Cool 3D printed alternative energy builds

I really like the stirling engine build.  The projects are nice but…not so sure how long they would last (plastic) and being outdoors.  But they would be good learning projects.

http://www.3ders.org/articles/20150406-harvest-your-own-energy-using-3d-printed-wind-turbines-and-solar-stirling-engines.html

http://www.reprap-windturbine.com/index.php?id=18&L=1

Note you have to “buy” the plans to get them to print them out on your 3D printer.