Water Wheel Pitchback

The pitchback water wheel uses the potential energy of the water to help rotate the wheel, but it also uses the kinetic energy of the flowing water below it to give an extra push. This type of waterwheel design uses a low head infeed system which provides the water near to the top of the wheel from a pentrough above. Pitchback water wheels are suitable where there is a small stream with a height difference of more than two meters. The pitchback wheel uses the technique which is also suitable for streams that experience extreme seasonal variations in flow. The most important advantage of this wheel is that the efficiency is greatly increased to over 80 % of the water's energy. It is caused by drive from the weight of the incoming water and by the pressure of water directed into the buckets from above, as well as the flow of the waste water below. It means that the pitchback waterwheel uses the energy of the water twice. The weight of the water in the buckets causes the wheel to rotate but in the opposite direction to the direction of the water flowing above the wheel. As the angle of rotation nears the bottom of the wheel, the water inside the bucket empties out below and then buckets continue around the rotating wheel as before.