The OBREC device consists of a concrete top element, which can be installed in new or existing breakwater, e.g. during maintenance operations. It is provided with a sloping plate that conveys the overtopping waves inside a reservoir, which later flow in the rear chamber, where the turbines should be installed. The front reservoir captures the overtopping waves to produce electricity. The energy can be then extracted via low head turbines, which should be powered by a constant hydraulic head.