A system employs wave energy harvesting apparatus and a water vessel (e.g., a ship) carrying an energy storage apparatus (e.g., array of batteries). The energy harvesting apparatus is preferably also carried by the water vessel, but may be fixed or carried by a separate water vessel. The water vessel is operated in an energy storing mode at an energy harvesting location subject to wave activity, during which the energy storage apparatus stores energy from the wave activity as harvested by the energy harvesting apparatus. The water vessel is operated in an energy transporting mode to transport the stored energy from the energy harvesting location to an energy releasing location (preferably onshore, but may be offshore) having a connection to an electrical power grid. The water vessel is operated at the energy releasing location in an energy releasing mode in which the stored energy is transformed into appropriate AC electricity supplied to the electrical power grid.