By Julie Karel - I’m a 4th year PhD student in Materials Science and Engineering at University of California – Berkeley, and I have been a blueEnergy volunteer in San Francisco for almost 2 years, helping with research projects and event coordination. Recently Mathias asked me to help teach various groups in the Bay Area how to build and assemble wind turbines. I immediately said “Yes, that sounds great!” The only catch is that I’ve never built a wind turbine before. As it turns out, there aren’t many opportunities to work with wood, copper, fiberglass resin and steel when you live in an apartment in San Francisco. No problem though, there would be training sessions to get us geared up. So, we gathered at Mathias’ house in Berkeley on a Saturday afternoon in early March for some turbine building lessons. In attendance were Christian Casillas, Lizzie Reisman, Phil Homer, Andreas Karelas and myself (i.e volunteers, staff and alumni). First, Christian Casillas and Mathias reviewed the physics and mechanics of blades in horizontal axis wind turbines – arguably one of the most important parts of the system. We learned all about angle of attack, blade twist, lift, tip speed… and much more. We had the opportunity to ask a lot of questions, and Mathias and Christian had the chance to perfect their pedagogical skills.
Christian teaching blade dynamics
After a nice lunch, we got down to business - blade carving. I can’t say that I’ve ever built or carved anything – functional or otherwise – with wood, so suffice it to say I had a lot to learn. First, I had to learn the exact functionality of all the tools. Luckily, everyone was really helpful in explaining what we needed to do. We spent the next couple hours measuring, cutting (I got to use a Skilsaw!) and carving our blades. We didn’t quite finish before dark, but I got the general idea. I really loved working with my hands, learned a lot and definitely have a newfound appreciation for the craft of woodworking.
Later that week, a skeleton crew (Christian, Lizzie and I) went back to Mathias’ house to discuss coil winding and soldering. I work in a condensed matter physics lab on thin film magnetism, so this topic I know a little about. We spent a lot of time talking about permanent magnets, electromagnetism, current, voltage, AC, DC, batteries, etc. It was interesting for me because I had never really thought about how the wind turbine actually produces electricity. Again, we didn’t get as far into the coil winding and soldering as we wanted, but I learned a lot and had a lot of fun! I feel like I will be ready to teach at the workshops thanks to a lot of help and patience from Mathias and Christian!