The electric fields engendered by winds of gravity wave origin are theoretically calculated for the dynamo region of the equatorial ionosphere. A general expression for the efficiency parameter, which is a measure of the effectiveness in producing the total electric field, is derived for a two-dimensional case, and the results are compared with those obtained from the one-dimensional treatment of the problem by Kato (1973). The efficiency parameter evaluated by Kato (1973) at the center of the electrojet is higher by about a factor of 5 than that computed here, owing to some apporoximations made by him. The dependence of the efficiency parameter on the horizontal scale size of gravity wave wind and the effectiveness of the east-west wind shear in producing the electron density stratifications are discussed.