Wind loads, known to be an essential factors in the design of structures for photovoltaic arrays, are the products of kinetic pressure, wind-force coefficient C_W and array area, under JIS C 8955. However, the use of C_W is limited to an array angle-of-attack θ between 15° and 45°, and is not applicable where angle-of-attack is low at approximately 10°. However, such low θ have been used increasingly in recent years. In addition, the impact of the difference in the distance from the ground to array has not been investigated. When objects having a wing-form shape are moving close to the ground, a ground-effect may arise, resulting in an increase in lift power, and a similar increase is expected for arrays that have shapes similar to wings. If these wind loads can be evaluated properly, it is expected that the safety and economical performance of arrays can be further improved. In this research, the authors conducted a wind tunnel test using a 1/20 single-unit scale array model to estimate and refine wind-force coefficient C_W taking into account the array's angle-of-attack and its structure height.