This study investigated the transient energy affection by grid-connected wind farm under lightning. Modeling of the energy system with grid-connected wind farm for Electro Magnetic Transients Program (EMTP) was established efficiently to simulate the transient phenomenon of energy distribution during lightning. The transient phenomena caused by lightning strikes on wind turbines connected to a power system were simulated through three different cases. From the simulation and analysis results, a number of informative suggestions and strategies can be provided to minimize or prevent the possible affection of wind farms and the connected power system during lightning. (C) 2012 Elsevier Ltd. All rights reserved.