Today, the environmental impact of connected objects is very important to me, the use of massive batteries is not common sense.
I would like to know if the use of alternative energy has already been used in projects with IMP electric modules, for example photovoltaic, etc.
Yes, there are people running imps from solar/battery combos. Some commercial products did this (eg there was a commercial plant water monitor that ran from a 2" square solar cell).
All imps (with the exception of the imp005) can be configured into very low power consumption states so it’s not hard to fit within low power budgets.