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Large-scale ‘sand battery’ goes online in Finland

energy-storage.news

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Re: Large-scale ‘sand battery’ goes online in Finland

#111

Post by stephen_g »

Swizec wrote: post #38
teruakohatu wrote: post #30

Earlier quoted context omitted.

Given how much health problems are caused by coal power plants, not sure it is that great to live near one. But if you have to have coal, it makes good sense to harvest the energy rather than wastefully pumping the steam into cooling towers.

I mean it’s already there and has been for 60 years. I’m sure its polution pales in comparison to the 200,000+ cars driving in the area daily. Back when the coal power plant was built it was pretty normal to live near coal burning things.

Unless it has a lot of flue scrubbing, it's likely to be far, far worse than 200,000 reasonably modern cars in terms of things like fine particulate matter emissions, NOx and SOx emissions, etc. which are the real bad ones for health issues.

Re: Large-scale ‘sand battery’ goes online in Finland

#112

Post by mikewarot »

pfdietz wrote: post #81
mikewarot wrote: post #9

Earlier quoted context omitted.

Moving sand (an abrasive grit) around is challenging at room temperate, doing it at 1000°F (500-600°C) seems impossible. It makes far more sense not to subject things to that kind of abrasion, and just flow air or water/steam through it.

It's possible. NREL's ENDURING system does just that. https://arpa-e.energy.gov/sites/default/files/2021-03/07%20D... Quick stats: stores heat in sand at 1200 C, round trip power->power efficiency of 54%, LCOS of $0.05/kWh for 100 hour storage. Heat is transferred from the sand to the gas for a Brayton cycle by direct contact in a fluidized bed heat exchanger. Babcock and Wilcox is expanding this now to the pilot sta…

That is a very elegant work around. {They never convey the particles while hot, only after they've given up their heat, or before they get heated and then fall into hot storage}

I'd be happy with 54% round trip efficiency, it's way better than losing renewable power by not being able to store it.

Re: Large-scale ‘sand battery’ goes online in Finland

#113

Post by WalterBright »

tjmc wrote: post #101
WalterBright wrote: post #93

I've proposed several times on HN a "box of rocks" at the house level to store heat/cold when electricity is cheap, and release heat/cold when electricity is expensive. It was ridiculed every time. I should have patented it :-)

HVAC engineer here. At the residential level this is already achievable with hot water storage from either solar thermal and/or heat pumps. Plus you get to use the hot water (assuming you've sized the tank correctly!) Storing heat in rocks or sand doesn't make sense from a thermal efficiency standpoint unless the temperature is high and that isn't economically viable unless you have large volume storage - typically d…

How can it not be efficient? The heat to heat a rock is 100% recovered when the rock cools back down.

A tank of water works, too, but tanks rust, mildew, and leak.

Re: Large-scale ‘sand battery’ goes online in Finland

#114

Post by duxup »

gamegoblin wrote: post #14
pavon wrote: post #8

As an American it completely breaks my expectations that district heating not only works can be more efficient that decentralized heating. The amount of heat lost just moving water from the water heater on one side of the house to the shower on the other is ridiculously high in houses here. The idea that you can insulate well enough to efficiently move heat across a city is amazing to me.

Many American universities use district heating for the whole campus. Also, as made famous by the many steam vents in NYC movie shots: https://en.wikipedia.org/wiki/New_York_City_steam_system . More info: https://en.wikipedia.org/wiki/District_heating#United_States

University of Minnesota still has it and has been upgrading it:

https://cpm.umn.edu/combined-heat-power-plant

Re: Large-scale ‘sand battery’ goes online in Finland

#117

Post by hunter-gatherer »

WalterBright wrote: post #93

I've proposed several times on HN a "box of rocks" at the house level to store heat/cold when electricity is cheap, and release heat/cold when electricity is expensive. It was ridiculed every time. I should have patented it :-)

Interesting idea. Something I do on cold nights when camping in the back country is to put some rocks in my fire and bury the firepit when the coals are hot and sleep on top of that. Usually keeps me warm enough to at least get 4 or 5 hours of comfortable sleep during cold nights.

Re: Large-scale ‘sand battery’ goes online in Finland

#118

Post by WalterBright »

hunter-gatherer wrote: post #117
WalterBright wrote: post #93

I've proposed several times on HN a "box of rocks" at the house level to store heat/cold when electricity is cheap, and release heat/cold when electricity is expensive. It was ridiculed every time. I should have patented it :-)

Interesting idea. Something I do on cold nights when camping in the back country is to put some rocks in my fire and bury the firepit when the coals are hot and sleep on top of that. Usually keeps me warm enough to at least get 4 or 5 hours of comfortable sleep during cold nights.

Yup. When I watch "Alone" where the contestants are supposedly survival experts, I often wonder about their ineptness around fire, fireplaces, chimneys, etc. None seem to have hit on the idea of putting a rock in the fire, then wrapping it in some insulation then putting it in the sleeping bag.

Some make themselves sick from the smoke (inadequate chimney), more than one burned down their shelter.

(I have no idea how to hunt & fish, but I bet I could build an adequate shelter and fireplace.)

Re: Large-scale ‘sand battery’ goes online in Finland

#119

Post by riku_iki »

tjmc wrote: post #101
WalterBright wrote: post #93

I've proposed several times on HN a "box of rocks" at the house level to store heat/cold when electricity is cheap, and release heat/cold when electricity is expensive. It was ridiculed every time. I should have patented it :-)

HVAC engineer here. At the residential level this is already achievable with hot water storage from either solar thermal and/or heat pumps. Plus you get to use the hot water (assuming you've sized the tank correctly!) Storing heat in rocks or sand doesn't make sense from a thermal efficiency standpoint unless the temperature is high and that isn't economically viable unless you have large volume storage - typically d…

Article says they heat sand up to 500C, which is not very possible with water.
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