NOVELTY - The method involves positioning a tubular member associated with an offshore facility in communication with water, where the tubular member has an opening for waves from the water to enter in exit the tubular member such that inward/outward flow of water raises and lowers water level in the tubular member to define an oscillating water column within the tubular member. Pressure changes in air above the column are utilized to drive a turbine that is coupled with an electric power-generating device to generate electric power. The electric power is used to power devices on the facility.    USE - Method for producing electrical power from renewable wave energy for an offshore facility e.g. offshore oil platform and floating vessel (all claimed) such as floating production storage and offloading (FPSO) vessel, using fossil fuel-driven power generating equipments e.g. small-scale diesel generators such as solar panels and single-stage/multi-stage turbines e.g. micro-wind turbines, and low-head hydro-air turbines such as wells-type turbine. Can also be used for an offshore gas platform, offshore hydrocarbon facility, exploration and production facility and an equipment.    ADVANTAGE - The method enables the turbine to be positioned in legs of the offshore oil/gas platform, so that the leg is modified with an external plenum, thus increasing flow volume to the turbine inside and outside of the leg. The method enables utilizing the pressure changes in the air above the column to drive the turbine that is coupled with the electric power-generating device so as to generate electric power for the offshore oil/gas platform. The method enables compressed air from an accumulator to increase efficiency of the turbine on the platform by boosting intake air pressure and temperature.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a system for producing power from wave energy for an offshore facility.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of an offshore facility.