You Do Need power plug adapter while traveling from Guinea 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 Guinea are C, F and K. This is how they look like.

Guinea

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

Type C

Type F

Type K

Greenland

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

Type C

Type E

Type F

Type K