I have used them inside plenty of times when we have had power issues. I have a container with new ones that I bought marked down after Christmas on hand. Doesn't take much to power them up either. I also have some spaced across the top of my fence to have lights when I take the dog out, they easily weave in the fencing wire and it keeps the deer at bay away from the house (sometimes!) They do well in snow as long as there is some light to charge them for night.

Great idea.....