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Posted

Drew Dowdell - January 19, 2012 - CheersandGears.com

One of the limitations of current wind turbine technology is the limited amount of power generated per turbine. Large scale installations are required to match the power output of just the smaller coal buring powerplant. The largest wind turbines in the world produce about 5mw of power while the average coal fired power station produces around 500mw. Simple math can tell you that 100 of the largest wind turbines we have would need to be built to equal just one coal power plant. The additional real estate and construction costs v. the fuel costs of coal and natural gas are a substantial hurdle in the adoption of wind power.

A new development from Japan shows a promising way to change the math. A scientist at Japan's Kyushu University has developed a simple addition to the wind turbine that can increase the power output between 100 to 200 percent. A curved ring called a "wind lens" installed around the outer edge of the blades disperses air away from the trailing side of the turbine. This has the effect of creating a vacuum behind the turbine that draws additional air through. The wind lens itself is made of fiberglass and is a relatively inexpensive addition to the turbine's construction. Additionally, existing turbines can be retrofitted with the wind lens, potentially tripling the output of existing wind farms.

post-51-0-48981000-1327014365.jpg

Going back to the math, the number of turbines needed to equal the power output of a coal plant drops from 100 to about 34. The largest onshore wind farm in the world is Roscoe Wind Farm in Roscoe, Texas. Rated at a power output of 781.5 megawatts, if retrofitted with wind lenses, could potentially triple output to 2,344 megawatts or roughly equal to two standard size nuclear power plants.

The wind lense has another benefit. It allows the turbine to start and operate efficiently at much lower wind speeds greatly increasing a turbine's baseline power generation. Low wind situtations therefor have a less drastic effect on power output.

How does this relate to automobiles? Plug in electric vehicles and plug in hybrid vehicles are still proliferating in the marketplace and their presence is expected to grow. Charging at home can have a noticable impact on a household's financial bottomline. Typical home wind installations cost roughly $8,500 before any tax credits and generate 3,000 watt-hour of power peak. Tripling that output to 9,000 watt-hours cuts a substantial savings into the average household using 11,000 watt-hours a month.

This new development in wind technology could mean that the wind would really be blowing your Nissan Leaf down the road.


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Posted

Considering the size of the wind turbines just outside Atlantic City, I'd say these wind lenses would need to be insanely huge and would limit the turbines ability to rotate to face the wind.

  • Agree 1
Posted

Actually, they help with directioning. But yes, they would be huge.

Perhaps when the wind is off by a few degrees, but I don't see how this will work if the wind is at a 90 degree to the direction of the turbine... so they would have to rotate with the unit. therefore, these must be huge AND lightweight. I don't foresee this holding up in nasty weather. Even the existing wind units need to be locked down in high winds. I'd think these wind lenses would require the entire windmill duck out of the weather somehow (space shuttle sized enclosure or a giant hole to drop into?) Worse, if the wind lens did flex or come loose and the turbine blades made contact, massive destruction would result.

I just think this will only work small scale... like home turbines.

Posted

Well another thing I didn't mention in the article was that these can be built much lee to the ground. All wind turbines today can rotate themselves. They have motors to do it for the exact reason you mention.

They are doing a test installation in japan now

  • Agree 1
Posted

this should have been realised much before now....

look at computer fans...the closer the blades are to the housing the better the flow.

it will add to contrction costs, but increase the ROI by a considerable amount.

Drew... should maybe watch your capitlization... MW is vastly different than mw. ;)

Posted
The largest wind turbines in the world produce about 5mw of power while the average coal fired power station produces around 500mw. Simple math can tell you that 100 of the largest wind turbines we have would need to be built to equal just one coal power plant.

*BUZZ* I'm so sorry, but that is incorrect. A wind turbine rated at 5MW has a peak output of 5MW, so the "simple math" is deceptive and wrong. The output has to be averaged out, because if the wind is too slow or too fast, the turbine doesn't produce at peak. Average output is generally more like 25-30% of the rating, so you're going to need more like 350 wind turbines to replace that 500MW coal plant. You can get 2, maybe 3 turbines per square mile, so if we're generous and go with 3, that's 117 square miles of wind farm to replace one crappy coal plant.

To add to the crappiness, the majority of these tons of turbines our tax money has been paying to put up aren't cutting edge 7MW, or 5MW turbines. No, they're 1-2MW units.

