yeah its not doing the project any favors is it.

They've only built two of these things in production. I think it's okay to use forecast costs when it's this early. I assume they'll get better at this, production gets cheaper and the bulk of the material will actually be a logistics cost rather than materials, so putting sticker prices on these might not translate well.

But the "smaller prototype" is 8MWh. Their estimate of $25/kWh would make that $200k, and this 100MWh unit should scale to $2.5M but there have already received many times that in funding. Who knows.

I don't think lithium ion is even the right comparison in this case. This could more comparable in spirit, although 900 times bigger in capacity and not yet finished. https://www.vantaanenergia.fi/en/about-us/projects/varanto-t...

If you try gauge the price from that cavern storage (estimated 200 million euros) then lets say it has some economies of scale, maybe this sand battery costs like 500k-1M euros.

If you just heat the storage on cheap hours and output at high prices. You could in theory cycle (24*365/2) hours at 1 MW so 4,4 GWh of energy per year. So how could be the project profitable?

In 10 year period with full utilization price differential would need to be 22.8 €/MWh to break even with 1M investment, then add operating costs, loan interest, etc. With more realistic utilization it would need to even higher.

Maybe you amortize costs over 20, 30 years. But its's even more uncertain what cost of electricity will be. I think it only makes sense if this storage allows them to electrify heat production replacing much more expensive current production.

That and the downsides to the sand battery. We don't need more biased new stories trying to promote everything as miraculously pure-good. Environmental concerns hardly matter for utility energy generation because if it's not cheaper, it will will either completely fail or be a tax on everyone if the government mandates it.

The obvious problem is it can only really be used for heating, not electricity. But heating is still a fine use when available.

is it actually "big" in Aus?

I know MGA Thermal have a demo project that the gov funded, but is there anything in commercial use?

"It is true that we have been trying to avoid the word battery, since technically speaking it is not what we have. Anyhow, the word caught fire, and was a big part of the media success, and it probably was McGrath’s invention. Of course if we were to generate electricity from the heat, it would at least act like a battery does: taking in electricity and giving back electricity."

(2022) https://www.treehugger.com/viral-sand-battery-isnt-what-it-s...