> A comment on the YouTube video below complained, “Not a word about return on investment in the presentation. That means it’ll never pay off” MAGAlomaniacs are everywhere these days.
Given the supposed 50+ year lifespan of such a battery, I find it hard to believe it doesn't turn a profit at some point. And I understand that debunking low-effort accusations is asymmetric warfare. But why cite a random YouTube comment if you have no intention of addressing its claims? A more charitable interpretation is that it's meant to ragebait the readers. But to me, it seems like trying to make people feel ashamed for having doubts, by making a public example of a skeptic.
If, say, further insulating your house or building a sand battery will pay for itself in 50 years, it's a bad investment, financially speaking, and probably environmentally speaking as well. You can deploy "the same amount" of resources in something else with a higher ROI, like maybe solar panels with a one-year payback, and get a much bigger benefit. This is an important consideration as long as you are constrained by some kind of resource limitation.
I agree with you, but one point I see everyone missing is the fact that this is a first-time installation of a new technology that hasn’t scaled. There needs to be a business plan of course. At the same time, no one would expect to see ROI figures for the first build of a concept car.
Finland is the only country in the world where solar isn't the cheapest form of electricity because they get so little sun and they have good alternatives.
There's also some long-term risk here. If we, humans, did massive amounts of dispatchable solar and wind, plus systems like this, static battery storage, other storage and things like widespread EV capacity arbitrage, it's not guaranteed that the negative or even low energy price events would even happen. The more people think they can store it and sell it later, the higher the demand for off-peak power. You could end up with op-ex exceeding revenue in the future.
Then again, the same also goes for the other storage methods as the spread compresses. Eventually, as always, it all comes down to who can do it on the thinnest shoestring. 1/4 the cost, but the thermodynamic efficiency is 1/3 (direct heat vs batteries + heat pump, say) is still a winner. Finns aren't going to stop needing heat in winter soon, and if you can provide it even a fraction under the cost of battery electricity and a heat pump, you get the customer. And the district heat infrastructure probably already exists.
Its of course true that this will somewhat even out once storage becomes more available. But there are still market forces at play. If the electricity prices are higher, operators have a renewed financial incentive to generate more power (more power = more revenue), for example by re-powering solar and wind farms.
Theoretically this would be an endless cycle, which is of course constrained by very practical needs of the electricity users.
People nowadays expect 10% return on their investment, so if you invest 1m you need to make 100k a year from it (120k to cover the deprecation over 50 years)
If you made 30k a year for 50 years you'd return 1.5m from your 1m investment, but you're only making 3%, which is a low return especially given the future risk (you'd have to run for 33 years just to get your initial investment back)
Either way it's worthwhile, because the reason people expect 10% is because the externalities are borne by others. Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment, and judging investments only on the immediate financial reward already biases the conversation
> Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment
It's partially that, other part is that we aren't really pricing in all the externalities of everything out there. So it's not that "there's no ROI", it's that "we aren't factoring things in the ROI calculation".
So while a heat battery might not make a huge profit, the ability to burn less fuel (less air pollution, less waste, etc), to offer redundancy and stability, the know-how and work it creates, that is all valuable as well.
> Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment
I think this is a little unfair. If it were true, it would be the reason for wealth inequality: you're saying that the majority of people and countries are so financially irresponsible that they consume any resources they get without investing any. But in fact everyone I have observed closely, in every socioeconomic group, tries to optimize ROI. Most of them aren't very good at it, but they do try.
On the other hand, people who expect a 10% risk-free return are just going to get scammed. There are 10% opportunities in most people's lives—weatherstripping, coupon clipping, bulk food buying, etc.—but you can run out pretty quickly.
> And I understand that debunking low-effort accusations is asymmetric warfare
Is the comment even that unfair? Asserting that it will never pay off because the presentation avoided mentioning anything about the payoff might be a little bit cynical, but not terribly so. It could be fairly presumed that if the project is a clear economic win, they would be proudly bragging about it; and the opposite presumption is also reasonably fair, even if it turns out to be wrong.
