Maximum Power Coefficient Analysis in Wind Energy Conversion Systems: Questioning, Findings, and New Perspective

Abstract

For decades, maximum power coefficient limit, known as the Betz limit, has been accepted as a theoretical optimum value for wind turbine power extraction; nevertheless, some reports, exceeding this limit, have already been published. To explain this phenomenon and show a different point of view, a novel theoretical and ideal analysis based on flow conservation law and areas’ quotient is presented, supported by a review of works related to surpassing the power coefficient limit approached from different perspectives.

Energy Generation Intensity (EGI) of Solar Updraft Tower (SUT) Power Plants Relative to CSP Plants and PV Power Plants Using the New Energy Simulator “Aladdin”

“…It is subject to a theoretical limit of 16/27 or 59.3%, known as the Betz limit [87,88] for conventional open wind turbines. However, this limit can be exceeded for ducted (shrouded) wind turbines [89,90], which is the case in SUTPPs.…”

Mathematical modeling of vertical axis wind turbines

“…The Betz theory was developed on the example of a wind turbine which have a horizontal axis, according to [4][5][6] the use of this coefficient for a vertical axis wind turbine can cause inaccuracies in the calculations. There are many types of vertical axis turbines [7], so the power factor in such turbines should be determined based on experimental results [8]. In addition, the efficiency of the electric generator ( ) also impact of the output power of the wind farm [9].…”

Exploring the Potentials and Challenges of Renewable Energy Sources

“…Furthermore, the maximum achievable amount of wind power consumption in a wind turbine is defined by the Betz limit and Betz rule, which is 59.3%. It is not now possible for any advanced wind turbine to achieve energy efficiency greater than the specified 59.3% [18]. Wind power facilities are only able to harness less than 50% of the wind's kinetic energy into usable electricity.…”