Wind speed forecasting is a crucial issue in the wind power industry. However, the disadvantage of the existing wind speed forecasting models is that they often ignore similar fluctuation information between the adjacent WTGs (wind turbine generators), which leads to poor forecasting accuracy. This paper proposes a hybrid wind speed forecasting model to overcome this disadvantage. Specifically, grey correlation analysis is applied to select useful fluctuation information from the adjacent and observed WTGs, and the chosen fluctuation information is fed into the v-SVM (v-support vector machine), which offers good capability in nonlinear fitting, to perform wind speed forecasting of the observed WTGs. Meanwhile, to reduce the impacts of the model parameters on the final forecasting performance, CS (cuckoo search) is used to tune the parameters in the v-SVM. The results from two case studies show that the proposed model, which considers the fluctuation information of the adjacent WTG, offers greater accuracy than the other compared models. As concluded from the results of three accuracy tests, the performances of v-SVM and epsilon-SVM (epsilon-support vector machine) show no significant difference, and the CS algorithm is more efficient than the PSO (particle swarm optimization) for tuning of the parameters in the v-SVM. (C) 2016 Elsevier Ltd. All rights reserved.