And what does such cynicism have to do with "MAGA"? That asserted association seems much worse than the initial cynical assertion.
> Given the supposed 50+ year lifespan of such a battery
Surely the lifespan is almost forever. It's just a tank full of sand and some heating pipes. Maybe the pipes and/or control electronics needs to be replaced occasionally, but nothing should happen to the sand inside - like ever.
The battery (am assuming it's just sand and metal) should be very cheap compared to Lithium especially in the places where you generated solar energy (they are hot and have a lot of sand).
The problem is: is it profitable to even store energy there? There is no mention beyond "In operation, the sand battery has demonstrated a round trip efficiency of 90 percent.". That doesn't mean much if you do not compare it to Lithium and you don't give me a breakdown of the costs.
The other thing: Size. Is that big thing enough to store energy for a city? a neighborhood? A building? A house?
If it's enough just for a house, then I have trouble seeing this scale.
Unfortunately, people seem to see Boogeymen everywhere when they're terminally online. It's kind of like the mid-2010s where everything someone didn't like was "fascist" or "Nazi"
I find it fascinating that renewables always have to have a ROI.
nobody cares about his car loosing value as soon as you drive off the parking lot. Or any other appliance - a fridge will never have a ROI, a washing machine will not and neither will a stove, a macbook or a fancy smart home system. They are part of our live, loose value and we accept that.
But solar or batteries (granted, mostly with home-solutions)? Better make money, otherwise why even bother.
Does anyone understand why people do this? I mean, really why? It's similar to eg climate protestors quoting all kinds of outrageously incorrect statistics as fact, or saying that $TECH can supply "4% of all households" with electricity, fully knowing that households only consume a tiny % of total energy, and so on.
I simply don't get it! The political landscape across the west is that there's swaths of people who've simply stopped believing mainstream media when they're reporting things, and somehow our reaction is to just lie even more? Try to out-lie camp Trump? I mean I don't think it's even possible to lie more than Trump so wouldn't the honest, nuanced truth be a a much better antidote than global left's current strategy of "also lie, but a bit less"?
I simply don't understand where it comes from. Like in what bizarro world is this shit a smart strategy? Is it all just incompetence?
It has nothing to do with political partisanship (except to the extent that false-flagging happens or that powerful individuals have bad ideas about how to propagandize for their cause). Most people are just terrible at critical thinking, and most of the interesting claims (especially statistical ones) are simply not verifiable by random individuals.
Plenty of leftists have their own reasons to distrust media. But scarcely anyone imagines reasons why someone else would lose trust. Not that they could do anything about it anyway.
The "global left" is not a real thing. I mean, of course you can draw lines around groups any way you like, but this one doesn't offer meaningful insight.
I like these technologies. They may not be as energy efficient as using more exotic materials, but what they do use is simple, cheap and often sourced locally. Such economic factors are often as important to the ROI as the purely scientific ones.
I think with enough renewable in the grid, there will always be times when the costs are 0 or negative, so you can help stabilize the grid by consuming.
Are there downsides to "just" sending all of the extra energy to ground? I've often wondered why overpowering the grid has been talked about as this huge unsolvable problem.
I understand it's wasteful, of course, but waste in a ecosystem of vast abundance seems like a feature, not a bug.
You'd think water would be easier to exchange heat with since it can slosh around the heat exchanger elements in the tank more easily. Which should translate to lower costs since you don't need as many exchanger structures in the medium.
Any guesses for the motivation in using sand? Maybe it's that you can heat it over 100C? But then big heat differences to the environment mean high conductive/radiation losses or heavier insulation requirements.
Sand also mostly stays where you put it. While obviously water can be put in tanks easily enough, there's still more maintenance and inspection required and a gigantic watertight tank that will last n decades is substantially more expensive then a steel sand box. Plus it only goes to 100C unless you pressurise it and that really gets hard. Unplanned release of that much water at 100C is also extremely dangerous. Whereas even 500C sand will mostly just sit there. Plus the usual corrosion and scaling effects water systems love to develop at high temperatures.
