5 ms·
I looked into this in depth once. Basically if you look at the very early wind turbines in northern california, which the number comes from originally, these t
by hadlock 7y ago
I looked into this in depth once.
Basically if you look at the very early wind turbines in northern california, which the number comes from originally, these turbines had blades about 20 feet long, and spun very, very fast to produce any kind of power. Almost like a slow blender. Blades would rotate once per second of faster. They were very obviously dangerous even to the casual observer.
This was 20+ years ago during the infancy of the industry.
This is in contrast to all modern turbines, those built after ~2005, which is to say, well over 99%, it can take over 15 seconds for a blade to sweep through one revolution. Getting hit by one of these blades is unfortunate, but causes significantly less damage.
Comparing a Gen 1 "blender turbine" and a Gen 2 modern "sweeper turbine" is almost criminal when doing bird impact studies.
Finally the state of california quietly disabled the blender turbines as they were both very expensive to maintain being first gen technology and more importantly they were generating the bulk of bird strike fatalities and grossly inflating the number of bird fatality numbers for the global industry. The replacement of these ~20 blender turbines was 3 sweeper turbines and you'll note since the decommissioning of the last of the blender turbines, bird strikes for turbines fell off a cliff.
- todd8 7y ago> This is in contrast to all modern turbines, those built after ~2005, which is to say, well over 99%, it can take over 15 seconds for a blade to sweep through one revolution. Getting hit by one of these blades is unfortunate, but causes significantly less damage. If the blades turn slowly, too much wind passes through the gaps between the blades without interacting with the turbine. Although modern turbines may appear to be turning leisurely, because of their scale the blades are traveling large distances on each revolution resulting in high impact speed. The latest land based turbines being made by GE have a rotor circumference of 0.3 miles[1]. Modern turbine blades reach speeds of 180 miles per hour at their tips.[2,3] The blades of new turbines travel so fast that erosion of the blades is a serious problem. [1] https://www.ge.com/renewableenergy/wind-energy/onshore-wind/turbines/cypress-platform https://www.ge.com/renewableenergy/wind-energy/onshore-wind/... [2] http://www.acua.com/uploadedFiles/Site/About_Us/WindFarm.pdf http://www.acua.com/uploadedFiles/Site/About_Us/WindFarm.pdf [3] https://gizmodo.com/the-worlds-biggest-wind-turbine-blades-are-so-long-thei-5930272 https://gizmodo.com/the-worlds-biggest-wind-turbine-blades-a...