You Do Need power plug adapter while traveling from Palestine to Tuvalu.

Here is Why You Need An Adapter

The outlet and plug type used in Tuvalu is I and in Palestine are C and H. This is how they look like.

Palestine

In Palestine, outlets of type C and H are in use.

Type C

Type H

Tuvalu

In Tuvalu, outlets of type I are in use.

Type I