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.
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 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.
Interestingly this looks like the same principle as a rocket mass heater or masonry heater, but on a larger scale and powered by renewable energy. They say the system can retain heat for weeks whereas the smaller thermal battery in a masonry heater is exhausted in a matter of hours. I wonder if this is a function of size or if the tank is heavily insulated? It would be interesting if this same system could work at smaller scales for off-grid heating by harnessing excess solar capacity. There’s a lot of waste involved in going from solar to battery vs directly to thermal energy, as long as it doesn’t bleed off before you need to use it.
Wonder if one could use staggered heatpumps here - in summer there's quite a bit of heat out there (some of which needs to be removed) so you could get 3-6x more bang for your buck.
> 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.
Finland is still 25% oil for electric generation [1] (and almost 40% fossil fuel). That means a lot of the electricity to heat the sand still comes from oil. It makes me wonder if this is more efficient than just using oil heating. Or some hybrid approach that uses oil to heat the sand.
Of course there are other benefits: it's still a good way to level electric generation, which is important for e.g. nuclear plants and wind power.
It seems to depend on having a network to distribute heat, which is something that you have to take into account... basically when you create your town ?
Or is there a way to "retrofit" district heating into houses with their own gas boiler or heat pump ?
Good idea but why is it being measured in MW/MWh when it’s not an electrical battery? I know they can be converted but maybe it should be measured in actual thermal units like Btu?
Problem here is that if heating was done with electricity itself, it could have like 300% effective efficiency because of using heat pump, but a heat pump can't be used for 500C temperatures, it must be resistive heating. So even if no thermal loss occurs at all, we end up getting a lot, lot less heat than we could do otherwise. It's a lot better to use normal li-ion instead, surely 100 MWh means 500-ton battery and with longer life chemistries and thermal management, probably a 1000-ton one...
This is not a battery, this is thermal storage. No electricity is stored or generated. (Unlike liquid-metal batteries, for example, which are actual battery storage.)
It's not clear to me why you would hold 100 hours of energy, assuming you discharge at maximum power. If you want to store energy from summer to winter, then 4 days of energy is nothing. Even if your average discharge is only 30% of the maximum power, you still get only 2 weeks of energy. And if the use case is day to night, then 8 hours of storage is enough. Maybe the idea is that the houses in Finland are so well insulated that you need heating only in cases of extreme cold, and only during the night, 100 hours will do the job?
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[ 244 ms ] story [ 728 ms ] threadYou'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.
Really interested in seeing how it fares in reality, almost sounds too good to be true.
So this system could supply 12 houses? Shows the importance of proper insulation, which is still on our todo list.
> 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.
Of course there are other benefits: it's still a good way to level electric generation, which is important for e.g. nuclear plants and wind power.
[1]: https://ourworldindata.org/grapher/energy-consumption-by-sou...
Or is there a way to "retrofit" district heating into houses with their own gas boiler or heat pump ?