TECHNOLOGY: Design Philosophy
There are several methods in use today to convert the current flow of rivers and oceans into useful mechanical power. Many of those methods involved convert the linear motion of the current into rotary motion through the use of hydrofoils and turbines.While in themselves hydrofoils and turbines are by no means inefficient in the conversion of linear forces to rotary forces, they are limited in scope and breadth, due to their very nature of having a horizontally rotating axis. This means that the hydrofoils and turbines are located on a vertically-oriented rotating disk (with a horizontal axis) and are therefore limited in diameter by the depth of the water in which they operate. Since power is the product of torque and speed, and the speed of rotation is limited due to the generally slow pace of the water current, the only way to build a high-power generator is with large torque, and vertically rotating generators cannot provide that torque due to the limitations in water depth.
Other attempts do deal with this issue include generators whose turbine blades move faster than the speed of the water, but this rapidly introduces new complications to safe and reliable operation. In particular, due to their very nature, hydrofoils and turbine disks have numerous blades with narrow leading edges. Because the blades move faster than -- and are normal to -- the water current these blades can cause severe damage to any living organism that is impacted by them during normal operation. These issues can be mitigated with screens or inlet restrictions, but such solutions are imperfect, as, for example, fish and other such organisms are trapped against the screens.
Furthermore, because hydrofoils and turbine blades must operate at faster-than-nominal current speeds, they must often be accompanied by additional man-made structures and flow restriction devices such as a dam, flue, conduit, duct or pipe (used to increase current velocity). This severely adds to the expense of the project, and limits the locations at which this technology can be deployed, while impacts the local aquatic species and environment in an adverse manner through construction and habitation damage. In many cases it also exposes portions of the construction to the elements and accordingly presents hazards to navigation. At the present time most other technologies are not only severely limited in where they can be placed, but disrupt and damage the environment and impede surface traffic to an unacceptable level, often causing permanent adverse effects to the ecosystem.
With the advent of a submerged, horizontally rotating hydrokinetic electrical generator, we have a solution that is unrestricted as to where is can be placed and operated, and posed to ecological danger due to faster-than-current components. This device is totally submerged and needs no additional structures or restrictions for its normal use; it is benign to the environment in which it operates, whether inland or offshore. Most importantly, this device is only restricted in rotational diameter size by the width of the waterway -- not the depth. This allows for significantly more power to be derived from a self-contained hydro-powered device operating in an unimpeded water current.
More specifically, this generator was designed and sized to be submerged alongside existing on-shore power plants so that the electrical power derived from the device can be routed directly into the on-shore power station thus reducing or eliminating its dependence on its existing fossil fuel source.