with storage at extremely high temperatures. Something that is very important with a grid level storage device that requires super high temps to work.

  2. > Indeed, the pump actually holds a Guinness World Record for the feat, …

    Not an immediate disqualifier but a bad *omen* nonetheless.
    Developing such a pump? – Awesome!
    Paying money to the terrible GWR to get in their *book*? – For what? Non-scientific publicity for gullible *idiots* instead of relevant industries???

    GWR has been collecting money from dictators, autocrats, regimes and whatnot for years if not decades now for ridiculous “world records” – eg.

    > Much of that is down to the materials involved, with graphite and tin being abundant and cheap
    How much “goes down” for the TPV celss?

  3. Tin isn’t actually all that abundant. It’s a conflict mineral, and most of it comes from China.

    Lithium is actually at least 10 times more abundant in the earth’s crust than tin is. If you’re going to start filling up power stations with liquid tin, you’ll quickly exhaust the world market and the price goes through the roof.

      1. Every darn thing that’s come out in the last 30 years uses some kind of rare/expensive/exotic/irreplaceable material. Tin really is surprisingly expensive and getting more so.

        Can’t we can’t make anything useful out of cat urine?

    1. World tin mine reserves (tonnes, 2011)[1]

      China….. 1,500,000
      Malaysia…. 250,000
      Peru…… 310,000
      Indonesia….. 800,000
      Brazil….. 590,000
      Bolivia….. 400,000
      Russia….. 350,000
      Australia…. 180,000
      Thailand…. 180,000
      Other…. 180,000
      Total…. 4,800,000

      So China DOMINATES! And don’t forget, 10% kicks back to the Big Guy.

      1. Tin – Occurrence

  4. Solder fountains pump tin around with no moving part (except for the tin) at all. They work by conducting current though the tin while it is in a magnetic field. It’s a quite interesting pump design, but I don’t know if it’s scalable to something like this.

  5. Maybe instead of (as well as) graphite blocks, some phase-change materials would store heat even more effectively/densely? You could have a range of vats (in dewer vessels) that melt at different temperatures.
    Then pipe the tin through it to heat up/get the heat back.
    E.g. ZnS, ZnO, Al2O3, CaO. Each vat as it melts would take up a big chunk of energy. And the materials are plentiful.

  6. It may be cheaper, but it’s still horribly inefficient. People are only interested because it uses “free” renewable energy. The problem is that those renewables are not at all “free” (in the “free beer” sense). On-shore wind is about $34 per MWh and utility scale solar LCOE is about $33 per kWh. So, not only not free, but more expensive than many other options. This doesn’t count environmental costs, of course, but the environmental cost of a ton of tin is not zero.

    This is an attempt to smooth out the unreliability of renewables, but I doubt that most locales would install enough capacity to really do the trick. Here in Texas, in winter, it’s not unusual for winter conditions to knock out solar for four or five days at a time, which would require a hell of a lot of storage. Wind is no better. You wouldn’t be installing enough battery back up to take you through a bad day, but *several* bad days (unless you accept blackouts). Not only that, but due to the 50% efficiency, you would need *double* the back up capacity of your renewable sources.

    Nuclear is the only real option from an engineering standpoint. Suck it up and deal with it.

    1. It doesn’t even have to last days to help. Just shifting tons of power from the midday supply peak to the evening demand peak most days would be helpful.

      I’m in Texas too, and while it’s a big state with a lot of different climates, it’d work well in my area. The only reason my February and August power consumption are similar is that I have incredibly inefficient heating – not only the house, but also multiple portable heaters to protect some of the plumbing not adequately protected by pipe heat tape alone. Unfortunately using resistive heat instead of fuel or heat pumps, especially with a lot of air leaks, consumes a lot of juice. If I can stop needing to do that, it’ll go down a lot and a few chilly cloudy days wouldn’t be the end of the world. And in August I’d only need the maximum energy on the same day as we got the maximum sun, because that’s when we need the most air conditioning.

      Plus, what if they could fall back on using fuel for the heat, at a similar efficiency to the old conventional turbines but with better ability to ramp up and down? It’d be nice to shut the coal plants down finally. And it’d help let other things ramp up and down gently, maybe including nuclear, while being affordable and simple enough to actually DO it, and without using up batteries that could have gone into a portable device or car.

        1. That’s true, but of course many of the existing lines couldn’t use that, and the wellhouse is another thing. Things here were poorly designed cold-wise. Sometime I’ll get at least the faucets running partially off pex.

