New wind turbine designs are far more reliable, produce maximum power in all wind conditions

[txlibdem]

A Canadian company has come up with a novel design for large wind turbines.

The three bladed rotor attached to the main shaft is attached to a flywheel driving the friction wheels which operate multiple generators. The rotor and flywheel operate with the same inertia. The design is reliable because it inherently limits the torque transmitted through the drive and incorporates the following key advantages:

- No gearbox – no oil, gearbox bearings or gears to fail
- No single point of failure
- Reduced costs overall for manufacture, operations and maintenance
- Not reliant on conventional turbine supply chain for bearings, gears, generators or gearboxes
- Friction drive system built to absorb sudden wind gusts – energy is stored as momentum and recovered when gust passes
- It is impossible to overload drive train
- Multiple Generator Drive, each operate at the most efficient point – each generator only operates when there is sufficient wind, ...therefore energy yield is higher even when running below rated power
- Independent load paths giving continuous operation at part load while waiting for maintenance or replacement of component parts
- Distributed load paths allow operation up to 95% availability during faults as only the fault load path is isolated
- Distributed power system , low torques
- Ability to maintain, service and replace all drive system component parts using only the internal nacelle crane
- Full power conversion – grid friendly and variable speed
- Scalable to 7.5 MW

http://www.cwind.ca/html/fd.html
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The blades on most turbines use the wind to turn a drive shaft connected to a gearbox. The gearbox manages the rotation of a second shaft that connects to a large electrical generator. The gearbox is the heaviest piece of equipment in a wind turbine's "nacelle" (the section at the top of the turbine tower). It's also a piece that's among the most vulnerable to failure. Sudden wind gusts put the gearbox under tremendous mechanical stress. Over time this can wear down or break the teeth off its metal gears.

CWind's design does away with the gearbox completely. Instead, the drive shaft is connected directly to a large metal flywheel. Hugging the outside of the flywheel are eight smaller secondary shafts, each connected to a 250-kilowatt generator and each lined with several specially designed tires that grip the surface of the flywheel. As the flywheel spins, it engages the generators by turning these tire-lined shafts. "We're using friction. It's not mechanically hard-coupled," says Na'al Nayef, a CWind engineer and co-inventor of the system.

http://www.technologyreview.com/energy/24050/?mod=related

According to their website, CWind wants to manufacture their wind turbines in Ohio. I hope they do.

Siemens has been testing gearless wind turbines since 2003 and has announced their SWT2.3-113 wind turbine which boasts a 50% reduction in moving parts compared with "standard" wind turbines and uses an innovative design that wrings the most power out of low and medium wind speeds.

Direct Drive Generator
+Permanent magnet design
+Totally enclosed, easy to handle lightweight design
+Optimum reliability and efficiency

http://www.energy.siemens.com/hq/en/power-generation/renewables/wind-power/?nocache=1302282142267%20%20%20%20%20#webfeature=/apps/features/swt-2-3-113/all/en

GE says they will have a gearless wind turbine on the market by the end of 2012

The multiple wheels and bearings in a wind turbine gearbox suffer tremendous stress because of wind turbulence, and a small defect in any one component can bring the turbine to a halt. This makes the gearbox the most high-maintenance part of a turbine. Gearboxes in offshore turbines, which face higher wind speeds, are even more vulnerable than those in onshore turbines. Butterfield is leading a gearbox-reliability study with turbine makers to identify design weaknesses that could be avoided.

ScanWind's turbine design gets rid of the gearbox completely. Instead, the rotor shaft is attached directly to the generator, which spins at the same speed as the blades.

In a turbine generator, magnets spin around a coil to produce current--the faster the magnets spin, the more current is induced in the coil. To make up for a direct drive generator's slower spinning rate, the radius of rotation is increased, effectively increasing the speed with which the magnets move around the coil.

...snip...

GE, meanwhile, expects to have a market-ready product by late 2012. It is targeting the European market initially because nearly all of the 1,473 megawatts of offshore wind power currently available come from installations along European coasts. According to industry analysts, this capacity must reach 30,000 megawatts by 2020 if the European Union is to meet its renewable-energy targets.

http://www.technologyreview.com/energy/23517/?mod=related

Elsewhere in the article it says that GE bought ScanWind.

These new wind turbines do away with the gearbox and the oil that it needs, which reduces maintenance costs as well as increases reliability. This makes them perfect for offshore wind farms. Gearless wind turbines should be the de facto standard in decades to come due to reduced maintenance and repair costs alone.

[FSogol]

1. Produce maximum power in all wind conditions? Impossible. n/t

[txlibdem]

2. Maximum is a qualitative term, not an absolute number

Why impossible? Nowhere did I say that it produces the same output regardless of wind speed. I think you misunderstood my meaning, perhaps?

[AtheistCrusader]

4. Author probably meant 'high' wind conditions.

Because NO wind, is a 'wind condition'.

[txlibdem]

6. Mea Culpa

:hi:

[AtheistCrusader]

8. I didn't even realize I was talking to the OP.

I need a nap.

