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

[disneydream06]

They are digging up the ocean to make concrete? :o :o :o

But the battery idea sounds good. :)
Hugs, Jon

[armiphlage]

You CAN crush concrete back into sand, and you can crush freshly-quarried rocks into sand. It's even better for construction than sand dredged up from the ocean (the sharp edges on the particles pack better than rounded particles, which roll around). But it's a tiny bit cheaper to just steal someone's beach.

The Nova Scotia Power Corporation encourages residents to get an Electric Thermal Storage system. It's an insulated box about the size of an end table. During the night, when electricity is cheap, an electric heater turns bricks red-hot. When you need heat, a small fan blows air past the bricks, heating it up to warm your room.

https://www.elnur.es/wp-content/uploads/2018/03/ECOMBI-PLUS-Smart-storage-heater-Technical-Sheet.pdf

https://www.nspower.ca/your-home/energy-products/heating-cooling#:~:text=Electric%20Thermal%20Storage&text=When%20paired%20with%20our%20Time,throughout%20the%20day%20as%20needed.

[disneydream06]

That sounds very cool. :)

[bibliofile]

oooOOOOoooohh

Back in the '70s, a local ecology center built solar panels* and filled a storeroom with rocks to retain the heat. I never asked how well it worked, but it's the same idea innit.

* With wood and corrugated roofing. Got brown & black enamel paint all over my new painter's paints; made my mom mad.

[armiphlage]

Oooh, I remember those, like Trombe wall thermal storage! If I remember, the problem with them was that designers tried to rely on natural convection to distribute the heat. That doesn't work very well as the rocks come closer to room temperature, so you don't get all the stored energy out to where people need it. If you add a little fan, they work much better.

[death_and_decay]

Exactly!!! Mahtava! I wish that the Orangetang (sp?) would comw to his senses and learn from the Finns!!!

[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.