Finland creates "sand battery" in soapstone for storing thermal energy from renewable sources

[thewayne]

This is really cool.

In the town of Pornainen, they've built a 13 meter tall battery of "low-grade" sand that they warm-up to 450 degrees C - that 842 degrees F! - and it can hold that temperatures for weeks if not months, then they can use the hot air from it to heat the town's local heating network!

I think that's a pretty awesome use. They're using excess energy generated by renewable sources - free energy - to heat up the sand, then piping it around town. The former method to warm up the town was a woodchip furnace plant, clearly they're drastically cutting their CO2 footprint with this. And by using low-grade sand, their costs are pretty low.

But let's talk about sand for a minute. Businesses are literally dredging up ocean floors for sand to make more concrete. And you can't recover it from broken-up concrete when buildings are demolished. Now, to use sand to make a thermal battery I think is a worthwhile endeavor. I just wish they'd work out better ways to repurpose and recycle existing demolished concrete.

https://www.the-independent.com/tech/sand-battery-renewable-energy-finland-b2818348.html

https://hardware.slashdot.org/story/25/09/06/027211/a-very-finnish-thing-huge-sand-battery-starts-storing-wind-energy-in-soapstone

Comments

[silveradept]

Impressive, and hopefully it's good enough that they can use it for years upon end, recharging it as needed from the renewables. (And I wonder if it can scale into use in bigger populations.)

[thewayne]

It seems to me that it would be very low maintenance and should scale quite well.  The main thing would be that its most useable in towns that have central heating provided by town infrastructure.  I was reading recently about cities like Paris and others that rely on adjacent rivers for central cooling, and having problems with global warming raising river temperatures, they have kind of an inverse issue.

[silveradept]

In theory, you could possibly divert the excess heat (somehow) into some of these sand batteries and provide a cooler river, but the practicals of how are well being my expertise. I'm guessing it works mostly the same way as a heat pump system for a house, just much bigger capacities.