Anybody doing any work with Phase Change Materials in thermal storage these days?

I saw one company that had it at the Tampa show.  As you mentioned they had the staple up material but also had materials that could range from -40F to 300F with no limit on cycles.  I've use salt hydrates but they have limited cycles, tend to segregate and can supercool.  They claim they've licked all the problems.  Just seeing if anybody has used them.  Thanx for yr response.   Fh

I haven't seen any that work well and are cost effective as compared to non phase change storage. Other than ice (for off peak AC).