Alphabet spinoff Malta raises $26M for technology to store power in molten salt
The rather extreme losses associated with electricity > heat > heat engine > electricity seem like an absolute deal killer. Assuming they are at an extreme 50% round trip efficiency you need to be extremely cheap to have a hope of breaking even.  Worse heat has fairly low energy density and cools over time so they can’t really scale the up or down that much.<p>It might be possible if they where starting with heat, but feeding this from wind and solar just seems unlikely.