Bigger, Better, Simpler & more Power. A new deep water contra rotating wind turbine. One to follow.

Capturing wind energy at sea is advancing at pace in both enhancing and optimising existing designs, particularly the ubiquitous 3 bladed wind turbines (Hornsea Wind Farm a typical single turbine is average 2.5 to 3 kwh max) but also providing us with some interesting new conceptual and prototype designs. Which ones will win through?

The fundamental challenges of this off shore green energy category are , 1) depth of water. Most offshore wind turbines are presently in 20 to 50 meters depth and are anchored to the sea floor. Deep water devices offer significant different challenges but there are a lot of population concentrations with only deep water coastal regions. 2) Distance of the farm from the shore and/or to the end user. More distance means more difficult maintenance challenges with boats doing 6 to 10 knots plus of coarse the more obvious energy losses due to a longer cable. 3) The three bladed turbines are essentially top heavy and are seemingly reaching their diameter limit at around 250 meters and with a power output of around 15 to 18 MW. (Article here) 4) They are mechanically complex. Most have two generators within them to be optimum at different wind / rotation speeds and use a heavy duty gearbox. This means they are relatively expensive and are difficult to maintain with most of the kit being high in the air.

World Wide Wind of Norway The new VAWT concept.

Two Cylindrical rotors contra rotating.

This new concept seems to address several of the above issues and their limitations. Its at the prototype stage with scale production forecast for 2029.

It offers approximately double the output of present wind turbine designs, is easier to maintain, is also suited to deeper water, takes a smaller footprint, (some think will become an issue in the future, particularly as nearshore real estate is becoming more expensive and is competing for wave energy capture.

The lower centre of gravity is significant in it enhances deep water stability and simplifies construction and maintenance.

The top rotor spins the generators stator in one direction while the bottom rotor spins the generators rotor. This increase in relative speeds gives its higher out put performance. 30mwh output predicted. It also works in any wind direction without any complicated mechanisms hence simplifying mechanical construction and cost.

The twin contra rotating turbine was used in the Pegasus jet engine which powered the Harrier jump jet. Without this it would simply have been an unmanageable gyroscope. (This machine I have more than a passing knowledge).

Article on Contra rotating deep water Turbine.

Video on Vibrating bladeless turbines (via facebook). An alternate new concept.

World Float Atlantic. Deep water wind turbine farm prototype.

World Wide Wind - twin contra rotating rotors. One to keep an eye on.