Wind turbines keep getting bigger and bigger. The reason is that the power a wind turbine can theoretically generate is proportional to the disk-shaped area swept out by its blades. So, the bigger the blades, the more power can be produced by a single turbine.
That being said, real-world turbines don’t achieve their theoretical power output because they have limitations on efficiency. Things like rotor blade friction and drag, gearbox losses, and generator losses limit the actual power output of a turbine.
Despite all of these things, the latest and greatest wind turbines are absolutely enormous and produce almost unbelievable amounts of power. Chinese manufacturer MingYang Smart Energy has recently unveiled an 866-foot tall, 16-megawatt capacity offshore wind turbine. This narrowly exceeds both the Vestas V236 Turbine announced earlier this year and GE’s Haliade-X Turbine, rated at 15 megawatts and 14 megawatts respectively.
The rotor diameter of the giant Chinese turbine is nearly 800 feet, set by its 387-foot blades that sweep out an area of nearly 50,000 square feet. A single one of these turbines can generate 80,000 MWh of electricity in a year, enough to power more than 20,000 households. (It boggles the mind to consider that just one rotation of the blades of such a turbine can power a couple of homes for an entire day).
Offshore wind farms choose the largest wind turbines in part because of the high cost of installing turbines and transporting the electricity. It is preferable to build fewer turbines because fewer towers, cables, and ground anchoring systems need to be constructed, making the project less complicated.
Photo, posted November 19, 2015, courtesy of Scott Flaherty / USFWS via Flickr.