          I hadn’t seen the internal heat, I’ll have to look at that soon. Thanks.

      1. Thing is, when the system loses over half of the energy you put in, the output costs at least twice the input, and the system can’t operate unless the power prices at least double between different times of day. Realistically speaking, the system price should swing by a factor of 4-5 before any of these battery schemes start to make ends meet.

        So here’s the kicker: if they actually manage to level off the demand curve, the price difference vanishes. Low prices go up and high prices go down. In other words, the battery would eat its own economic raison d’etre.

        That’s why they will never build enough of them to matter EXCEPT if they come up with yet another subsidy to make it happen, OR the power prices remain so volatile forever that batteries will always make sense. In other words, that the grid should remain under-supplied and unreliable.

        1. Well of course you would not drive yourself out of business; but that applies to ANY business, not just green ones. You don’t waste your time on oil wells that produce less than they’re worth, and you hate to sell oil when the price drops too far or goes negative. Same with this – the price difference would stall out at a new, smaller value, as enabled by the development. Certainly, it’d need to vary at least 2x, maybe more as you said, though not *that* much more I would think.

          Currently, at least on the Texas grid, the spikes seem to be *already* plenty high enough and frequent enough that you could probably operate a majority of days, even if you needed a 4-5x price split. And besides, it seems like this is the sort of thing that could sink power much easier than anyone else, while still returning a decent portion of it back to the grid later on, since big resistors are the easy way to sink power. That makes me think it would have a competitive advantage during unpredicted and very brief low-price events, even if other things are more efficient.

          Certainly, it’d make sense in helping against expectations of more spikes in the future, such as from solar power. But it’d do it by limiting the excesses of these spikes. Not to zero, but enough that it’s much more tolerable than the current situation. Really, what does it matter if the price variation doesn’t completely go away, so long as it’s reliable and affordable? If it can do it for a smaller cost than regular batteries, and without competing against portable devices and cars for the limited supply of regular batteries, it sounds like a fair idea.

          1. The point is that treating renewable power and the battery situation as two different things on the market is a fool’s errand, because there is ultimately no economic incentive to solve the problem. The solutions can exist only while the problem persists.

            Instead, we should mandate that the renewable generators/producers themselves buy the batteries by capping the amount of non-dispatchable random power they can sell on the market – a stability quota of sorts where you can’t just dump all the power you make to be someone else’s problem. This means removing the feed-in tariffs, price guarantees, and priority access laws that are presently forcing other producers to always yield in favor of wind/solar power.

            Of course that means renewable power becomes massively more expensive with the additional cost of the batteries (or other storage) paid directly by those who try to sell the energy, but this has already been the case all along. It’s just that other people are paying the difference while the renewable producers are raking in unearned profit.

            The situation is such that if we cannot make renewable power work without subsidies and arbitrary money shuffling, it will never scale up in the long term because governments can’t keep buying you power with your own tax dollars. We can’t keep pretending this is a “market” instead of a command economy.

          2. I would say we can *eventually* do that, by financial incentive if nothing else. But if we are going to make everyone pay their fair share for all the side effects of operating, fossil fuels have the biggest one of all. We’d have to add to the price of fossil fuel power however much it costs to turn the co2 and such back into fuel again. Or at least for taking an equivalent amount out of the atmosphere, since the first one is nonsense and the second is at least possible. Seems like it’s harder to pay for that than it is to pay for the side effects of some of the advantageous agreements renewables get.

          3. >for all the side effects

            That’s a red herring. We’re operating a system at cost X, and in order to replace it with another system, we’d have to pay Y, where Y is considerably more than X and we can’t afford that without running into energy poverty and other social ills.

            The problem is that we’re trying to replace an energy source that costs 1-2 cents a kWh for basic heat and process energy, with a different system that may end up costing 10-20 cents a kWh all told, and even though the first system might have externalities that cost 50 cents on top, we’re not ACTUALLY paying that, because we didn’t have to, which is why we’re in this situation.

            It’s all meaningless to say that we ought to pay the price for fossil fuels as well (and therefore it’s OK to pay more for renewable power), because we can’t. We have to come up with something that is AS CHEAP AS fossil fuels.

            Hint: there are such things, but they’re not convenient for the people who WANT energy to be more expensive, so they could then start commandeering the society to manage the social issues and disparities caused by expensive energy.

        2. The bit you’re missing there Dude is that almost all energy consumers are paying very much more fixed or even entirely fixed cost per unit – maybe you get cheap rates based on time of day. But the suppliers are not paying that fixed cost, they are bartering in ways that will be forever fluctuating even with the battery built in excess of requirements as they try to get the most profit out of the 25p/kWh you pay while still providing the service.