Insulation isn't such an issue with sand because sand itself is fairly good insulator and obviously doesn't convect. 1m of sand is about the same as 10cm of air. 500C through 1m of sand if roughly 125W/m². Which isn't nothing but it's also 7m from the center to the edge, and the efficiencies only improve the bigger you make the silo.
Presumably they have a double-skin gap and other external insulation too. As the Icelandic hot water pipe systems show, which drop only a few degrees C over hundreds of kilometres of pipe (and thus a gigantic surface area to volume ratio), you can have really quite good insulation if you have space to make it thick.
The hassle of handling hot water is also presumably why they use hot air rather than water as a working fluid for heating the sand in the first place. The worst case if you spring a leak in a heat-transfer tube inside the tank is that a bit of air escapes. Leaking super-heated high-pressure water or steam into the (unpressurised) tank would be a much larger problem, and unloading up to 2000 tonnes of hot, damp, sand to plug it would be operationally very annoying if nothing else.
"Rock, sand and concrete has a heat capacity about one third of water's. On the other hand, concrete can be heated to much higher temperatures (1200 °C) by for example electrical heating and therefore has a much higher overall volumetric capacity."
and
"Polar Night Energy installed a thermal battery in Finland that stores heat in a mass of sand. It was expected to reduce carbon emissions from the local heating network by as much as 70%. It is about 42 ft (13 m) tall and 50 ft (15 m) wide. It can store 100 MWh, with a round trip efficiency of 90%. Temperatures reach 1,112 ºF (600 ºC). The heat transfer medium is air, which can reach temperatures of 752 ºF (400 ºC) – can produce steam for industrial processes, or it can supply district heating using a heat exchanger."
I learnt some new concepts here, specific heat capacity vs overall volumetric, things I kind of understood intuitively, but now much clearer:
If I add some fixed amount heat to some fixed volume of water, it might rise by 1℃, while the same volume of concrete rises by 3℃. And by the same logic, on release, that fixed volume of water dropping by 1℃ releases 3x as much heat as when that fixed volume of concrete drops by 1℃.
So if you can max heat water to 100℃, and max heat concrete to 1200℃, and on release you let it go to 10℃ (probably the range is less in practice), then the water can drop 90℃ and the concrete 1190℃, so even if the water releases 3x the amount of heat per ℃, the water just releases 270 (per volume) while the concrete releases 1190 (per volume)
> But then big heat differences to the environment mean high conductive/radiation losses or heavier insulation requirements.
Square cube scaling means that insulation becomes trivial in total costs as you scale the installation up. Something that's convenient for a single household would probably be too hard to insulate, but this thing holds 2000t of sand.
To be pedantic, yes you can but you'd need to pressurize it to uuhh... According to this calculator [0], you can get water to 370 degrees C if the pressure is 207 atmospheres, which is about the pressure of the ocean two kilometers deep.
District heating tends to operate at 50-70C at lowest. But more often up to 115C and in some case even 180C.
Even the lower range doesn't leave much delta in best case of boiling water. So you would need some type of heat pumps instead much simpler heat exchangers. So that is also one cost optimization.
And of course it's still a win if you can heat the return water half of the way to spec with the battery, it's not necessary to have the battery heat it all the way to the plant outgoing temp.
District heating systems have been happily using ~90C water based heat batteries for a long time.
For this specific use case, you need to heat to far above the boiling point of water to retain some thermal efficiency. Sand/rock is better suited for storing the thermal energy at ~500 celcius.
perhaps sand is easier to heat to higher temps, and also it's less thermally conductive, so you'd lose less heat in storage for the same sized container.
Several cities in Finland have water based thermal batteries already, connected to local district heating networks. They have been previously used to store energy from existing combined heat and power plants, but now that wind power build up has created a lot of excess cheap power period, have been modified to include electric boilers.
Helsinki has advanced integrated district heating and cooling. Over 300 MW of heat pumps by 2025.
Collecting heat from wast water is free energy. When you defecate, wash clothes or dishes, or take shower there is warm water and solids going down the pipes. That heat can be used. In the summer stored cold sea water can provide district cooling.
