>But these systems are great for providing long term energy storage for e.g. heating systems needed in the winter. Yep, that's how I first heard of it. Finnish

>But these systems are great for providing long term energy storage for e.g. heating systems needed in the winter. Yep, that's how I first heard of it. Finnish company providing sand-based thermal energy storage: https://newatlas.com/energy/sand-battery-polar-night/ https://newatlas.com/energy/sand-battery-polar-night/ For electric generation, there's this Danish company whose system integrates turbines run off reheated air: https://www.stiesdal.com/storage/the-gridscale-technology-explained/ https://www.stiesdal.com/storage/the-gridscale-technology-ex... They claim to be deploying a 4MW demonstrator unit sometime this year. As I imagine it, a system like this one could charge smaller (in-home) batteries that provide immediate power on demand. As the batteries begin to drain, the turbine has time to spin up. The chemical batteries act as a buffer for turbine downtime and/or response time. Sort of like a Prius hybrid powertrain. The required chemical battery capacity would be much smaller than, say, a grid-scale lithium ion battery bank.