          That leaves lots of room the battery behind it to make money, selling only when its profitable/sustainable and probably ends up cheaper and more profitable for the electric producers and suppliers as well – without the battery the producers are going to be pushed towards building a much larger excess of power generation, which then lowers profitability of each generator built as the value of the units they produce in general drops because it is a market with excess too often, and the suppliers won’t like that either as it pushes them to charge less on the fixed rates for their customers – nobody would accept being charged a huge markup on the usual cost of power – which makes it likely they go bust the second you get a period of low supply…

          1. > that almost all energy consumers are paying very much more fixed or even entirely fixed cost per unit

            Not true anymore. The price volatility has meant that fixed unit price contracts are becoming rare and uneconomical. Almost all have some “time of use” component added to them.

            The power companies are shifting the risk of cost volatility to the unit price because they know you’ll be consuming most of your power typically when everyone else is, at peak demand, which also makes for the peak cost. The fixed unit price is always much more expensive than the average market price.

            The power companies are using this leverage to force more people into accepting hourly market rate contracts, so the consumers would turn into a “negative power reserve”. Since the producers can’t meet the demand, the market turns into demand management through massive price hikes to stop people consuming power when there isn’t any.

            It’s either that, or rolling blackouts, so this winter people have been turning their thermostats down and not having hot showers during the worst cold spell of the year. I count this as a fundamental failure of the energy grid – not being able to supply energy to the people when they’d need it the most.

          2. And, which is more profitable: hiking consumer prices up, or investing in batteries to reduce the price swings on the market?

            >the producers are going to be pushed towards building a much larger excess of power generation

            It’s actually the opposite. The producers are being pushed to build less new power and defer investments, since any conventional power plant has to yield for renewable power on the grid. It is not economical to operate like that, so it is simply not getting built. They’re also being forced to shutter down old coal plants, so more capacity is exiting the market than gets built.

            It’s literally the opposite of what “should” be happening. The difference is taken up by price hikes on the consumers rather than adding new capacity.

          3. As there is competition for the pot etc everyone is investing to claim their share (or hopefully even the whole pot pushing the others out of the market the way the OPEC nations like playing with oil prices and using their huge mass) – doesn’t mean the investments they are making really are optimal for efficiency or greening the grid.

            You will get no argument from me that the way subsidies and power pricing is handled in many places does not make a great deal of sense – but then essential public services being run as for profit companies that still somehow have to share so many resources has never made a great deal of sense to me. Competition can keep prices low and/or quality up only when you can actually really have competition organically, and in the case of supplying electric, water, sewerage, railways etc that really isn’t the case.

          4. >As there is competition for the pot

            You wish. Electric grids are natural monopolies, and trying to introduce “competition” on the market has lead to some nasty side effects, including collusion and price gouging.

          5. Dude: I bet there is a power pool where you live. I bet I had a hand in setting it up…

            Local electric distribution is the only natural monopoly in play here.

            Not interarea transmission, not generation. This is old news, don’t know how you missed it.

          6. > I bet there is a power pool where you live

            Of course there is. It consists of a small handful of large corporations who own all the generating capacity, and a multitude of small “power brokers” who do not own any generators or infrastructure and merely buy and sell power. All the “competition” happens between these tiny speculators, while the large corporations pretty much all do the same thing and don’t attempt to undercut each other.

          7. After all, since the grid stability depends on the collaboration and mutual agreements of the power producers, even if they’re nominally split into “competing” businesses, there cannot be real competition. If someone starts rocking the boat and playing silly games to “win” against the others, everyone suffers as the grid goes unstable.

    2. “On-shore wind is about $34 per MWh and utility scale solar LCOE is about $33 per kWh. So, not only not free, but more expensive than many other options.”

      Wait, compared to *what*? Sorry, what electricity cost are you saying is *under* an LCOE of $33/MWh??

      “Here in Texas, in winter, it’s not unusual for winter conditions to knock out solar for four or five days at a time,”

      What are you defining “knock out” to be? Because the lowest solar ever dropped to in one day in 2023, for instance, was ~20% of average production, and wind was even higher (40%). And of course Texas is unique in that it’s the smallest grid in the continental US, so those are ‘worst case’.

      “Nuclear is the only real option from an engineering standpoint.”

      There’s nothing wrong with fossil fuel plants to supplant renewables as needed. You don’t need to get to zero carbon, just reduce it a ton.

