Transmission topology control is a tool used by system operators in the role of a control action taken into account as a preventive or corrective action relative to a specific outage or set of outages. However, their inclusion in most electricity market frameworks is limited. With the increasing penetration of intermittent energy sources, optimal topology can be used as a lever of flexibility to decrease the total system cost. This paper demonstrates the evolution of optimal topology control on systems with increasing quantities of intermittent renewable energy along two axes. First, the effects of the increased variable sources on the variations of optimal topology are explored. Second, we elaborate on the growing advantages of exploiting transmissionlevel grid flexibility in terms of total system cost. Case studies are performed on a modified RTS-96 network.