The picture shows a millrace feeding a prop which spins slowly with a high torque, allowing the passage of fish down through the prop. I do not expect fish to swim up through the prop, but it is only one meter and less likely things sometimes work. More likely, and what is shown in the drawings on the home site is a bypass channel that can obviously be replaced by a fish ladder to reduce wastage.
Most important is that a fish can swim past this system up stream. On top of that, the system as illustrated can obviously be stacked as a double silo to any necessary height. This means we have a feasible way to allow migrating fish to bypass a tall power dam safely.
We currently are trucking fish past dams and it unsatisfactory. Here we have a solution that also produces power to support its upkeep.
This directly solves the problem of sharing a salmon fishery with dam. We still have to work to maintain appropriate streams and gravel washes but that is the easy part that needs regulation and a little care. This promises to even be beneficial to the salmon since a dammed river system has eliminated most of the natural hazards and has opened up ample potential spawning beds and rearing areas
Capturing the Power of Whirlpools
Written by Philip Proefrock
Monday, 19 January 2009
An Austrian engineer, Franz Zotlöterer, has developed a new method for small scale hydropower by creating a whirlpool that avoids many of the problems typically associated with hydroelectric generation.
In terms of green power generation, solar and wind get much of the attention. Hydropower is as green as wind and solar in terms of limiting emissions, but some of the ecosystem disruption associated with large-scale hydro have taken it off the table as a choice for good green power. However, smaller scale hydropower options can provide electrical power and provide additional benefits to the waterway.
The original idea behind the vortex was, in fact, not power generation, but water purification. A vortex in the water serves to efficiently aerate the water and to aid in more rapid breakdown of contaminants.
The idea to use a continuous, strong vortex flow actually occurred to Franz Zotlöterer while trying to solve the inherent problems with water quality of the natural swimming pond he had set up in his own garden. He finally decided to build a small rotation basin to aerate the water – and it worked. He then began to think about other potential fields of application for his aeration concept: drinking water supply, wastewater treatment, electricity generation. - Aquamedia
Instead of channeling the water directly through a turbine, vortex hydropower creates a spinning vortex, and draws energy from the swirling water. This approach makes it possible to generate energy without completely blocking the waterway and eliminates the need for much screening or filtration. Small debris is not a problem for vortex generation as it would be for a conventional turbine. Furthermore, fish are able to pass by the vortex chamber without harm. The vortex operates at slower speeds, and the large open chamber makes it possible for fish to pass even going upstream. The vortex also reduces the temperature change of the water, and can more readily be integrated into the natural river environment.
The pilot plant only needs a fall of 1.3 meters (4.25 feet) and, with a flow rate of 1 cubic meter per second (about 265 gallons per second), produces 8 kW of electricity, enough for about 14 average European homes. A head of as little as 0.7 meters (2.25 feet) is possible for a vortex generator. The much lower rise makes it easier to locate a vortex generator on a smaller waterway, without the need for high dams and other interventions typically associated with hydropower.
The vortex system is about 80% efficient, comparable to a standard turbine. However, the vortex cannot scale as large as a turbine power plant. A vortex has a range of performance up to about 150 kW, while a traditional turbine can reach up to 100 MW.
A system that both generates electricity and helps to clean and purify the water is a great technology of the kind we like to see.
Thanks for the tip, VikingHouse
For much more technical detail see;