      I’m not arguing against nuclear, but the argument isn’t nuclear vs renewables, it’s nuclear vs fossil vs battery storage for dispatchable sources. There’s never going to be a real economic argument *against* renewables – you can always find a way to use excess energy. It’s just a question of how much dispatchable capacity you need, and where that should come from.

      And nuclear *does* have a drawback (besides the nonsense “taboo”) – it’s *very* capital intensive: you need a lot of money to start up and it takes a while to build, as opposed to other fuel types that generate early and can expand using their own profits.

      1. Nuclear is capital intensive because of politics. You have to fight 20 years to clear the red tape and deal with the NIMBYs, so you have to build it big enough to pay for those 20 years you lost money fighting the system.

        SMRs area cheaper, but again, no permits until someone has proven twice beyond doubt that every naysayer is wrong – without actually building any, because you can’t. It’s a catch-22.

        1. One of the ironies of nuclear power is that it’s very hard to get new reactor designs into production, because they’re not previously type approved, so they need to go through extensive certification and testing which spells massive delays and costs in construction, in each and every country that has their own nuclear safety agency that doesn’t collaborate with the others.

          It was possible for France alone to go from 0 to 70% nuclear power in just couple decades, because they simply built them. Of course the engineers had to submit all the details and tests, but once it was approved they just started making them. These days every new nuclear power plant is an individual, because they haven’t been making them like that since 1986.

        2. I trust the security measures of a big compound with plenty of workers and guards better than a lot of these “neighborhood reactor” ideas. In my old neighborhood, a tiny unguarded reactor would get raided or at least attacked/damaged eventually for certain. And even at greater size than that, if you’re not careful then organized crime groups might find it attractive to try their luck.

        3. “Nuclear is capital intensive because of politics.”

          No, it’s capital intensive because of *demand*. Yes, absolutely, regulatory problems amplify things, but even if everyone was happily approving reactor designs and permits were cheap it’d still be more capital intensive than a natural gas plant, because the bits and pieces involved in a nuclear infrastructure don’t have the volume needed to pull them down.

          Just imagine you started off with huge facilities in both gas and nuclear. Now imagine someone comes and says “hey, can you make me a tiny version of that” to both of them. Obviously the “small gas reactor” (=generator) is going to be cheaper, because it’s more useful – you can store it as needed and fuel it up quickly and when you don’t need it, it goes back into storage with little-to-no long term maintenance no problem. So the market’s bigger. Yes, I’m exaggerating a bit, but not a ton.

          I don’t disagree with you on “permits and regulations are killing nuclear” but you actually *really* need to subsidize it to balance it out against fossil fuels. The regulatory demands just kill an already difficult economic situation.

          1. “Capital intensive” is not an absolute term.

            A tiny gas generator is actually capital intensive compared to a huge CCGT plant, since the relative cost of the generator is still large compared to the unit cost of fuel, and since it’s a tiny generator it will probably never use much fuel.

            Think about a car for example. For the cost of a car, you can drive half a million miles. The cost of fuel is smaller than the cost of having the car.

          2. I guess I should qualify how it’s being used? By capital intensive, I mean that intrinsically requires more initial startup cash because it takes longer to start generating revenue. So it’s a combination of the initial cost plus lag to generate revenue. Also includes how much equity you gain by the initial cost.

            For nuclear, regulations are *absolutely* a huge part of that, but even if you get rid of that, you’d still be in trouble because 1) the parts are more expensive since the market’s smaller since the use case is more narrow, 2) the full supply chain is more restricted for the same reason and 3) the equity you gain by building it is lower for *again* the same reason, plus the obvious whole “high energy particles constantly spalling against your device make it harder to resell” thing.

            So no, a tiny gas generator wouldn’t be capital intensive because even if you used it for a short while, it retains the equity you paid for it.

            It’s the same thing with a car – if you buy a car for $30k, keep it for 5 years, drive 100k miles, and sell it for $20k, the capital cost wasn’t $30k, it was $10k (ignoring inflation), and the fuel cost to capital ratio is basically even.

          3. Dude: Most thermal plants cost less than 5% of their lifetime fuel cost. Granting CC plants are spendier than less efficient simple steam.

            In the USA, for 40 years, almost all new coal plants were built on the mine. Transport costs are killer, transmission is cheap.

          4. >Most thermal plants cost less than 5% of their lifetime fuel cost.

