Robert Whittlesey and John Dabiri, two fluid dynamicists from the California Institute of Technology in Pasadena, have discovered that arranging vertical axis wind turbines (VAWT) in a certain pattern will save the space by 100 times compared to classic arrangements, will output the same amount of energy and will be safer for migrating birds.
The discovery was based on the observation that even if it’s about Lance Armstrong riding behind his teammates to save energy, a pack of fish staying closer together to slice the water, or birds flying in their well-known patterns, the leader is the one who pushes harder, making it easier for the rest to follow, because of the reduced drag.
If we’re talking about HAWTs (horizontal axis wind turbines), the opposite happens: they need a large area between themselves, because turbulent wind breezes created by the leading turbine’s blades can’t propel the trailing blades as well as an unobstructed flow. This is the reason HAWT fields are so spread, so the wind can recover and hit the next turbine without any “air holes”.
The researchers also found out that the most efficient arrangement was one that was alternating the rotational direction of the VAWTs. The lead turbine should have a clockwise rotation, followed by two counterclockwise in line, followed by three clockwise turbine, etc. Whittlesey says that the study is only basic at this time, and further research will improve the model.
As for the birds safety, he says: “the faster they spin, the more solid they appear,” thereby allowing birds to see the turbines more easily and navigate around them. Well, that’s discussable, but it’s a start.