Climate change: 'Sand battery' could solve green energy's big problem [BBC]

[IcyPeas]

Finnish researchers have installed the world's first fully working "sand battery" which can store green power for months at a time.

The developers say this could solve the problem of year-round supply, a major issue for green energy.
....
The sand stores the heat at around 500C, which can then warm homes in winter when energy is more expensive.
....
One of the big challenges now is whether the technology can be scaled up to really make a difference - and will the developers be able to use it to get electricity out as well as heat?

The efficiency falls dramatically when the sand is used to just return power to the electricity grid.

More: (helpful diagram in link)

https://www.bbc.co.uk/news/science-environment-61996520

[muriel_volestrangler]

1. What surprises me is that the insulation can be good enough to be effective for months

I don't know if they go into more detail than:

Proper insulation between the storage and environment ensures long storing period, up to months, with minimal heat losses.

https://polarnightenergy.fi/technology

Perhaps that's their technological advantage - they figured out the combination of heat storage medium and container which conduct really badly.

[mitch96]

2. "Efficiency falls dramatically when the sand is used to return power to the electricity grid".

Maybe point of use sand battery? That would eliminate the transmission loss but would increase complexity. I think you would need some inexpensive method to convert the 500c heat to electricity. A thought..
m

[muriel_volestrangler]

3. No, this really is designed for heating, not electricity

500 degrees Celsius is a relatively low temperature for a heat source, and thermodynamics means you just can't get good efficiency from that - it's the conversion to electricity, not transmission to a grid that is the inefficient part. But space heating is a major energy use in temperate zones, and hot water everywhere, so there could be good uses for this.

[mitch96]

4. Good point. Sand "battery" for point of use heating.. It gets cold in Finland😁 nt

[Finishline42]

5. And there's this in Berlin

Hot water tank? They must have separate hot water supply lines there???

The tower, located on an industrial site near the banks of Berlin's Spree River, will provide heat to homes using a similar method to thermos flasks. It's roughly 150 feet (45 meters) tall and holds 14.8 million gallons (56 million liters) of hot water.

The new facility was unveiled this week, Thursday, June 30, at Vattenfall's Reuter power station. It will be Europe's largest heat storage facility once it's completed at the end of the year. It's worth noting that a bigger version is already planned for construction in the Netherlands.

According to the developer of the tower, utility company Vattenfall, it will heat Berlin homes this winter even if Russia cuts off gas supplies due to Western sanctions following its invasion of Ukraine.

https://interestingengineering.com/steel-thermos-tower-berlin-heat-storage-facility

[NNadir]

6. Unbelievable.

The schemes to save so called "green energy" - which is not sustainable in any sense - just get weirder and weirder.

There are probably thousands of thermal energy storage schemes published each year.

In fact, here's what Google Scholar found in 0.10 seconds on the subject.



3,360,000 hits.

Some journalist - probably one who didn't take many science courses in College, if any - picks one out of a hat and Whammo!

We're Saved!!!!

So called "renewable energy" is unsustainable precisely because of it's low energy to mass ratio. It's a failure, and the longer we search for band aids for it with undue credulousness, the faster things will get worse, and let's be clear, they are very, very, very, very bad. As the accumulation of the dangerous fossil fuel waste carbon dioxide has accelerated, now approaching 2.5 ppm/year, we are about 12 years away from 450 ppm.

We're saved?!?!

Unbelievable.