            Yep, due to economies of scale. In contrast, a 10-15 kW backup generator that you use once a year costs you thousands of dollars, and you’ll probably never run more than few hundred dollars worth of fuel through it, so it’s the reverse situation: 90% capital and upkeep, 10% fuel costs.

            Whether some technology is “capital intensive” depends entirely on how you utilize it. It is possible to make an SMR so simple and cheap that the fuel would be more expensive, but you’d probably have to scale it down to the size of those Russian RTGs that they keep finding abandoned on the tundra. That is to say, nuclear fuel is pretty damn cheap in terms of unit energy cost, because it carries so much energy per unit of fuel.

          5. >you’d still be in trouble because 1,2,3

            All of those are a result of the restrictive regulations.

            For the car which cost you $10k, if you drove it for 5 years, you probably didn’t drive more than 60-70k miles and at 40 miles a gallon you only spent 1,750 gallons of fuel. With an average price of $3 per gallon you spent about $5,000 on fuel, so that’s still 2:1 for capital vs. fuel. The car is still “capital intensive”.

          6. “For the car which cost you $10k, if you drove it for 5 years, you probably didn’t”

            I’m pretty damn sure I know how much I drive in a year and what fuel mileage and gas price I get. And I was actually being conservative, because I didn’t include maintenance and insurance costs.

            And if I *really* wanted to drive the point home, I could just go with the actual direct numbers, which is $3K purchase, $2.5K maintenance, 10 yrs, 200k miles, around $20k total fuel and $7.5K insurance. Which means the initial capital cost was 9% of the total. OK?

            And as to how that relates to the discussion at hand, there ain’t a large market out there for lightly used nuclear reactors.

      2. > it’s *very* capital intensive
        It’s not. Fundamentally, nuclear fuel is just a hot rock. Stick an engine on it and you’re done. You could have a guy in a lead suit shoveling U-238 into a boiler and it’d work. The only real cost is the refining process; the rest is just red tape to appease the illiterate masses.

        1. That’s not what capital intensive means. That’s the marginal running cost, and yes, it’s very low for nuclear. Capital intensive means it costs a lot to start up, because the facility and infrastructure costs a lot. Part of this is regulatory, but part is also just that the end to end process is more complicated. The longer it takes from beginning to money flowing in, the more money has to be borrowed and the higher overall cost.

    1. Anything compares favorably to giant flywheel storage.

      Simply because flywheel storage has so little energy density that the material and upkeep costs are proportionally ridiculous.

      1. This doesn’t. They are converting electricity to heat then heat to light then light to electricity. The highest efficiency solar cells are 44% efficient in normal day light. As this is incandescent light and will have fewer uv wavelengths and more red. Due to redder wavelengths having lower energy levels they will be less efficient for conversion with the photo electric effect.

        In short you would be lucky to get 10% out of what you put in.

          1. MIT is only hitting high efficiency because they are cherry picking shorter wavelength light to be used with their converter. This requires super high temps to be used and sustained. Something that isn’t going to happen with an energy storage device that uses incandescens.

      2. The flywheel almost always seems to come out price and efficiency wise as the absolute king for short term and high output power potential – it is the capacitor of energy storage game to some extent. So don’t write them off, very handy form of energy storage, cheap to build, no exotic materials, and able to dump energy at prodigious rates – won’t be the best choice for every job, but absolutely have a place.

        Might even be a good competitor for this concept – its not hard to scale up the flywheel array to store more energy if you have some space and you won’t end up consuming relatively rare materials to the same extent. So while the self discharge would be a bigger problem with the flywheel the cross over point where the better efficiency taking energy back out of the flywheel vs the rather low efficiency of this liquid tin concept might well be in that sweetspot that matches how long the system will tend to hold energy.

          1. I’d argue there is much more requirement to store shorter term than long – wind seems to be by far the most rapidly deployed by capacity and unlike solar it doesn’t keep to the hours of human activity or really care about the seasons very much at all. So with a grid of any reasonable size you can be fairly sure to get good renewable input from somewhere frequently enough that even a week of storage really is not needed. The requirement for hugely enduring energy reserves really comes in for smaller grids and grids that have no ability at all to manage demand – which really isn’t the case most of the time.

            Also it is not like a flywheel doesn’t do long term storage one you build it to sufficient scale, it just ceases to be as hugely efficient over time as that self discharge has been working long enough – though even for a week or two it might well be doing better efficiency than this relatively low efficiency liquid tin system that also will have self discharge significant enough to notice.

          2. Wind power starts to average out on a scale of 1-2 weeks. If by “short” you mean “hours within the day”, that is too short for wind power.

