After finishing the tower and the HughPiggott 1.8 meter somewhere halfway the master class (as you can read in the last news contribution), all participants were confident that we also could succeed with the larger model. Last week we worked on two turbines with a rotor diameter of 3.0 meter; one producing 24V and one for 48V.
Thursday was the last day that we could assemble the whole system. Just before lunch some strange things happened with the electronics: a fuse was blown and we smelled burning electronics. Nevertheless we were very sure that the setup was correct and checked it already completely for more than three times. “OK”, I sayed, “just let me connect only the charge controller to the batteries, that works always.” So I first connect the minus of the batteries to the minus-connection of the charge controller. Thereafter I take the +48V of the batteries to connect to the plus-connection of the charge controller. You might guess what happened…. I still see the flash in my eyes 🙂 Apparantly the charge controller was already broken internally by earlier mistakes, giving a short-circuit between the battery input connectors.
Fortunately, Chaim has a lot of experience on electronics and repaired our charge controller the same afternoon. Only the power meter is probably unrepairable. In the end, when you realize that 18 participants are learning-by-doing during 15 working days, it is not too bad at all when only a power meter has been blown up at the end of the master class. Moreover, I find the aspect of safety much more important. No serious accidents happened during the training. So after the reparation we took the turbine down for a last final check and for painting.
Friday morning we hoisted the 3 meter 48V turbine. It performed very well when the wind arrived. Around lunchtime media and guests were arriving. The official closure was done by a guest of honour from the Rural Energy Agency (REA). After speeches from I Love Windpower, SEDC, the participants, Tatedo and REA, all participants received a certificate. Thereafter I decided to add a bit of Dutch tradition to this very Tanzanian official closure procedure. I explained, that in the Netherlands we will open a bottle of champagne when a ship is touching water for the first time. Therefore, we all moved from the conference room to the testfield with the wind turbine. Our guest of honour from REA released the break button and within a couple of seconds our turbine was picking up speed. I shaked the champagne, and just when the first Watts of power started to flow into the batteries, I plopped the bottle of champagne. I think the Tanzanians liked this Dutch tradition very much.
In conclusion, the master class on small scale wind turbines is a great success! Everybody is very welcome at the SEDC in Mbezi Juu to see how our own-built wind turbine is producing electricity in a quite efficient way.