Like mentioned earlier, the prototype of the 3 meter diameter HughPiggott turbine was finished some weeks ago. Unfortunately the wind at the location of the workshop is only high enough druing a couple of hours per day, and this even not on all days. During the assembly phase, we measured the correct voltage at a default speed, and hence concluded that the turbine was manufactured acurately. But we were left we the uncomfortable feeling of not having seen it in high wind yet.
That changed today when we installed the turbine in the back of a truck! We calculated the height of the pole so it would exactly accomodate the turbine without hitting the truck. That worked out nicely. Nevertheless the width of the rotor blades is wider than the width of the car. We picked the time during early afternoon which has the least cars on the road, but still busy. We took the road between Mbagala and Kigomboni, where not so many people are living. But still a lot of electric wires cross this road at a height of less than 4 meters. Everytime that we came across these wires, we reduced speed to pass them very smoothly.
With all these precautions we succeeded in doing a performance measurement from 0 up to like 40 km/h. Expecially for the Tanzanians who worked on the turbine, it was fantastic to see it spinnng over 200 rpm! It is quiet impressive if you don’t have seen this before. I was sitting on top of the batteries with a multimeter in my hand. Arthur was checking the road and possible high obstacles. Richard was driving the truck carefully. His son Patrick would climb to just below the turbine keep the blades as low as possible. The actual measurements we performed at a part of the road where no electric wires are crossing it. On this part, I saw that the current was nicely flowing into the batteries. We celebrated by eating a lot of fresh oranges.