            Just last week we had no wind and extremely cold temperatures for the entire week, and the next 5 day forecast shows between 2-5 m/s wind speeds, which is not enough to put out ANY power from wind turbines. Rather, they’re consuming power because they need to heat up the hydraulics to keep them from breaking down. But, we had two days with 7-8 m/s wind speeds in the middle, which could have been used to catch a ton of energy IF we had enough storage capacity to last for a week.

            >even a week of storage really is not needed

            The best winds happen at autumn and spring. Summer and winter are both dead zones around here. If we really wanted to utilize wind power for a greater fraction of the year, a month of storage wouldn’t be enough.

          3. So expand your grid to interconnect with places that don’t share the exact same weather pattern you do – for instance the UK has some massive wind turbine farms in the North Sea, but there are heaps of them all over the country and an ever growing pile of interconnects to Europe too – so even if the North Sea is shockingly still the weather conditions that made that possible almost certainly mean the heaps of turbines everywhere else are working overtime…

            Or just put your wind in better places and pick a better turbine design for the location – 2m/s is doable and 5 well above the normal requirements of most modern turbine that seem to be aimed more for 3-4m/s as the slowest speed they work at.

            Also if don’t just put all your eggs in that one basket – have a bit of solar etc the odds get even better you have something working well during the highest demand periods – as the combination of no wind and no sun either across a generation grid of any real size isn’t going to be common. And if your grid has any users at all that have flexibility and will make cheaper products etc for having the cheapest energy when they are in high gear production and scale back the rest of the time… It is a small change in how some places will operate, and in many cases won’t be noticed at all but instantly can cut huge amounts of the daily energy consumption on your grid on the lean days.

          4. >So expand your grid to interconnect with places that don’t share the exact same weather pattern you do

            Wind power self-correlates with a radius of about 600 km. It’s a huge area – weather patterns are big. The entire Nord Pool exchange is having these problems, and that’s basically the entire Northern Europe with northern Germany and France.

            >2m/s is doable

            Remember how wind power is proportional to the cube of wind speed? Wind turbines reach their nominal power at around 16 m/s and at 6 m/s they produce only 5% of that. That’s their operating range. At 2 m/s you have 0.2% of the nominal power available in the wind, which means a big 130 meter 2 MW turbine could only produce 8 kilowatts even if the turbine would operate that low. It’s not even enough to run the electronics of the turbine itself. There is no turbine design that would be economical at 2-5 m/s wind speeds, because there isn’t enough energy or power available in low winds.

          5. >have a bit of solar etc

            In January? You’re not being serious – there’s less than 10 Watts per square meter of sunlight available at best, and the panels are covered in snow.

          6. Here’s London for example:


            Summer time availability is about 7 kWh/m^2 while in winter time it goes to 1 kWh/m^2 per day. Meanwhile, the demand for power does basically the opposite. This is a huge issue, because getting meaningful amounts of solar power in the winter would require you to build so massively in excess of demand that you’d simply have to toss most of the energy you generate half the year. Somehow you have to be able to shift a couple months worth of energy six months forwards in time to be able to build enough solar power to matter.

            This is why the DESERTEC plan was to recolonize North Africa and bits of the Middle East to have that “large enough” grid for stabilizing renewable power, using superconducting cables to shift the power around.

          7. >modern turbine that seem to be aimed more for 3-4m/s as the slowest speed they work at.

            That’s the cut-in speed where the turbine just barely produces more power than it consumes to operate the machinery. In the winter, blade heating requirements to stop ice from accumulating pushes the cut-in speed up higher – otherwise you end up throwing huge shards of ice around the neighborhood and hitting other turbines and infrastructure with it.

          8. Yes wind power scales with windspeed but you can’t actually state so categorically anything about how much they produce at wind speed x – as there are so darn many varieties and scales of turbine with old ones and newer ones and some designed and optimised for lower windspeed, some that flat out can’t run at all at that low (or high) windspeed at all, some that are very very reliable across a wide range of windspeeds but don’t have the same peak efficiency and may be more maintenance heavy etc..

            And yes weather patterns can be reasonably big, but they are also not static and not even close to as big as the grids across the EU as an example. It moves on and the distance to the outer edges where a turbine is going to be working really is that far to send electricity – it is a really really easy thing to transport efficiently over long distances.

            Also solar panels do work very nicely even entirely vertically mounted, so snow need only be a problem if you don’t put them in the right place, and they actually get rather more efficient in the cold – so you should get some reasonable power even on a short winters day, and importantly that power happens to be being created at the right time for people to be most active – which when talking about storage is great news.

