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Nah, that’s not true if you use a container with cheap enough cost per storage-kWh, for instance salt caverns. In fact we ALREADY use them for seasonal natural
by Robotbeat 5y ago
Nah, that’s not true if you use a container with cheap enough cost per storage-kWh, for instance salt caverns. In fact we ALREADY use them for seasonal natural gas storage. The references to this toy model show how to get extremely low cost per storage-kWh, as cheap as 0.7 € per kWh. (So amortized over 20 years, that’s a pretty small addition to the energy cost). https://model.energy https://model.energy
Details on the salt cavern hydrogen storage: https://doi.org/10.1016/j.energy.2018.05.059 https://doi.org/10.1016/j.energy.2018.05.059
Or think in context of this liquid air (or compressed air) battery.
If you can get liquid air or compressed air batteries to cost $300/kWh or so, hydrogen in the same container compressed to the same degree can store about 100 times the energy (especially if sub-cooled). So the storage cost (if dominated by the container structure) drops by a factor of ~100. That’s $3/kWh for storage, if you don’t use salt caverns. Not great if only amortized over 20 years (plus the bad round-trip efficiency), but also not terrible if it’s only used for like 5% of the electricity needs.
And that’s the real issue with seasonal storage: no one needs it really until you get to 95-100% decarbonization of the grid. Otherwise, best to use like a few gas turbines or something as backup/seasonal power. So investing a bunch of storage when you haven’t even built out a bunch of solar or wind, yet, is kind of suboptimal. Good to do demo plants, though, so you can get ready with the tech for when you DO need to decarbonize that last 5% or so.