Efficiency of High-Altitude Wind Turbines in the Andes: Air Density and Turbulence Effects

The wind energy is one of the most important alternatives for renewable and clean electricity
generation. During the last decade, the number of wind farms has largely increased in South America.
Qollpana is only one case of a wind farm that is located at 2900 meters above sea level over a
complex terrain. Due to high altitude, the air density is reduced by 40% compared with sea level and
the topographic characteristics induce a high level of turbulence. Qollpana wind farm has two 1.5 MW
and eight 3 MW wind turbines reaching 27 MW of installed capacity and this project is important to
implement more wind farms at high altitude conditions of the Andes. The main results shown that
October is the month of highest wind average velocity and February with the lowest one. This work
analyses the capacity factor of the wind farm, also the air density and the turbulence effects on wind
turbine efficiency. The main results show that monthly capacity factor varies between 0.08 and 0.67 in
the wind farm. Moreover, the results have shown a considerable effect of the turbulence intensity on
the turbine efficiency. However, these conclusions are only valid for the period studied and we are still
working on the mesoscale and microscale meteorology of the region to enhance the knowledge and
the certainty of the efficiency of wind turbines under high altitude and complex terrain over the Andes.