This is a technology for generating hydro power by extending an enclosed pipeline in to the head waters from a hydro power turbine. This hydro power development is based on the fact that the flow through a closed conduit (pipe) will be greater than the free flow through an open channel. Water flowing though a closed conduit is a laminar flow while water flow in a river is a turbulent flow.
Furthermore a pipe line extension will help to generate stream line. Usually water in a reservoir starts from zero velocity and enters into pen stock and it has to develop a stream line before it reaches the turbine. If the length of the pen stock is short the flow cannot develop sufficient stream line before it reaches the turbine. Then an extension of pipe line into head waters can be employed to develop the stream line. Reducing the diameter of the pipeline gradually towards the turbine can further improve the flow speed according to continuity equation.
Using these three factors the new technology can be employed to utilize hydro power from rivers having consistency of flow. This technology is inexpensive compared to hydro power projects built with massive hydraulic retaining structures. Sites for this purpose are available in many countries. Therefore this is an affordable and green alternative for small scale waterway sites as well as rivers having large flow without sufficient water head. An enclosed pen stock (pressure pipe line) is constructed up to the power house, form a suitable distance to generate hydraulic pressure.
Construction of pipe lines to a long distance is highly practical in our times. Thus flowing water of rivers also can be utilized to generate electricity where there is no facility for storing the water. Bringing a part of river flow through the pipeline laid along the river bed would not do any harm to biological inhabitant, chemical characteristics or physical layout of the environment.
Therefore a closed conduit laid on river bed from a higher location to lower location water will flow faster than the free flow of the open river. Also reducing the cross section of the pipe line towards generator house pressure accumulate at turbine location.
The bulb type reaction turbine of Kaplan type is most suitable for this purpose. The power generator is a Shaft-extension type tubular unit. It requires less space with smaller powerhouse and free discharge without flow interruption due to power house construction. Adjustable Wicket gates may be placed at intake point while runner blades may be made adjustable to provide the flexibility to adapt changing head and demand of different power output.
At intake point at trash track, flow control gate and fish screen are introduced. Most low head, low flow hydro power sources are not exploited since standard hydro power generation techniques cannot be employed in such conditions. The type of power plant intruded here is suitable for lowland rivers with sufficient flow.