[madokie]

3. I like the idea

K&R

[txlibdem]

9. I expect the gearless wind turbines to dominate the offshore wind market

eventually. Today's wind turbines, those with a gearbox, require oil replacement at regular intervals (just as an automobile does). Imagine a few hundred offshore wind turbines off each coast. How much would be spent just on sending maintenance crews out to change the friggin' oil! I think they're onto something.

[kristopher]

10. Just for reference though, their service interval would equal 200,000 miles for a car.

Their required service intervals approximate running your car 200,000 miles between oil changes.

[txlibdem]

11. You drive a LOT then. That would be about 20 years for most folks

Which is, as usual, not accurate.

--------------------------
"Most gearbox manufacturers recommend no more than 36 months between oil changes."
... from: http://www.rgbgreen.org/aggregator/sources/3?page=7

Then they go on to state that a better filter can extend the life of the oil to 60 months (5 years). BUT:
"kidney-loop filtration provides an oil flow to clean the gear oil independent of the main flow filter. Oil-aging products and particles larger than 3µ are removed from the lubricant. The filter also removes moisture from the oil. Contrary to common thinking, finer filtration does not remove additives. They remain in the gear oil. The upgrade consists of a compact pump and filter unit, installed near the gear coupling or on the gearbox. The unit siphons oil from the lowest point of the gearbox through a hose, cleans oil inside the unit, and returns it to the gearbox.

Change the first filter element at 6 months and then every 12 months. Oil changes then can lengthen to intervals up to 60 months."
... from same link as above.
----------------------------

So you either change the oil every 36 months or change the filter every 12 months (and then change the oil every 60 months).

None of which works out to 200,000 miles for anyone even remotely similar to the average driver. Taxis, yes. Long haul truckers, perhaps. Cops, maybe. But "your car?" Uhhhhh, no.

The point still stands. With hundreds of offshore wind turbines on the Pacific coast and hundreds more along the Atlantic coast that is a whole lot of specialized maintenance time and expense that the gearless wind turbines save you. And gearbox failure (and the downtime and maintenance expense) is avoided altogether. No gears = win, win for the wind farm developer.

[kristopher]

12. WTF are you talking about?

There is X amount of usage (equaling wear and tear) between scheduled servicing for automobiles.

When you look at the amount of usage between turbine servicing intervals, it equates to operating an automobile 200,000 miles.

The difference is that there are no carbon deposits accumulating in the turbine lubricants, and the range of operating temperatures is far less extreme than with an automobile.

Yes, as a percentage of its cost, wind spends more on operations and maintenance than centralized generation. However that is more than offset by the lack of fuel costs. Apportioning costs in this manner is also far better for the local economy hosting wind, since it means the money people pay for energy goes to provide jobs to the area instead of enriching the minerals mining and petroleum industries.

[txlibdem]

13. Ya lost me with that one

What makes you think that maintenance crews will be sourced from local populations? Where is that written? Especially with a multi-million dollar piece of specialized hardware like a wind turbine. My guess is that each company would have their own maintenance crews and send them running around to all of their wind turbines on a schedule.

To your last paragraph: that is exactly why gearless wind turbines will dominate the market. It may take some time, a decade perhaps, but IMO it is inevitable. Removing the maintenance and repair costs will make a gearless wind turbine more profitable than one with a gearbox. Simple economics will dictate the winner.

[kristopher]

14. I think it because that is what happens

Just like the operators of power plants are local residents.

[madokie]

15. I'm sorta surprised that they have to have a gear oil change

The differential oil in automobiles never need changed or none that I know of do unless of course you immerse them in water for a while. there is no contaminants that can get in as in a cars engine. The manual for my ford truck says that the transmission never needs any oil changes either.
I'm not sure that the information is correct that the wind turbine gear boxes need an oil change other than if they have a gear failure where there would be pieces of gears in there. Under normal operation there is no wear, ie no shaving, in a normal gear box except if there is a gear failure.

Are we sure that maybe that information about the oil needing changed is only pushed by an anti wind turbine goon.

The reason you have to change oil in an automobile engine is because of the gas/diesel, whichever the case that gets past the rings and the fact that they are running at such high temperatures and the additives they add to the oil for those reasons wear out but that wouldn't be seen in a gearbox in a wind turbine.

educate me if you would.

[AtheistCrusader]

5. Pretty cool. Gearboxes suck.

As do overspeed disconnects.

[txlibdem]

7. The KISS principle is almost always the best way

I like the GE gearless wind turbine that has 50% fewer moving parts. How can you not gain market share with that?

[wtmusic]

16. Wonder what the efficiency losses are with a friction drive

compared to gears?

Also curious if putting that much weight high in the air doesn't make anchoring it substantially more complicated and costly :shrug:

[madokie]

17. From the link what I came away with was that there would be less weight not more

A gear box going from 200 or so rpms to 1800 rpms for a four pole or 3600 rpms for a two pole or hell even 900 if they use an eight pole generator would be heavy. my bet is it would be less weight. Traction drive as they are proposing is not friction drive, differences in the two. In a true traction drive there would be very little losses on the par with gears.