Science

GE uses plastic surgery on wind turbine blades for more power

GE has found a way to extend wind turbine rotor blades without replacing them
GE has found a way to extend wind turbine rotor blades without replacing them
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GE has found a way to extend wind turbine rotor blades without replacing them
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GE has found a way to extend wind turbine rotor blades without replacing them
The extension process involves cutting the blade in half and inserting an new section
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The extension process involves cutting the blade in half and inserting an new section

Sometimes progress can be its own worst enemy, with early adopters being stuck with obsolete equipment that leaves them with the choice of living with out-dated technology or an expensive replacement. The green energy field isn’t immune to this, and as part of a US$2 million renewable energy project, GE has developed a way to make smaller, less efficient wind turbines into bigger more efficient ones with a bit of plastic (or carbon composite) surgery.

Windmills have been around for over 2,000 years, and have been used for everything from grinding corn to reclaiming much of The Netherlands from the sea. In these days when global warming is such a political hot potato, many governments have seen wind turbines as a clean, green alternative to conventional or nuclear power sources.

One problem is that wind turbines are not a very efficient power source, with many square miles of land containing thousands of turbine towers needed to replace a single coal-fired plant. Therefore, engineers are working to better understand how wind turbines work, and to come up with more efficient designs that put out a greater amount of power more predictably from each tower.

GE cites a paper in Environmental Science and Technology which states that the key to more efficient wind turbines is to make the towers higher and the rotors longer. This way, the amount of power put out by the wind turbine is increased without a proportional increase in the mass of the installation. The paper states that by following this rule, the average size of commercial wind turbines in the past 30 years has gone from 50 ft (15.2 m) to 500 ft (152 m).

However, that brings its own problems. For one, it’s all very well and good to come up with a better design, but wind turbines aren't cheap and any major improvement in design means that the wind farm operator is faced with a costly quandary: what to do with the old, inefficient turbines?

GE’s answer is to avoid replacing the turbines in favor of lengthening the rotor blades. That may sound simple, but given that the blades are made of composites and the shapes are as carefully engineered as the wing of a fighter plane, that extension has to be very carefully designed. Eventually, the GE team came up with a method to cut a 120-ft (27-m) blade in half, then insert a 23-ft (7-m) extension, which is blended into the original blade’s curve.

According to GE, the extension allows the turbines to gather power at lower wind speeds while boosting power output by 20 percent, and the modifications have exceeded the standards of the International Electrotechnical Commission (IEC) in both static tests and fatigue tests where the blade was put through 6 million cycles.

The video below shows a blade extension being installed.

