**Abstract**

The use of vertical axis wind turbines (VAWT) in Colombia could tackle the energy distribution difficulties as large parts of the territory are not connected to the electrical grid. The present chapter explains how to design and select an accurate VAWT for a mountain site, (the Chicamocha's canyon) by characterizing the wind energy potential, selecting the appropriate blade's airfoil, and design its corresponding blades to obtain an accurate VAWT performance. This methodology can be used to design and allocate a VAWT for residential use, as it tackles the critical point on wind energy design and selection. It is found feasible the use of wind energy at the location where the mean year density power is 485 [W/m<sup>2</sup> ], and the DU06W200 airfoil is suggested as its aerodynamic efficiency (*cl=cd*) overcomes by 14% the commonly used NACA0018. Finally, straight blades are recommended to overcome the inertial effects of the low wind velocity at the location.

**Keywords:** VAWT, Colombia, wind, energy, turbine

## **1. Introduction**

There is a need of developing wind energy solutions capable to adapt fluctuating flow resources to have a diversified energy portfolio for the energy demand in Colombia [1]. The Chicamocha's canyon topography does not allow a stable electrical grid, which difficulties the incentives for tourism and commodities at the location, and the local community needs a sustainable source of energy that does not impact the environment. Therefore, this work assembles the feasibility for installing Vertical Axis Wind Turbines (VAWT) along with an optimal design.

The performance of a VAWT relies principally on its airfoil and blades, which generate lift and drag forces that take advantage of the wind kinetic energy to produce torque at the shaft of the turbine. The airfoil design and selection is an important task that depends on three main topics: wind flow conditions, airfoil shape, and modeling. The Darrieus VAWT blades design are based on lift aerodynamic forces and commonly use the commercial NACA0018 airfoil, and its performance varies according to the wind velocities [2]. Claessens [3] developed the DU06W200 airfoil for VAWT turbines, which overcomes the aerodynamic performance of the NACA0018 under high wind velocities than the calculated at Chicamocha's Canyon nature. Yarusevych and Boutilier [4] analyses a similar

Reynolds number but only one angle of attack is analyzed. Therefore, Garcia Rodriguez et al. [1] complements previous studies by increasing the range of Reynolds numbers analyzed for the DU06W200 airfoil, providing further information about the aerodynamic global coefficients and analyzing the performance of both airfoils under different attack angles.

In addition, different geometrical factors related to Power Coefficient *Cp* and VAWT turbine design is presented. These parameters vary depending on the wind characteristics of the region where the turbine is installed, therefore its analysis is fundamental to determine the VAWT performance. The 3D analysis performed allows an accurate VAWT dimensions distribution, correlates literature wind speeds (between 4 and 7 m/s) works with the Chicamocha Canyon region. Finally, different the influence of the VAWT turbine blades design is analyzed, by characterizing the Savonius rotor, Troposkien design, straight blades helical blades, observing the advantages and disadvantages of each type for the conditions of the region in question.