          9. Dude while energy demands can go up in the winter, they can also go up in the summer… And there is this wonderfully simple technology like insulation that makes a very large difference in how much of a swing (if any) there will be between the two.

            But that potential swing is also so varied by climate, in some places that demand will never spike in the winter but go nuts in the summer as the Air Con is turned on, and many will have similar demands winter-summer as they get both extremes as the seasons change…

            In our house the heating is almost never turned on, as we almost never need it. It just doesn’t get and stay cold enough enough here to really need extra heat put into the house beyond the waste heat of living. Most of the time anyway. And this is a pretty darn old house with rather poor insulation compared to what is possible.

          10. >while energy demands can go up in the winter, they can also go up in the summer

            Yes, if you’re in California or Texas. In the case we’re talking about in the Nord Pool market region, the demand in June is roughly half of that in January because of the heating and lighting demands. Even electric cars start consuming double the energy because air density increases and they can’t use those skinny low-resistance tires for safety reasons in the winter.

          11. >but you can’t actually state so categorically anything about how much they produce at wind speed x

            Yes I can. I can state how much they COULD produce given wind speed X, and what they DO produce is always LESS than that. You can’t magically make a wind turbine produce more energy than is physically available at 2-5 m/s wind speeds.

            Likewise, you can pretty much calculate by physics how much sunlight in a day gets down to the ground in January in, let’s say Southern Sweden, and conclude that a solar panel no matter how you place it, even if you pay someone to brush it clean of snow and frost every day, won’t produce more than 5% of its nominal output and will cost you two euros a kWh in that condition because of the labor cost to keep it operating. What can you do?

        1. (more of a reply to you next post)

          > wind seems to be by far the most rapidly deployed

          A few years(?) back I saw this idea of big towers lifting weights up for energy storage.

          I wish there were a simple design basically combing wind turbines with an integrated weight lift system.
          You’ve already got the tower, a motor and a turning energy source.
          – When the grid is “full” use the wind to lift the weight.
          – When there’s no wind but the net needs more power let the weight pull the generator.
          – When there’s to much energy from PV lift the weight with the generator.

          1. The actual energy stored by the weight of things at heights is tiny with a couple exceptions. I think if your turbine lifted something its own weight to its own height, you’d have something like 50 kWh of potential energy. That’s of course tiny, vs the turbine’s output. It’s going to be smaller than e.g. flywheel storage, which is itself tiny compared to other storage methods.

            Exceptions: hydropower, with the massive quantities of water in the reservoir, and possibly trains in mountainous areas. If you’re carrying enough mass downhill with a train, then storing the energy in batteries can be enough to bring you back up the hill to get the next load. Might also apply to any electric trucks you could build, but of course only if you’ve got something you can deliver from top to bottom; usually products go the other way so you’re basically talking about a mine, probably.

  7. a lot of this article seems to come gushingly directly from a media release – they haven’t even built a reasonable pilot yet. Time will tell if it – and the ‘projected’ costs – are real.

  8. How do you insulate that many tons of 2400°C material such that it doesn’t loose tons of energy to the environment? Specifically, you’d have to insulate the load bearing structures to hold up what is no doubt a very heavy battery installation.

    1. None are 90% by the same metric. Turbines are often measured differently, and you’re probably thinking of the isentropic efficiency, which is the efficiency as a fraction of an imaginary ideal turbine. The true work output from a simple steam turbine plant as a fraction of fuel energy input is more in line with these, and can be worse than these. You get better peak efficiency if you can use higher temperatures, as in “CCGT” plants which aren’t just steam. You may or may not always achieve that though, where these would presumably insert and withdraw to maintain efficiency under changing load.

      1. Indeed, that was the point really – they need to be more specific with their comparisons and consider the whole system. I like this system from a perspective of simplicity, but when you can compare it to a chemical storage system, it really starts to look poor.

        1. Well no, or if that was the point then it’s not what I’m reading, because the percentages you’re giving and what you’re saying makes it seem like you believe the steam turbine makes a lot more electricity per quantity of heat. The steam turbine doesn’t turn 60-90% of the heat into electricity, it’s more similar to these 40-something-percent TPV devices. An ideal physically perfect turbine plant couldn’t do 90% either, not with the moderate operating temperatures involved. The CCGT plants can be more efficient than these things, but only by having a hot gas turbine first and a steam turbine second.

