Together with Jon Sumanik-Leary (E-Futures PhD Student at University of Sheffield) we’ve been measuring the power/windspeed performance of some of the turbines on Scoraig. The results aren’t always what I expect but they are interesting. There’s an article about it on the Logic Energy website. And here is a link to a paper that Jon published about the first complete study.
Here is the power curve we measured for a 1.8 metre diameter turbine
Thanks for sharing this data Hugh, it’s very interesting and great to see a proper study. I was interested to see the study reference to the airfoil being “based” on the Aquila airfoil. This and other flat-bottomed airfoils like the Spica aren’t great at low reynolds numbers, maybe this contributes to the overall output power being lower than that expected from the design.
I’m in agreement with Chris Olsen that we need to concentrate on all the tiny percentages that add up over time. Better airfoils, tails that get the blades back into the wind quickly during gusts etc etc…
The study is good and the turbine produced power for the whole duration which is more than can be said for some commercial turbines in other studies!
hi Jan,
We can no doubt move forward with the design and make improvements, especially with the resources brought by cooperation through Windempowerment, and all of the people who are involved worldwide. Personally I am not so interested in tiny percentage improvements in efficiency to be honest (especially if they make the aerodynamics more complex to produce) compared with simplicity and reliability. The reason I choose to teach people this airfoil ‘section’ is that it’s practical to reproduce and it works, but I am not closed to other ideas.
The tail furling system also has it’s shortcomings (especially on turbulent sites) but once again it’s simplicity I aim for, and improvements are always possible without sacrificing that principle.
Chris is full of great ideas and that’s why I follow his work and pass it on here, but he is much more of an engineer (glorifying precision) and not so much interested in doing things simply using basic tools and basic skills. My work is around making wind turbine design accessible, to all whist keeping a good standard of efficiency (especially in low winds), and above all reliability.
Hugh