There are significant trade-offs with this technology.
It's storing heat, so if you need electricity then you eat a lot of efficiency. I think Vernon said ~45% round trip efficiency. Batteries are 90%+.
The storage is at a high temperature (500-600C) which means that you can't use heat-pumps to produce the heat to be stored. This means that you miss out on ~400% energy gains possible from converting electricity to heat.
So the efficiency is pretty low.
That said, solar PV is really cheap and moving large amounts of earth into a pile is also a very much solved problem so in some cases, notably higher latitudes which have very long days and low heat/electricity demand in the summer and the opposite in the winter, it could still be a very good solution.
The whole point is that the thermal energy is used directly, via district heating. These are not meant to store energy for electricity production (though they could do that if really needed – emergency power for various facilities? Maybe not worth it compared to diesel.)
Heat from existing thermal power plants can be stored directly and later distributed with no conversion loss; excess electricity from renewables can be turned to heat at 100% efficiency, but the problem is that peak heat demand and peak electricity supply do not typically coincide. Heat batteries are meant to solve that problem.
I live in a desert where we have district cooling (and no shortage of sand or solar power), instead of district heating. Wonder if they can pull off the same trick.
Well you can't really do -600C sand (or anything), so the benefits of sand VS water largely diminished. "just" freezing water already gives you around 300C equivalent of sand (if my napkin is correct).
Also the point of this plant is to exploit the counter-correlation of cheap electricity and cold. Usually there is a bigger correlation between cheap electricity and heat.
You can use heat to create cool by using absorption materials. It's of course way more complicated than with heat. But anyway with that, stored heat in sand could be used to create district cooling.
In theory, yeah, cooling the sand would work, and it wouldn't freeze / expand. You'd need to use a coolant that doesn't freeze though, and of course keep any liquid out of it.
Readit News
> A comment on the YouTube video below complained, “Not a word about return on investment in the presentation. That means it’ll never pay off” MAGAlomaniacs are everywhere these days.
Given the supposed 50+ year lifespan of such a battery, I find it hard to believe it doesn't turn a profit at some point. And I understand that debunking low-effort accusations is asymmetric warfare. But why cite a random YouTube comment if you have no intention of addressing its claims? A more charitable interpretation is that it's meant to ragebait the readers. But to me, it seems like trying to make people feel ashamed for having doubts, by making a public example of a skeptic.
So I think ROI is a first-order consideration.
Then again, the same also goes for the other storage methods as the spread compresses. Eventually, as always, it all comes down to who can do it on the thinnest shoestring. 1/4 the cost, but the thermodynamic efficiency is 1/3 (direct heat vs batteries + heat pump, say) is still a winner. Finns aren't going to stop needing heat in winter soon, and if you can provide it even a fraction under the cost of battery electricity and a heat pump, you get the customer. And the district heat infrastructure probably already exists.
Theoretically this would be an endless cycle, which is of course constrained by very practical needs of the electricity users.
If you made 30k a year for 50 years you'd return 1.5m from your 1m investment, but you're only making 3%, which is a low return especially given the future risk (you'd have to run for 33 years just to get your initial investment back)
Either way it's worthwhile, because the reason people expect 10% is because the externalities are borne by others. Majority of people and countries in the world do not deem ROI to be the sole or even primary driver for investment, and judging investments only on the immediate financial reward already biases the conversation
It's partially that, other part is that we aren't really pricing in all the externalities of everything out there. So it's not that "there's no ROI", it's that "we aren't factoring things in the ROI calculation".
So while a heat battery might not make a huge profit, the ability to burn less fuel (less air pollution, less waste, etc), to offer redundancy and stability, the know-how and work it creates, that is all valuable as well.
I think this is a little unfair. If it were true, it would be the reason for wealth inequality: you're saying that the majority of people and countries are so financially irresponsible that they consume any resources they get without investing any. But in fact everyone I have observed closely, in every socioeconomic group, tries to optimize ROI. Most of them aren't very good at it, but they do try.
