Lighter-Than-Air Wind Energy Systems

Several wind energy concepts utilize airborne systems that contain lighterthan-air gas, which supplements aerodynamic lift and expands these systems’ available operating regimes. While lighter-than-air systems can incorporate the traction and crosswind flight motions of their heavier-than-air counterparts, several lighterthan-air concepts have also been designed to deliver large amounts of power under completely stationary operation and remain aloft during periods of intermittent wind. This chapter provides an overview of the history of LTA airborne wind energy concepts, including the design drivers and principal design constraints. The focus then turns to the structural and aerodynamic design principles behind lighterthan air systems, along with fundamental flight dynamic principles that must be addressed. A prototype design developed by Altaeros Energies is examined as an example of the application of these principles. The chapter closes with suggestions for future research to enable commercially-viable LTA systems.