Work done is equal to zero assuming earth revolves around the sun in a perfect circle.

As Work=Force∗Displacement∗cosθ

Where θ is the angle between force and displacement .

In this case θ=90degree

As centripetal force is involved where earth is pulled towards the sun and direction of motion at each point is tangential to the orbit and as tangent makes 90degree with radius θ=90degree

Cos90o=0

Thereby F∗S∗cos90=F∗S∗0=0

HENCE NO WORK IS DONE .