Towards a standard approach for future vertical axis wind turbine aerodynamics research and development

The development of Vertical Axis Wind Turbines (VAWTs) has continued for nearly half a century without agreement on a valid procedure for the design and testing of turbines, and it is clear that this has had an impact on the ability to bring a VAWT to commercial success. This has largely been due to analysis methods for their complex aerodynamics being either insufficiently accurate, or having very high computational time requirements, or the high costs attached with experimental testing. It has also been impacted by the previous conclusion that Horizontal Axis Wind Turbines (HAWTs) were simply the better option which has resulted in reduced investment into VAWT development. Computational Fluid Dynamics (CFD) analysis has now become the most common, allowing for a considerable increase in the amount of research that can be produced and enabling analysis of farm configurations, which has shown increases in efficiency, to the opposite of HAWTs. Many examples can be found which demonstrate complete disagreement between literature, and so this review has critiqued available articles and reports to create a consensus on how to test and design VAWTs from an aerodynamic perspective accurately and effectively. Recommendations for testing methodology, turbine and farm design have been produced.