HAWT contra VAWT ?

Today a new discussion has flared up on the topic: Horizontal Axis Wind turbine (HAWT) versus Vertical Axis Wind Turbine (VAWT). This unnecessary dispute is as old as even the utilization of windenergy by mankind.

The German Foundation for International Development at the Seminar Centre for Economic and Social Development (DSE) has organized at Berlin (Germany), 1975, an "International Conference: Appropriate Technologies for Semiarid Areas: Wind and Solar Energy for Water Supply".
In the proceedings of this conference you can find the paper:
"Efficiency and Economic Comparison of Different WEC-(Wind Energy Converter)
Rotor Systems", presented by H.H. Doerner.

Here you will find a pdf-file of the named paper.
click click

This paper figured out:
Click Figure 1. Build up with a certain area of material the largest plant possible (figure 15 in the above mentioned paper) to reach the biggest swept area, through which energy can be extracted out from the airflow.
Click Figure 2. Here you can see the different machines for the same output at a certain windspeed. The rotor with the least material expense is the most economic. A defined quality number Q shows clearly the superiority of the HAWT to the other examined systems (Figure 16 in the above mentioned paper).

To play fair, the comparison has made some simplifications.
- only the aerodynamic parts (rotors) of the different systems have been taken into account
- only a certain value for the mass for the squaremeter material of the rotor was assumed, not looking to the structure, the strength, the stiffness, the forces, a.s.o
But nevertheless, the results are generally O.K.
Supplementary, for example you may have a look to the needed tower structures for the different systems. . .

doerner@ifb.uni-stuttgart.de Since 21th of mai 1997