  9. Doesnt heat seem to be the worst possible form to store energy? Thermodynamic is comstantly trying to dissipate your heat. Lithium batteries are of course more expensive but once charged do not require further power to keep them charged for days/weeks. You would have to factor in the tin heat loss into the storage costs. Even better would be stored mass like pumped hydro which will retain the power essentially forever at the cost of keeping a valve closed. Water is pretty cheap compared to tin or lithium. Doesnt even need to be fresh water. Overall I find it hard to imagine a worse storage method than heat. Capturing light from glowing materials seems horribly inefficient since the heat to light conversion sucks horribly. This confirms my suspicions lately that a lot of green energy project are all about research funding and not about viable products.

    1. Research shouldn’t be about viable products, that’s business’s job. It should be about pushing boundaries, testing theory and enabling business to create viable products or avoid pitfalls/blind avenues. Where business and research cross, both compromise.

    2. Heat is also the way we acquire most of the energy we use – either by burning fuel in an engine or by using a gas or steam turbine. It’s also very easy to create, especially at a fast rate. Sure, it’s inefficient, but the point isn’t really to store power for a long time. If you’re doing that, you’re not making very much money because you only make money when you are moving power. At the same time, if it’s lithium batteries, they’re expensive and they wear out in a limited number of cycles, so even if you’re more efficient electrically, you may not decide it’s worth selling power until a bit higher price than you think. Your sell price has to be above your buy price not only by enough to cover your storage losses, but also to cover depreciation and the cost of interest on all the loans you took out to pay for the equivalent capacity.
      I dunno, it’s not guaranteed to be correct but it’s not a stupid idea.

  10. Think about it this way. You are trying to store enough heat to light an incandescent bulb and then collecting the light from it with a solar panel. There is no possible way that will ge efficient enough. You lose heat all through storage and transfer. You waste all the light energy that is not in the spectrum of the photovoltaics, you lose all of the light that does not strike the photovoltaics, then you have the efficiency loss of the photovoltaics themselves. Any system with that many conversions is gonna suck.

    1. Storing enough heat to light a lamp is misdirection. The heat IS the lamp, it’s its natural state it emits IR of course. The only conversion here is the TPV and the DC>AC components. But you’re right, storing heat is hard and converting heat back to elec is inefficient. But in real world products, we are not looking to make the most efficient solution possible, we are looking to make a system that is easy to manufacture, low maintenance and low cost and easy to deploy without masses of chemical processing and recycling problems or short lifespans. Heaters, tin and graphite tubes are cheap and easy. Perfectly efficient product, no, but that doesn’t make it inviable.

        1. What others have explained how not only do we already have data demonstrating a sufficient market for grid storage, but we expect the grid storage market to expand as the fraction of power which can be made available at any time decreases.

          If there was insufficient demonstrated variation in prices over a short period of time, or if we had no justification for why they think they can convert such a large percentage of the heat into electricity, maybe these comments insisting it can’t be viable would make more sense. But instead, how about a business question; will there always be volatile enough prices, or could the situation improve due to other factors, rendering the system less profitable than it currently would be? Will the idea actually work when someone tries to build it, or will something about it be problematic, perhaps the pump and high temperatures? Will the tin supply requirement be a problem? There are tons of reasonable doubts about being possible to actually execute; there’s no need to make up stuff and malign the core concept instead.

          1. Grid storage as a separate business has an economic case when the price variation is already bad enough to inconvenience people and cause problems. It’s a bubblegum patch on a broken tire.

            A small amount of storage can exist on the peak power market, since that will always exist, but the replacement of reliable base load power with intermittent renewable power creates a situation where the market is balancing between the additional cost of power reserves (the batteries) and the ability of consumers to adapt their demand by deferring use. In other words, it’s a bad compromise that costs more and works worse for everyone.

            In a situation where the quality of the product (i.e. availability and dispatchability of power) is becoming worse, nobody wants to pay more for it as well, so the utilities have no incentive to build power reserves – batteries or otherwise. It’s the consumers who have to yield, because they have no real leverage in this scenario.

            Think about it. What can you do? – if you refuse to buy power because it’s too expensive, then the power company doesn’t need the batteries to provide you with any. Why then should they buy the batteries? Out of charity?

  11. LOLOL …. After reading this error filled article, “wind/solar power is the cheapest for of energy production”, then reading the following remarks, I can only laugh. Is this writer that out of tune with reality or is this propaganda for the green energy aficionado?

  12. I’m no ecologist or physicist. Please, Shoot me down in flames with this question;
    Does this mean we get the opportunity to further warm the globe, without needing CO2 to do that job?

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