This chapter provides a novel approach of network resiliency analysis of the power grid, employing complex network framework-based percolation method. An effi- cient algorithm is used to assess the vulnerability of the Australian power grid with large-scale renewable generation capacities. Our analysis finds that, although renewable energy have many advantages, and the target is to incorporate more and more renewable within the grid, but increased penetration caused vulnerability in a greater scale. Also, it is found that betweenness-based targeted attack reduces the functionality of the system to a great extent. Preventive measures should be taken so that critical components could be protected in order to ensure secure operation of the power grid.