You Do Need power plug adapter while traveling from Balearic Islands to Niger.

Here is Why You Need An Adapter

The outlet and plug type used in Niger are C, D, E and F and in Balearic Islands are C and F. This is how they look like.

Balearic Islands

In Balearic Islands, outlets of type C and F are in use.

Type C

Type F

Niger

In Niger, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F