One of the potential hindrances to ubiquitous Internet of Things (IoT) take-up is related to how one should power the possibly billions of tiny sensors promised over time. Can one expect a homeowner to change out a hundred or so coin batteries every few years in, say, a networked system, for example? That could get old fast.
The same problem arises at an industrial level. Changing out sensor batteries in a remote installation is equally difficult to achieve, although for different reasons — you need to transport expensive people there to do it, for one thing.