Abstract

The lack of access to electricity is still a huge issue in various regions around the world. Especially in rural areas many people are negatively affected. Renewable energy technologies like micro- or pico-hydroelectric turbines can offer a solution to this problem. Yet the distribution of these technologies is still developing slowly, also because the manufacturing process is very costly.

In recent times the concept of distributed manufacturing has become a more popular topic among futurologists, particularly because of the fast progress and dissemination of low cost open-source desktop manufacturing devices like 3D-printers. These Fused Deposition Modeling devices enable a strong reduction in cost and environmental impact through the alteration of the production process and yet there is still many fields of application where 3D printing has not yet been tested.

In this thesis the concept of distributed manufacturing with low cost open source 3D printers for rural electrification is analyzed and connections to the concept of commons-based peer production are demonstrated by a brief review of current literature. In order to demonstrate the applicability of 3D printing for low cost turbine manufacturing a case study is conducted in which runner cups of a pico-hydroelectric turbine are printed. As the process aims to be representative for a local manufacturing environment an open source 3D printer is assembled and an appropriate material, namely ABS, is chosen as a filament. An injection moulded nylon cup is scanned and a simplified finite element analysis is conducted confirming that the 3D-printed cup will withstand the mechanical stresses caused by the water jet. For the printing process different print orientations are tested and with a proper orientation 20 cups are printed, which are used for the assembly of the

runner. A cost comparison is conducted and tests are run at the test site to assess the performance of the different runners. The results of the tests show that with the printed runner losses of 4,2% occur for the overall efficiency of the turbine. The cost analysis indicates that the price for printing a cup is only 9,7% of the price for ordering the original cup.

In summary, open source 3D printing has demonstrated to be a valid manufacturing method for producing turbine runner cups in a distributed manufacturing environment and to be able to contribute to further reductions of the system costs of a hydro turbine.

Author: Arno Döpper

Responsible PhD: Kostas Latoufis / latoufis@power.ece.ntua.gr

Supervising Professor: Nikos Hatziargyriou / nh@power.ece.ntua.gr

PDF: Full version (English)