As my summer immersion in India comes to a close, I thought I’d share a little more about the mission of Minvayu and what we’ve hoped to accomplish over the past couple of months. The primary goal of Minvayu is rural electrification. That is to say, many villages in the rural (but not necessarily remote) areas of India have little to no access to an electric grid. Extending the central electric grid to the network of villages around India would be both a massive and expensive undertaking, so one of the solutions is to build an energy infrastructure comprised of distributed power generation using wind, solar, and hydro.
Minvayu serves this need by hosting workshops on easy to manufacture wind turbines based off of the Hugh Piggot design. The focus is on empowering villagers to construct and maintain their own turbines rather than selling a product and performing all of the maintenance ourselves. Additionally, the students and engineers at Minvayu assist in the research and development of new ideas to make small scale wind more accessible in terms of cost and manufacturing capabilities. The hope is that these ideas can then be shared with other designers to further empower villagers.
My work in particular revolves around new design concepts for the turbine blades. Rapid prototyping has become much more common due to the relatively low cost of 3-D printers, and we are also seeing the availability of CNC milling machines skyrocket. With this technology, we are able to introduce a new level of complexity to the blade design that was previously too difficult using hand tools alone. With more precise control over the geometry of the blade, I was able to design blades that maximize energy production over a range of wind speeds and stall (become less efficient) during potentially damaging high wind speeds. While this is nothing new for large scale wind, it has been very difficult until now to cost effectively manufacture the complex geometry of a blade for small scale wind. Maybe one day, people will be able to visit an online repository of blades designed for different conditions, select the design that is most suitable for their location, and have the blades manufactured in a day’s time at their local shop.
Another concept involves manufacturing the blades out of bamboo rather than red cedar. The hope here is that the bamboo blades will be flexible enough to furl (bend) during high wind speeds to minimize the risk of damage to the turbine generator. While we were able to complete basic material testing on bamboo over the course of the summer, additional testing is necessary to really understand to what extent the bamboo blade will bend under heavy loads and if the blade will fully regain its original curvature when the load is relieved. Blades that successfully furl and unfurl in varying winds would save us from having to design and install different control mechanisms for high speed winds, further improving the accessibility of the machine.
The next step is to prototype and refine the designs that I described above. If successful, we would begin to introduce them in our various training workshops, assuming that the technology is appropriate for the location that we’re targeting. For instance, remote villages will not have access to CNC machines, but it might be possible to sell kits that the villagers still assemble and maintain. I consider myself very fortunate to have had this experience, and I am hopeful that through the efforts of organizations like Minvayu, we can empower people without relying on traditional and harmful methods of energy generation.