All wave power systems operate on the principle that moving water carries a substantial amount of energy, transferred from wind to the water by well understood physics. In principle, there is a very large wave power resource, estimated to be roughly 2 TW, but is it highly localized to certain parts of the globe (e.g. north-west Europe, north-west Pacific). There many different potential wave energy converter designs that use different methods to capture wave energy. Versions of wave energy conversion systems include: - A point absorber buoy uses the rise and fall of swells to generate power, using a linear, linear to rotary, or hydraulic generator. - A surface attenuator has multiple floating segments that translate the wave motion into a mechanical bending motion that turns a generator, either directly or through hydraulics. - An oscillating wave surge converter is attached to the sea floor, and the up and down motion is used by various means (e.g. floats, flaps, pistons) to make electricity. - An oscillating water column uses the up and down energy of the wave to compress air, which is then used to generate electricity via an air turbine. - An overtopping device essentially creates a small hydro dam from waves transferring water into a storage chamber with a turbine. - Submerged pressure differential devices typically use a flexible membrane to capture the pressure differential induced by waves at various depths, transferring this energy to a hydraulic fluid. They can be near the surface, mid-depth or on the ocean floor, and can be moved and adjusted with incoming waves. Wave power is at a much lower level of technical development compared to solar PV, onshore wind, offshore fixed wind, and offshore floating wind, all of which will capture most near-term investment and cumulative global economies of scale and innovation.