You Do Need power plug adapter while traveling from Bahrain to Greenland.

Here is Why You Need An Adapter

The outlet and plug type used in Greenland are C, E, F and K and in Bahrain is G. This is how they look like.

Bahrain

In Bahrain, outlets of type G are in use.

Type G

Greenland

In Greenland, outlets of type C, E, F and K are in use.

Type C

Type E

Type F

Type K