This is interesting, and in my opinion definitely deserving of the prize they got for it.

But I think it's real value (in contrast to "replacing A/C") is in developing markets, where a little wristband could really improve quality of life (in the sense that one isn't sweating to death in their shanty-town hut). Not only could it improve QoL, but it would also be much cheaper to install than a central air unit, and also much more feasible: everyone has a wrist, not everyone has an insulated home with consistent electrical service that could provide the power for a central air unit. Cool stuff!