Abstract— Due to environmental and economic concerns, there are numerous attempts to find more efficient and clean ways of generating electric power. High renewable energy penetration (wind energy) has increased. Renewable energy resources penetration into the conventional power grid is a challenging task. In this paper, the high renewable energy penetration impact on voltage and transient stability is studied by evaluating the nature of the relaying system needed, critical clearing time of circuit breakers, voltage level, and transfer capability between systems.