The document provides an overview of various types of ocean energy resources including wave, tidal, ocean thermal, and salinity gradient energy. It notes that the theoretical global resource for wave energy is 8,000-80,000 TWh/yr, 800 TWh/yr for tidal current energy, and up to 10,000 TWh/yr for ocean thermal energy. This is a significant amount of energy that could meet or exceed current global electricity consumption of 17,000 TWh/yr. The document also describes some of the technologies used to capture these resources such as oscillating water columns for wave energy and tidal barrages for tidal energy.