Asian Resources Int'l Limited MHG-T2 manual PowerPal T2 Turgo

AB

The penstock is shown by the black line A-B. In the first diagram (A) the penstock follows the stream. This may lead to unnecessary length and cost. In diagram B, the most direct route is selected to reduce length and cost. Diagram C shows the best alternative where a side channel or ‘power conduit’ is cut into the side of the hill. This carries the water to a point as close to above the turbine as possible and best reduces the length of penstock required.

The power conduit roughly follows the hill’s contour and need only be a simple ditch say 30cm x 30cm in section.

CWhen installing the penstock, try to keep it as straight as possible and avoid sharp turns or angles. To do this, part of the hillslope may need excavating while in other places the penstock may need supporting with poles etc. Steeper terrain has advan- tages over more gentle terrain as cost is reduced by the use of a shorter penstock.

The forebay, or water holding tank at the top of the penstock is designed to contain a water volume of at least 2.5x the volume of water in the penstock i.e. 440 litres. Dimensions of the ideal design are shown in the system diagram although the main point is to ensure that the forebay won’t become empty.

The top of the penstock is typically placed not at the bottom but some way up the forebay wall so that the bottom of the forebay acts as a sink for rotting leaf litter, deposited sand and mud etc. This sink may need periodic cleaning out. Another good idea is to cover the end of the penstock with a piece of wire mesh (debris screen) to keep leaves etc. from flowing in and clogging the turbine. See Appendix A for the ideal forebay design.

PowerPal™ T2 Turgo 7