A new approach for comparability of two- and three-bladed 20 MW offshore wind turbines

Abstract

Wind energy plants are subject to a vast optimization process with a multitude of design parameters. While one specific three-bladed turbine type dominates the on- and offshore market, two-bladed turbines offer promising, but not yet quantified, potentials for cost savings during manufacturing, erection, and maintenance, offshore. Nevertheless, the comparability of two- and three-bladed turbines is challenging, causing an ongoing discussion within research and industry about which alternative to prefer. A new approach could be to reduce the important changes made by maintaining the exact same energy yield. This results in an increase of design changes of the two-bladed rotor, due to slightly (about 2%) longer blades to counterbalance the inevitable losses of aerodynamic efficiency. Nevertheless, it has the great advantage that subsequent comparisons of loads, masses and costs do not have to be associated with a loss of power. This could serve as a solid basis to allow drawing conclusions and considering differences in dynamical loads, masses and costs more directly and hopefully more expediently, when comparing two- and three-bladed wind turbines.