On the other hand, people who expect a 10% risk-free return are just going to get scammed. There are 10% opportunities in most people's lives—weatherstripping, coupon clipping, bulk food buying, etc.—but you can run out pretty quickly.
This is why I open the comments before the link.
Is the comment even that unfair? Asserting that it will never pay off because the presentation avoided mentioning anything about the payoff might be a little bit cynical, but not terribly so. It could be fairly presumed that if the project is a clear economic win, they would be proudly bragging about it; and the opposite presumption is also reasonably fair, even if it turns out to be wrong.
And what does such cynicism have to do with "MAGA"? That asserted association seems much worse than the initial cynical assertion.
"Everyone i don't like is Hitler". It's a rather immature way of disagreeing.
There is a KYM page about this phenomenon: https://knowyourmeme.com/memes/everyone-i-dont-like-is-hitle...
Dead Comment
Surely the lifespan is almost forever. It's just a tank full of sand and some heating pipes. Maybe the pipes and/or control electronics needs to be replaced occasionally, but nothing should happen to the sand inside - like ever.
The sand is the least complex part. Industrial facilities like this take a lot to keep running.
The problem is: is it profitable to even store energy there? There is no mention beyond "In operation, the sand battery has demonstrated a round trip efficiency of 90 percent.". That doesn't mean much if you do not compare it to Lithium and you don't give me a breakdown of the costs.
The other thing: Size. Is that big thing enough to store energy for a city? a neighborhood? A building? A house?
If it's enough just for a house, then I have trouble seeing this scale.
nobody cares about his car loosing value as soon as you drive off the parking lot. Or any other appliance - a fridge will never have a ROI, a washing machine will not and neither will a stove, a macbook or a fancy smart home system. They are part of our live, loose value and we accept that.
But solar or batteries (granted, mostly with home-solutions)? Better make money, otherwise why even bother.
- Fridge: has ROI vs. going to the store more often or getting food poisoning.
- Washing machine: Has ROI measured in the value of your time spent not slapping clothes against a board to make them clean.
- Stove: ROI vs. using and maintaining a fire pit, with the risk of burning your house down factored in.
- MacBook: ROI is how much work you can get done vs. a Windows machine, or not having a laptop and doing math really fast by hand on paper.
Etc. It is suspicious that there isn’t a “this will pay for itself in N years vs. not having it” statement somewhere.
Deleted Comment
I simply don't get it! The political landscape across the west is that there's swaths of people who've simply stopped believing mainstream media when they're reporting things, and somehow our reaction is to just lie even more? Try to out-lie camp Trump? I mean I don't think it's even possible to lie more than Trump so wouldn't the honest, nuanced truth be a a much better antidote than global left's current strategy of "also lie, but a bit less"?
I simply don't understand where it comes from. Like in what bizarro world is this shit a smart strategy? Is it all just incompetence?
Plenty of leftists have their own reasons to distrust media. But scarcely anyone imagines reasons why someone else would lose trust. Not that they could do anything about it anyway.
The "global left" is not a real thing. I mean, of course you can draw lines around groups any way you like, but this one doesn't offer meaningful insight.
Dead Comment
Dead Comment
yes and given that the energy you put in is practically free, it doesn't matter if it's not as efficient.
I understand it's wasteful, of course, but waste in a ecosystem of vast abundance seems like a feature, not a bug.
You'd think water would be easier to exchange heat with since it can slosh around the heat exchanger elements in the tank more easily. Which should translate to lower costs since you don't need as many exchanger structures in the medium.
Any guesses for the motivation in using sand? Maybe it's that you can heat it over 100C? But then big heat differences to the environment mean high conductive/radiation losses or heavier insulation requirements.
Insulation isn't such an issue with sand because sand itself is fairly good insulator and obviously doesn't convect. 1m of sand is about the same as 10cm of air. 500C through 1m of sand if roughly 125W/m². Which isn't nothing but it's also 7m from the center to the edge, and the efficiencies only improve the bigger you make the silo.
