Hydrokinetics in South Africa


Renewable energy advocates, governments and investors are increasingly becoming aware of river currents and the huge associated energy potential. Because hydrokinetic power generation relies simply on the extraction of energy from the natural velocity of water, these power systems can be placed into sources of flowing water with minimal infrastructure or environmental impacts.
Hydrokinetic energy is not a new application of the concept of using the energy from moving water to create electricity – “dam-less” as opposed to conventional dam wall hydro power or other man-made barricading structures behind which potential energy in the water is stored – water wheels of various types have been used in numerous applications for centuries.
The ideal location for a hydrokinetic turbine is to be located in deep strong flowing rivers or immediately downstream from an existing conventional hydropower plant where electric transmission wires and interconnection facilities are located, and where the energy remaining in the water current exiting from the turbines in the dam can be reused. Small Power Barges in a range of 5 to 30 KW could easily be floated in channeled and engineered waterways such as irrigation canals.
How the Hydrokinetic Power Pontoon Works
Our hydrokinetic technology is designed for use in river and ocean currents with a horizontal axis turbine. Almost like mounting several Pelton wheels on the same shaft but better, as the advantages of a vertically submerged blade has similar performance characteristics to a
horizontally mounted Cross flow turbine. The core of our patented technology is in the design of the turbine blades. The leading edge offers reduced resistance, while the trailing edge is aerodynamically optimised to reduce the Flat Dynamic Effect. The turbine is horizontally mounted on a catamaran type hull or barge and partially submerged into the water flowing beneath the barge.
In an open-river setting, hydrokinetic power projects will have a capacity factor (CF) of better than 98% because power will be generated by using a constant water current to the effect that it would be considered a “base load” plant.
The rotational speed of the turbine is very low, and can be stopped from spinning in a matter of seconds through automated fault sensing equipment and the turbine can be lifted out of the water and placed in service mode in under 2 minutes.
The barge on which the turbines are mounted (and the turbines themselves) is able to cope with fluctuations in water levels, substantial velocity increases, and direct impacts from large and fast-moving debris, (the turbine is self-cleaning for small debris and floating plant material) and the only flow parameter that would decrease power output would be a decrease in the flow rate of the water underneath the barge. During extraordinary adverse conditions or flood events, the barge could be removed from the river if necessary.
Since the power is proportional to the cube of velocity and density of the water, a slower flow rate of (say) 1 meter per second will yield less energy than a flow rate of (say) 3 meters per second, and depending on location and other factors such as depth, our turbine blade size would be engineered for optimal performance given specific site conditions. For instance, the turbine blade could be long and broad for slow moving deep currents, or shorter and thinner for fast moving shallow currents.
The power barge is designed to last for at least 20 years lifespan, and because of very few moving parts, will have very low maintenance costs and downtime. 
Not all rivers have suitable annual flow rates due to seasonal rainfall variations, or flow deep enough to sustain the floatation requirements due to the weight of the barge. In many parts of the world river beds are exposed during dry seasons, and would be much less practical for the installation of a power barge. The barge will theoretically operate much more efficiently in the middle of a straight section of a river, or closer to a bank in a winding river where the water flow speed is higher, and in either case, the location needs to allow river traffic to pass unimpeded and at a safe distance.
Tying into the electric power grid should ideally be at a location close to distribution lines, or alternatively, close to an agriculture, industrial or commercial end user in order to avoid the major expense of lengthy overhead power lines.
Our patented design of the Vurbine® blade is much more efficient than conventional water wheel or other turbine types, (See here) reduces aerodynamic resistance against the leading edge, and also reduces the Flat Dynamic Effect of the trailing edge. The design combines impulse and reaction types for optimal mechanical efficiency.The turbine blades and turbines are easy to repair, modify or upgrade. If we improve our blade design or use other materials such as graphite, composites, metal alloys or industrial grade high strength plastics or make technical advances that achieve a higher power output, for example, we can  lift the turbine from the water and modify the existing turbine in about a day.
Licensing and Permitting
Many countries and governments around the world are pro-actively encouraging renewable energy and environmentally friendly projects, and are streamlining permitting and creating fast track incentives for such developments.
Aquatic Life and Environment: Low Impact Technology.
Some wildlife advocates may be concerned that hydrokinetic turbines may harm fish and other types of wildlife. This is generally a valid concern where traditional hydro turbines work at several hundred rpm which could cut and kill fish. Our turbine spins, or the blades move, at the same speed or less than the water flow rate, and in the same direction of the water flow. We compared our turbine with published reports by the U.S. Army Corps of Engineers’ for fish mortality equations in order to look at potential mortality to fish and predict less than 1% mortality.
We believe that there will be no material adverse impact to marine life, and, and we expect zero impact on water quality as pertains to temperature, dissolved oxygen, or turbidity.
The technology’s Low Impact characteristics compares favorably with “Run of River” types of installation which requires substantial earthworks, concrete pouring and related infrastructure, and which almost invariable hinders the passage of fish and other aquatic life and organisms.
Bold Moves
We believe that our technology makes it unnecessary to build dams with the associatedenvironmental and socio economic impacts. Vessels and barges of the catamaran hull type today exceed 3,500 tons load capacities, meaning that our turbine could be engineered and built to exceed a hundred tons, delivering hundreds of Mega Watts per turbine. It can be deployed on rivers like the Rhine, Mississippi, Congo, Nile, and Amazon to name a few, where several Power Barges could be strung out, or in ocean currents.