Sign up for daily news updates from CleanTechnica on email. Or follow us on Google News! The other day, I published my doorstop assessment of the thermodynamics and operational challenges that limit compressed gas storage solutions, pushing them into the 100 GW of also-ran capacities. In comments in various places, people reminded me of the long-defunct LightSail and the now-getting-press Hydrostor. A bit of followup with some comments and assessments on them seemed worthwhile. As a reminder, th...