The paper presents research to develop a model complex that takes into account the interaction between the wind farm and the atmosphere, and between closely spaced wind farms. Six models have been reviewed and developed/adapted for use in wind farm modelling, covering scales from several hundred kilometres down to the size of the individual wind turbine. Flow within wind farms is difficult to predict. The analytical and modified WAsP/park models show promise; however, these require further development/evaluation. For the flow downwind of the wind farm, several intermediate-scale models fit the available data rather well, and may be candidates for the other half of the two-model complex which we aim at building. Copyright © 2009 John Wiley & Sons, Ltd.