TECHNOLOGY: How It Works
The equations that determine the power output capability are unique to HyPEGs, as they do not behave like conventional underwater turbines. The total output capability of the HyPEG is determined by the differential in Form Drag (Fd) between the 'Retreating' side (the cups going with the current) and the 'Advancing' side (cups going against the current). The difference translates into rotary torque and the power output is based on this torque.
These formulas are based on the accepted hydrodynamic form drag formulas for non-compressible flow of solid bodies in a steady current, i.e. the same formulas the US Navy uses to determine the power required to move a submarine. But they do have some peculiarities.
These peculiarities are most apparent when you factor in the Coefficient of Drag (Cd) for each side, and the drag on the Advancing cups is a factor of twice the river current because they are moving against the current, not with it. What makes HyPEGs so powerful is that the Retreating cups maximize drag (to create massive torque) and the Advancing cups fold against the wheel to minimize drag. The difference can be astounding. In unrestricted river and ocean currents HyPEGs are capable of producing more than 25 times the amount of power than a single turbine with a blade area matching the cup size on the HyPEG.
Simply put, for whatever diameter of underwater turbine that is applicable for any given current, a HyPEG at the same depth (and with the same ‘profile’ area to match) will produce 25 times more watts and do it at ½ the cost per watt, but not kill the fish swimming around it.
Inventer Video Interview The inventor of the HyPEG system was interviewed in September 2009 by Grassroots Television in Tennessee. That interview is now available for viewing on this web site, as well as on Blip.TV.