This paper presents an adequacy evaluation scheme based on the Monte Carlo method, aiming to quantitatively evaluate the capacity-replacement contribution of wind energy. The paper first proposes a new wind generation unit model that consists of wind, wind turbine and wind farm. It then describes the wind speed correlation of different wind farms and carries through a Monte-Carlo simulation to get the anticipated reliability indices. Finally, the validity of the proposed model and algorithm is proved by an analysis of the selected sample system.