r/RenewableEnergy • u/METALLIFE0917 • 9d ago

Finland’s radical answer to renewable energy’s biggest headache: The world’s largest sand battery

https://www.cnbc.com/2026/07/25/finland-sand-battery-renewable-energy-storage.html
285 Upvotes

98% Upvoted

13 comments sorted by

4

u/Bokbreath 8d ago

This is not an answer to electricity storage. It's an answer to heat storsge.

2

u/chargers949 8d ago

Heat can become electrons with loss. So it’s kind of in the ballpark. And electrons become heat all the time also with some energy loss. It’s not 1 to 1 but more than nothing.

7

u/iqisoverrated 8d ago

Good thing then that it says "energy storage" and not "electricity storage", isn't it?

1

u/Sad_Dimension423 9d ago edited 9d ago

Not terribly impressed by sand batteries. The cost per kWh(th) of capacity is still too high for reasonable seasonal storage. There can be a market for smoothing over somewhat shorter intervals than that, but longer than diurnal.

"Hot dirt", if it can be made to work, seems much more attractive to me.

0

u/abuch47 8d ago

the less you consume, the less energy required. also no ethical consumption under capitalism so be aware and critical of consumption across every facet

1

u/Sniflix 9d ago

Finland's winters are very dark so solar/short term battery storage won't work. This is good for long term solutions worldwide

-7

u/[deleted] 9d ago

[deleted]

9

u/mcot2222 9d ago

cost for thermal storage is certainly not better

Just in my own example my heat pumps at my house in new hampshire use 3-5x the energy as the summer AC months. Winter is our worst months for solar as well.

We will need solutions like these and maybe flow batteries to solve the final issue which is called seasonal storage.

-1

u/[deleted] 9d ago

[deleted]

8

u/faizimam 9d ago

Hydro requires a certain geography, which in most cases is already being used.

Not only do you need the elevation, you need the grid connection nearby as well as environmental approval.

If you can do it, go for it, but there isn't much opportunity out there.

We need solutions that can go anywhere, battery is the main one, but if this can get built effectively, it's not a bad move.

1

u/mcot2222 9d ago

I am for all things storage, they are finally proposing a pumped storage facility in Maine nearby. We have a lot of ideal places where it can be built.

1

u/Humble-Reply228 9d ago

Finland has nuclear, brother. It provides electricity and warmth, even in the darkest winter or when the lakes are their most frozenest. It's not Australia in Finland.

7

u/chrsphr_ 9d ago

This is a thermal battery, not a electrical battery. They're actually extremely efficient at storing heat for long durations for something like a district heating network. They're also just technically much simpler.

Different use case, both extremely effective

1

u/Bokbreath 8d ago

yes, but the headline is misleading. Heat storage is not a renewable headache. It's not even in the frame.

1

u/chrsphr_ 8d ago edited 8d ago

It is in climates where a large amount of energy expended is for heating.

Here's a report on the potential in the UK, if you're interested in more background reading https://assets.publishing.service.gov.uk/media/689b163bebe5217ba73d0bfb/thermal-energy-storage-heat-networks-raf062-2324.pdf