The Physics of Windmill Design

This video was created in partnership with Bill Gates, inspired by his new book “How to Avoid a Climate Disaster.” Find out more here: https://gatesnot.es/3u7UUVU This video is about how physics dictates the design of modern windmills - why they are so big, have so few blades, and have such skinny blades. REFERENCES H. Glauert: Aerodynamic Theory, 1935 Division L (Airplane Propellers), Chapter XI: Windmills and Fans Wind power extraction fundamentals https://home.uni-leipzig.de/energy/energy-fundamentals/15.htm Betz's Law https://en.wikipedia.org/wiki/Betz%27s_law Tip Speed Ratio https://en.wikipedia.org/wiki/Tip-speed_ratio Aerodynamics of Wind Turbines Book https://www.amazon.com/Aerodynamics-Wind-Turbines-Physical-Analysis/dp/1119405610 Penn State Wind Turbine Aerodynamics Lesson https://www.e-education.psu.edu/aersp583/node/469 Wind Power Physics youtube video https://www.youtube.com/watch?v=qx_M0nvDIGU Why do Wind Turbines Have Three Blades? https://rosemary-barnes.medium.com/why-do-wind-turbines-usually-have-3-blades-f7f95d714869 Wind Power Fundamentals http://web.mit.edu/windenergy/windweek/Presentations/Wind%20Energy%20101.pdf Wind Power Explained https://www.calcunation.com/blogs.php/the-physics-behind-wind-turbines/ Drag Coefficient http://dx.doi.org/10.1615/AtoZ.d.drag_coefficient Reynolds Number and Drag http://www2.eng.cam.ac.uk/~mpj1001/learnfluidmechanics.org/LFM_blank_notes/handout_8_v3.pdf Reynolds Number https://en.wikipedia.org/wiki/Reynolds_number Viscosity of Air https://en.wikipedia.org/wiki/Viscosity#Air Support MinutePhysics on Patreon! http://www.patreon.com/minutephysics Link to Patreon Supporters: http://www.minutephysics.com/supporters/ MinutePhysics is on twitter - @minutephysics And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Created by Henry Reich