Environment

Folding, modular rotor blades designed for giant wind turbines

Folding, modular rotor blades ...
The huge wind turbines are designed to fold up to avoid taking damage in high winds
The huge wind turbines are designed to fold up to avoid taking damage in high winds
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The huge wind turbines are designed to fold up to avoid taking damage in high winds
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The huge wind turbines are designed to fold up to avoid taking damage in high winds
Design team member Todd Griffiths with a model of a 50 m blade segment, which forms part of Sandia's roadmap to the new exascale design
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Design team member Todd Griffiths with a model of a 50 m blade segment, which forms part of Sandia's roadmap to the new exascale design

Sandia National Laboratories hasrevealed its plans for the extreme-scale Segmented UltralightMorphing Rotor (SUMR). The turbines are built to deal with the extreme conditions of an offshore farm, featuring a folding build to cope with high winds.

The majority of current US windturbines produce between 1 and 2 MW of power, using blades around 165ft (50 m) long, and even the largest commercially-available modelsare only capable of 8 MW output, with rotors measuring 262 ft (80 m).Sandia plans to make its new blades much larger, two and half timesthat of any rival, producing awhopping 50 MW of power.

Of course, when you're building thatbig, there are some significant challenges to overcome. Manufacturingand transporting large scale rotor blades is expensive andlogistically difficult. To combat that, the new blades can bemanufactured in segments, lowering costs and making them much easierto transport.

The new design also places the turbinesdownwind of the tower, rather than in the upwind position ofconventional designs. When dangerously high winds strike, the bladesare able to fold in to avoid damage, opening back out to takemaximize energy production once the weather calms down.

Design team member Todd Griffiths with a model of a 50 m blade segment, which forms part of Sandia's roadmap to the new exascale design
Design team member Todd Griffiths with a model of a 50 m blade segment, which forms part of Sandia's roadmap to the new exascale design

The design is also inspired by the waythat palm trees move in storms. The trunk features a segmented buildwith a series of cylindrical shells, which able to bend in the windwithout compromising segment stiffness.

Exascale turbines such as this couldhave a huge impact on green energy production. The research wasfunded by the Department of Energy's (DOE) Advanced Research ProjectsAgency Energy program, and could provide a good way to reach its planto provide 20 percent of the country's energy from wind by 2030.

"The US has great offshore wind energy potential, but offshore installations are expensive, so largerturbines are needed to capture that energy at an affordable cost,"said the lead blade designer on the project, Todd Griffith.

Source: Sandia National Laboratories

6 comments
ivan4
There are several very large problems with this with the largest being maintenance costs. Anything operating in a marine environment requires more frequent maintenance and suffers high corrosion rates plus problems with salt build up in joints, exposed gears etc. Working to fix any problems requires specialist ships, just as do the off shore oil platforms, but without the financial backing that the oil companies have. The next problem is the induced fatigue caused each time that a blade moves into the tower shadow. The loss of lift in that instance can, and most probably will, cause blade whip and if it is great could cause the blades to strike the tower. Even if the blades don't end up striking the tower their life will be rather short especially if salt gets into the folding joints and causes uneven folding. That could end up with the blades tearing the unit apart. Not a very good outcome.
Matt Tritt
There is nothing "new" about doownwind wind turbines OR down-wind coning rotor blades. The Scottish company Proven developed this approach years ago for small scale wind, with the largest rated @ 15 kW. I was an importer/wholesaler for Proven in the mid-2000's and had plenty of opportunity to witness both the up and down-sides to the concept, but corrosion from salt air wasn't one of them. Proven used a flexible hinge plate backed with heavy springs to facilitate coning, which works well in smaller applications - but I am quite sure that taking this approach in a very large scale machine will be something of a nightmare when it comes to gryroscopic dynamics, in conjunction with all the other unexpected consequences associated with very large flexible, rotating machinery. I would personally not want to be within a long mile of the test site while they work out the tons of bugs that will surely accompany it's development.
Island Architect
Oh great! One more low efficiency wind turbine. Gotta hand it to the power of the lemming instinct! Bill Allison hit the Betz limit at 59% efficiency 35 years ago with his design and this generation of idiots is irrevocably hooked on low efficiency mystically thinking that the thing to do is fly rather than resist. And Bill absolutely refused to use a confined flow wind tunnel because he knew that the performance results would actually be supercharged. Other generations weren't all that stupid it seems. But we have one now that doesn't care about efficiency, and never posts it. Back to Motorcycles! Bill
Douglas Bennett Rogers
The resin components aren't affected by salt spray. Sand and sun in the dessert are much worse. Not having to deliver components over the road saves a lot of money. Out of the way of most birds. Dense composites fail by single cycle overload, rather than cumulative cycle.
Just Cause
Why are we trying to avoid high winds, we should be solving the real issue that the turbines fail in high winds. We need a wind turbine that can survive high winds (and capture all that energy).
Timelord
@Island Architect This isn't a generation that doesn't care about efficiency. It's a generation that isn't as gullible as you are with your wild claims.