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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 hydropower or other manmade 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.
How the Hydrokinetic Power Barge 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 concave design of the turbine blades. The leading edge offers reduced resistance, while the trailing edge is aerodynamically optimized 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.
Our first barge is projected to generate 1 MW and produce 8,760 MWh electricity annually at a maximum rating through a synchronous AC induction generator.
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.
Project Location
Not all rivers have suitable annual flow rates due to seasonal rainfall variations, or flow deep enough to sustain the flotation 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.
Technical Innovations
Our patented concave design of the blade reduces aerodynamic resistance against the leading edge, and also reduces the Flat Dynamic Effect of the trailing edge. 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 proactively encouraging renewable energy and environmentally friendly projects, and are streamlining permitting and creating fast track incentives for such developments.
In South Africa, NERSA has recently published renewab