For the past few years, interest in wave energy is growing very fast. The ocean holds massive amount of clean and untouched energy, which can show an important role in supplying our energy demand. It is approximated that total energy from the coast of the United States is 252 million MWh/year. Oceans and sees around the world contain plentiful amount of energy that exceeds today's power generation needs. Wave Energy Converters (WEC) are devices to convert wave energy into electrical energy. One example of WEC technology is Oscillating Water Columns (OWCs). OWCs are devices with a semi-submerged chamber or hollow open to the sea below, keeping a trapped air pocket above a water column. Waves force the column to act like a piston, moving up and down, forcing the air out of the chamber and back into it. This continuous movement force a bidirectional stream of high-velocity air, which is channelled through a Power-TakeOff (PTO). The PTO system converts the airflow into energy. This paper discusses different types of wave energy converters and challenges regarding their integration to power grid.