According to new research published by Carnegie's Enrico Antonini & Ken Caldeira in Proceedings of the National Academy of Sciences, it is all about location, location, location.Turbines turn wind's kinetic energy to produce electrical energy. The very act of installing turbines can affect our ability to harness wind's power. The wind is affected when a turbine interacts with it. The ability of one turbine to extract energy from wind affects the ability of its neighbours.Antonini stated that although wind is not going to run dry as an energy resource, it can be harvested in a limited way. Wind turbines that are placed in large numbers can reduce their efficiency and the speed at which they extract energy.Caldeira and Antonini set out to determine the maximum size of a windfarm before it exceeds its capacity per unit of land. They also wanted to know how big large farms can cast a "wind shadow", which could have a negative impact on downwind installations.Caldeira stated that wind farms could provide as much as one third of the global energy supply by 2050 if we abandon fossil fuels. It is crucial that we know the relationship between turbine placements and maximum energy extraction.After some of the wind's kinetic energy has been extracted from a wind farm, it takes time for wind to recover to its normal strength. Antonini and Caldeira stated that the speed at which wind recovers from being struck by a turbine depends on its latitude and Earth's rotation. Studies on wind power generation in the past have shown large wakes. Therefore, Antonini and Caldeira created a theoretical understanding of how these wakes are controlled.The speed of wind and the time it takes for pressure differences to restore the energy extracted by the turbines determine the size of large wind farms' wakes. These factors must be taken into consideration when placing wind farms in different locations.They found that turbines located in high wind areas are more susceptible to being affected by upstream neighbors than those situated in lower winds areas. Wind farms closer to the Equator are more susceptible to being negatively affected by upstream wind farms' wind shadows than those closer to the poles.Caldeira stated that wind energy could be a source of large amounts carbon-emission-free electricity. "But, to make the most of this resource, it is important to consider how other wind farm might affect us and how we might impact other wind farms."The authors suggested that multiple small wind farms, with space for wind recuperation in between them, could be more efficient in certain locations than one large wind farm. However, more research is necessary.Antonini stated that he hoped the work would enable managers and builders of wind turbines to create the most favorable conditions for maximum wind power generation.
