A Case Study excerpted from Pere Ariza-Montobbio, Jesús López et al.:

“The Hugh Piggott (HP) small wind turbine has been used as the “reference design” of the open-source small wind turbine developed by the rural electrification research group of the NTUA, since the majority of existing locally-manufactured small wind turbines have been based on this design. To date, three small wind turbines have been manufactured in practical student workshops, two for battery charging and two for grid connection, with rotor diametres of 1.8m, 2.4m and 4.3m. The practical workshops are organised in the context of undergraduate dissertation projects and are open to all students of the NTUA. During these workshops, the small wind turbines are constructed from scratch by the participating students, a process that provides practical evidence of the ability of unqualified constructors to locally manufacture this small wind turbine technology. The educational aspect of these workshops is of significant value and provides a chance to experiment with a variety of learning processes.

The design manuals of Hugh Piggott have been a reference guide for locally manufactured small wind turbines worldwide and have proven to be valuable tools in spreading this knowledge, as they have been translated into more than ten languages. It has been estimated that more than 1,000 locally-manufactured small wind turbines are based on the Hugh Piggott design, many of which are in operation around the world. As rural electrification has been an obvious application of this technology, many NGOs and groups have used these design manuals to manufacture small wind turbines in developing countries,[10] while construction seminars for DIY (do-it-yourself) enthusiasts are organised by several groups around the world.[11] Since 2012, the Wind Empowerment association has tried to network most of the organisations involved with locally-manufactured small wind turbines around the world, with the aim of building the financial and human resources required for the activities of these organisations, and performing joint technical research while sharing technical information.

One of the main advantages of open source hardware designs, and of the “open design” philosophy in general, is the adaptability of the design. Open-source small wind turbine technology can be adapted to better suit different environments, such as coastal areas with high corrosion.
Another aspect of the adaptability of open hardware designs is the ability to use parts of the design in other open-source technologies and applications. This is the case of the open-source pico-hydro turbine developed in NTUA, which is a hybrid design between the locally-manufactured axial flux permanent magnet generator (Piggott, 2008) and the locally-manufactured small hydro casing and turgo runner designs of Joseph Hartvigsen. The specific design is a grid connected 350W hydroelectric which has been driven with a pump in the labs of NTUA (see Figure 5) with satisfactory results, while a battery charging prototype of the same design has been in operation for one year in a rural site in Greece.”