I agree. There are pics of three prototypes here though: http://watersturbine.weebly.com/waters-turbine.html
Reading the text we see that wind velocity and pressure profiles have been taken! There is verbosity, but what is conspicuously absent is simple electrical power output. But, they have put the axle under load :
There are comparisons to a conventional turbine:
I would think this should depend very much on the gearing system, not just on turbine design.
My suggestion to Mark G: forget new prototypes for now. Just ask that they attach a gear system and generator to what they currently have. It ultimately has to be done anyway. Frankly, putting this off is avoidance of a likely mediocre outcome imo.
Display More
O dear, it is the same mistake we often see, experimenters confuse torque and power and efficiency.
"
Comparing my 4' design against a stock 5' three blade, under the same load, the conventional product starts at over 7 mph and produces very little torque or rpm at that speed. My turbine, under the same load starts at under 1 mph. If the square force relationship is used, that is 49 times more force required to turn the conventional design.
"
To get the power he needs to multiply torque in NewtonMeters with the rotational speed in Radians pr. Seconds.
Different wind speeds and different torque applied will then result in different rpms and then generate datapoints which will indicate a maximum power curve at various wind speeds.
Now compare this with the maximum energy of the wind = 0,5 * air density * wind area covered by the turbine * wind velocity ^3
The wind area is just the PI * the waters turbine radius ^2
To CONCLUDE: comparing torque of a propeller wind turbine with the waters turbine tell nothing more than which turbine is easier to start, and the lower velocity range.
But 14 mph is only 6 m/s speed, not much energy in the wind at these wind speeds...
A 5' turbine will then cover a wind area containing 200 Watt theoretical energy.
If it converts 80% of the Betz limit we get 93 Watt power.
Now prove that a Waters turbine are able to produce 93 Watt at 6 m/s.