You Do Need power plug adapter while traveling from Solomon Islands to South Africa.

Here is Why You Need An Adapter

The outlet and plug type used in South Africa are C, M and N and in Solomon Islands are G and I. This is how they look like.

Solomon Islands

In Solomon Islands, outlets of type G and I are in use.

Type G

Type I

South Africa

In South Africa, outlets of type C, M and N are in use.

Type C

Type M

Type N