An alternative method of measuring head is to use a length of hose and a pressure gauge. Insert the hose into the stream and measure the resulting water pressure at the lower end with the gauge. Repeat this procedure, continuing downhill until you reach your proposed turbine location. Add up the accumulated pressure readings to obtain your head.
Another vital factor in estimating power is the friction or head loss in getting water from source to the turbine. If the source is far up a hill or mountain, you will probably build the inlet pipe (penstock) of plastic or aluminium pipe which are both light and easily assembled. If you are planning a low-level installation at the foot of a dam, you will still need some pipe, since it is common practice to locate the turbine as far down the slope as possible to gain head. In either case, determine head loss from the appropriate pipe manufacturers flow resistance chart, or contact Tamar Designs for assistance, and trim your potential power source back accordingly.
[ Introduction ] [ Gross Head Sketch ] [ Measuring Flow Rate ] [ Water Flow Tables ]
