Economic Aspects of Wind Turbine Aerodynamics

Abstract

Wind turbines are aerodynamically driven machines. The energy produced is chiefly associated with the efficiency of their rotors to convert the kinetic energy of wind to mechanical power. Still, mechanical power must be transformed to electrical through a drivetrain, and the whole system should be kept in place through a support structure. The selection of the proper architecture and the design of these three main subsystems (rotor, drive train, support structure) allow for much freedom, but at the end of the day, it is driven by economical aspects. The optimal turbine design for a given site (onshore/offshore) with known external conditions is the one which can produce electricity in the lowest possible cost, usually expressed through a metric called levelized cost of electricity (LCoE). We acknowledge the fact that since a few years, wind farms are subjected to variable market price mechanisms, and the value of the produced electricity is depending on the market specifics, possibly leading to a different optimum than the one suggested by minimum LCoE. As, however, LCoE remains a pure metric for technology assessment, the goal of this chapter is to make the connection between LCoE and technological selections and design aspects, with focus on rotor aerodynamics. Mastering this connection allows for better understanding the critical areas where the emphasis should be placed for improving cost-efficiency of wind turbine designs.