Presumably they have a double-skin gap and other external insulation too. As the Icelandic hot water pipe systems show, which drop only a few degrees C over hundreds of kilometres of pipe (and thus a gigantic surface area to volume ratio), you can have really quite good insulation if you have space to make it thick.
The hassle of handling hot water is also presumably why they use hot air rather than water as a working fluid for heating the sand in the first place. The worst case if you spring a leak in a heat-transfer tube inside the tank is that a bit of air escapes. Leaking super-heated high-pressure water or steam into the (unpressurised) tank would be a much larger problem, and unloading up to 2000 tonnes of hot, damp, sand to plug it would be operationally very annoying if nothing else.
"Rock, sand and concrete has a heat capacity about one third of water's. On the other hand, concrete can be heated to much higher temperatures (1200 °C) by for example electrical heating and therefore has a much higher overall volumetric capacity."
and
"Polar Night Energy installed a thermal battery in Finland that stores heat in a mass of sand. It was expected to reduce carbon emissions from the local heating network by as much as 70%. It is about 42 ft (13 m) tall and 50 ft (15 m) wide. It can store 100 MWh, with a round trip efficiency of 90%. Temperatures reach 1,112 ºF (600 ºC). The heat transfer medium is air, which can reach temperatures of 752 ºF (400 ºC) – can produce steam for industrial processes, or it can supply district heating using a heat exchanger."
If I add some fixed amount heat to some fixed volume of water, it might rise by 1℃, while the same volume of concrete rises by 3℃. And by the same logic, on release, that fixed volume of water dropping by 1℃ releases 3x as much heat as when that fixed volume of concrete drops by 1℃.
So if you can max heat water to 100℃, and max heat concrete to 1200℃, and on release you let it go to 10℃ (probably the range is less in practice), then the water can drop 90℃ and the concrete 1190℃, so even if the water releases 3x the amount of heat per ℃, the water just releases 270 (per volume) while the concrete releases 1190 (per volume)
Square cube scaling means that insulation becomes trivial in total costs as you scale the installation up. Something that's convenient for a single household would probably be too hard to insulate, but this thing holds 2000t of sand.
[0] https://www.engineeringtoolbox.com/water-vapor-saturation-pr...
Even the lower range doesn't leave much delta in best case of boiling water. So you would need some type of heat pumps instead much simpler heat exchangers. So that is also one cost optimization.
And of course it's still a win if you can heat the return water half of the way to spec with the battery, it's not necessary to have the battery heat it all the way to the plant outgoing temp.
District heating systems have been happily using ~90C water based heat batteries for a long time.
For those who haven't seen it there is a famous Mark Rober video: https://www.youtube.com/watch?v=My4RA5I0FKs
Collecting heat from wast water is free energy. When you defecate, wash clothes or dishes, or take shower there is warm water and solids going down the pipes. That heat can be used. In the summer stored cold sea water can provide district cooling.
Really interested in seeing how it fares in reality, almost sounds too good to be true.
There are significant trade-offs with this technology.
It's storing heat, so if you need electricity then you eat a lot of efficiency. I think Vernon said ~45% round trip efficiency. Batteries are 90%+.
The storage is at a high temperature (500-600C) which means that you can't use heat-pumps to produce the heat to be stored. This means that you miss out on ~400% energy gains possible from converting electricity to heat.
So the efficiency is pretty low.
That said, solar PV is really cheap and moving large amounts of earth into a pile is also a very much solved problem so in some cases, notably higher latitudes which have very long days and low heat/electricity demand in the summer and the opposite in the winter, it could still be a very good solution.
Heat from existing thermal power plants can be stored directly and later distributed with no conversion loss; excess electricity from renewables can be turned to heat at 100% efficiency, but the problem is that peak heat demand and peak electricity supply do not typically coincide. Heat batteries are meant to solve that problem.
Also the point of this plant is to exploit the counter-correlation of cheap electricity and cold. Usually there is a bigger correlation between cheap electricity and heat.
You can if you stagger AC/HP or even peltier elements.