Source: GE

18 comments
RelayerM31
These bird killers are wrong on so many levels. Give me static photovoltaic panels any day. Once these contraptions start breaking (remember if it moves it breaks) the intellectual back benchers will be reconsidering the "wisdom" of wind power.
Jabboson
Yeah that horrible clean energy must be banned!
Daishi
@RelayerM31 I googled your claim and found this: http://science.howstuffworks.com/environmental/green-science/wind-turbine-kill-birds.htm From that statistic wind turbines kill 1 bird for every 1,800 killed by cars and 1 bird for every 6,080 killed by power lines. If you look at the cost to produce electricity on a large scale onshore wind is one of the cheapest available methods. Depending on whose numbers you go by Solar PV is still about 50% more expensive. Source: http://en.wikipedia.org/wiki/Cost_of_electricity_by_source Based on Swanson's law if the cost of wind power remains fixed (it probably won't) the cost of Solar PV will catch it in about 6 years. Swansons law is "The price of solar photovoltaic modules tends to drop 20% for every doubling of cumulative shipped volume" which is currently about every 3 years.
Candy Hasbeen
Relayer, you realize that commercial wind turbines have been around for decades, right? How many have come crashing down on houses? Every single turbine erected in the US and Europe have to comply with building codes that define how close a turbine can be installed to a dwelling. It is called "setback". And as for your solar panels, do you know how toxic the process is to make those? The wind is much more constant in many more places than the sun. The sun sets every single day. The wind does not.
RelayerM31
Yes, I realize the turbines have been around for decades. As I drive past the wind farm near Bakersfield at the Tehachapi Pass I see (oh let's say) 1/4 of them inop on any given day. Fixing these Rube Goldberg contraptions is a nightmare. Do YOU want to pull maintenance on one of these babies? They're unsustainable, as are all large scale wind farms, due to maintenance issues. Once states have to start coughing up the money to service these money pits they'll cry uncle and stick with PV panels. Just don't use the PV panels that follow the sun. They're also a stupid waste of money. Use the ones that don't move. A good friend of mine is helping to develop the largest PV plant in the world in China. Non moving PV panels in an abandon strip mine is the order of the day over there. Good idea. The problem with these wind power panaceas is that hard working tax payers always foot the bill when it crashes and burns. The high minded libs who came up with the idea have already taken the money and ran. Smart will eventually win the debate but only after Stupid has run up an enormous bill.
Mel Tisdale
Better still as far as electrical energy concerned is the development of small modular nuclear reactors employing LFTR technology, or similar. All it is going to take is the realisation on the part of the public that all the easy oil has be extracted, leaving only the difficult (for 'difficult' read 'expensive') stuff. What about fracking? What about Monterey? is the appropriate response. Of course, we have to realise that electricity is not a straight replacement for oil when it comes to energy requirements. Elsewhere in this issue of Gizmag is an article about structural super-capacitors. I imagine the time will soon come when we will seriously consider a Manhattan type project to develop that technology and the LFTR installations to charge them up when installed in trucks and tractors. It is difficult to envisage how we are going to meet the food requirements of 9/10 billion people unless we do something along those lines. The biggest obstacle is the lack of scientific competence in the political community. (Look at the lack of action on climate change, if you can bear it, to see just how daft many of them are. I sometimes wonder if the captain of the Titanic refused to steer around the iceberg because it was not anthropogenic in origin. If so, no prizes for guessing his political allegiance.)
Slowburn
That is going to seriously unbalance the wind load on the bearings unless they make the towers taller too.
Grunt
I find myself in agreement with RelayerM31. The current iteration of wind turbines are relatively primitive and mechanically inefficient. I feel we are being rushed up a blind alley by well-meaning, but somewhat naive environmentalists. Of greater benefit, I suspect, will be the more subtle employment of ducted wind flow to generate power utilising venturi effects, such as was reported here on Gizmag a couple of weeks ago. Solar will always have its place, particularly as the efficiency of cells increases and new, more environmentally acceptable manufacturing methods are evolved, but, as with wind turbines, will always be ruled by availability of suitable weather conditions. To my way of thinking, we are dismally failing to do enough with tidal energy. There is a power source which is relentless and constantly available, regardless of weather..... assuming, of course, that our moon remains in orbit. It is said that a suitable barrage across the Severn Estuary in UK, for example, could virtually meet that nation's current power needs. And there are plenty of other places around those islands where tidal power could be harvested. Still, all this may be rendered obsolete in the very near future with multiple fusion power units and, for local area deployment, or even individual factories and houses, Quantum Energy Generators such as are said to be going into production in Japan sometime soon. Hopefully, they will arrive on the scene before our idiotic politicians start authorising "fracking" all over the place. We have got to get away from fossil fuels, come what may, otherwise we - that is my generation - have failed our children and future generations. Okay, I'll shut up now.
Bob Komarek
It's still highly inefficient and costly to operate. Since wind turbines and other renewable sources produce much less energy than fossil fuels, the U.S. is paying more for less. Coal-powered electricity is subsidized at about 5% of one cent for every kilowatt-hour produced, while wind power gets about a nickel per kwh. For solar power, it costs the taxpayer 77 cents per kwh.
Daishi
@everyone above. I provided a source for my claim ( http://en.wikipedia.org/wiki/Cost_of_electricity_by_source ) that wind power was fairly inexpensive and obviously there are different costs for different regions of the wold but could you guys who are disagreeing kindly reference a source? Wikipedia sources the Energy Information Administration from the Department of Energy. "Total System Levelized Cost (the rightmost column) gives the dollar cost per megawatt-hour that must be charged over time in order to pay for the total cost." That number also intentionally doesn't include tax credits or incentives it "represents the per-kilowatthour cost (in real dollars) of building and operating a generating plant over an assumed financial life and duty cycle" What that means is for all the people complaining about the costs of wind power I have provided a fairly authoritative source that you are wrong. The rest of the statistics from openEI, Germany, and France are largely in line with those figures so I'm inclined to believe they are credible. Here is OpenEI's Transparent Cost Database. The tab on the left is the Levelized Cost of Energy": http://en.openei.org/apps/TCDB/ Under "view data" on the bottom right you can see the current and historic publications used for their data so its pretty transparent. Based on ~2012 numbers they have on shore wind at $0.07 per kWh and Solar PV at $0.32 per kWh. They also collect publications of future projections so you can plot those in another tab. Based on those wind is expected to be $0.07 per kWh in 2020 and solar is expected to be $0.14/kWh in 2020 which puts PV in much better light but would still cost power companies more to produce energy than I currently pay to receive it.
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