  The flow speed-up generated by windbreaks can be used to increase the power
production of wind turbines. However, due to the increased drag imposed by the
windbreaks, their use in large wind turbine arrays has been questioned. We use
large eddy simulations to show that windbreaks can increase the power
production of large wind farms. A crucial finding is that windbreaks in a wind
farm should be much lower than for a single turbine case. In fact, the optimal
windbreak for an isolated turbine can reduce wind farm performance. The optimal
windbreak height in a wind farm namely depends on the right balance between
flow speed-up over the windbreak and the drag imposed by all windbreaks in the
farm. The increased performance is a result of the favorable total pressure
flux created by the windbreaks.
