A drive shaft is supported at first and second ends with bearings for rotational reciprocation. A sail has a fixed portion and a reciprocable portion. An inextensible cord couples the reciprocable portion of the sail to the drive shaft adjacent to the first end whereby wind contacting the sail will reciprocate the reciprocable portion of the sail to pull the inextensible cord and rotate the drive shaft. A generator is rotatably coupled to the drive shaft adjacent to the second end for creating electrical energy in response to the reciprocation of the sail from the action of the wind.