Anyway, let's say that this new design actually improves the effectiveness, and you can actually get an average of 5MW per hour out of a turbine. According to Wikipedia, "Primary energy use in the United States was 25,155 TWh". Since we're talking megawatts here, let's convert that over. 2009 electrical usage was 25,155,000,000,000,000 MWh. So with an average output of 5MW per hour per turbine (that's being generous - on top of the assumptions of the effects of this shroud, that would also be in at least a semi-ideal location for the turbine), we'd need 57,431,506,850 turbines to meet our energy needs. Which means 19,143,835,617 square miles of wind farm. Too bad the US is only 3,794,083 square miles. So if we covered every square mile of the US with wind farm, and we could assume that it would all run at ideal conditions, we could almost provide 2% of our nations power needs from wind power.

I'm all for continued research, and would love to see the day that these turbines put out ten time so more the amount of power they do so they can be relevant, I just do the math so that people will realize that wind is not, in the near future, going to save us from any energy crisis. It's also a waste that so much of our taxpayer money subsidizes wind turbines that aren't going toward research to make them actually meaningful, but to simply pad the pockets of big energy companies, who wouldn't touch wind with a 10ft pole if it weren't for subsidies.

Also, where I grew up is now in the middle of a huge wind farm. It has a certain interest to it, but I find that even as I just visit a week or two at a time, the interest wears off quickly. Especially at night, when all around you are dozens and dozens of syncronized blinking red lights.

  • Agree 1
Posted
The largest wind turbines in the world produce about 5mw of power while the average coal fired power station produces around 500mw. Simple math can tell you that 100 of the largest wind turbines we have would need to be built to equal just one coal power plant.

Anyway, let's say that this new design actually improves the effectiveness, and you can actually get an average of 5MW per hour out of a turbine. According to Wikipedia, "Primary energy use in the United States was 25,155 TWh". Since we're talking megawatts here, let's convert that over. 2009 electrical usage was 25,155,000,000,000,000 MWh.

Correction 1Tera Watt Hour = 1 Mega Mega Watt Hour. 25,155 TWh = 25,155,000,000 MWh

Posted

This wasn't an article about replacing all of our coal power generation capability with wind. This is about the coming need for additional power generation capability needed to power the ever increasing number of plug-in electric vehicles. Home wind generation that wasn't particularly affordable producing 3,000 watt-hours a month suddenly becomes a lot more interesting when the same installation at minimally higher cost produces 9,000 watt-hours a month.

Additionally, your point about 5mw peak is true, but coal plants and even nuke plants don't run at peak output all the time either and both can take time to ramp up the juice. As for averaging out the power output of the turbine to 25%, one of the points of the article is that with the wind lens, the turbines can operate at much lower wind speeds, so the amount of time the turbine spends generating electricity is increased. I don't know what the new percentage of peak is, but it is much higher than existing technology turbines.... and that is what I am trying to convey here. Baseline wind generation becomes higher with a wind lens.

The reason we have been installing the 1.5 - 2.5mw units is because we have the luxury of space in this country. The big 5 - 7 mw units are substantially more costly to construct because they are so much larger. Those are typically European installations. The mid-west from Texas all the way up through Canada is a veritable Saudi Arabia of wind energy. There is a lot of wind and a lot of room to put these installations in. There is a lot of room on the Great Lake to put in water based turbines.

As for the view, I don't know what your tastes are, but I find wind turbines much nicer to look at than a coal plant beltching sulfer into the air or nuke plant blowing off steam.

With this technology, the math changes for wind power.

Currently, not counting subsidies, but including captial costs and fuel costs, the breakdown for power generation is this:

Wind - $68/MWh

Coal - $67/MWh

Gas - $56/MWh (reflecting the recent downturn in natural gas prices)

That number for wind power is using today's technology. I don't know the number that would result from a wind lens installation, but you can see the potential for wind to suddenly become competative if it achieved only a 50% boost in output, much less the possible 200% increase.

Posted
The largest wind turbines in the world produce about 5mw of power while the average coal fired power station produces around 500mw. Simple math can tell you that 100 of the largest wind turbines we have would need to be built to equal just one coal power plant.

Anyway, let's say that this new design actually improves the effectiveness, and you can actually get an average of 5MW per hour out of a turbine. According to Wikipedia, "Primary energy use in the United States was 25,155 TWh". Since we're talking megawatts here, let's convert that over. 2009 electrical usage was 25,155,000,000,000,000 MWh.

Correction 1Tera Watt Hour = 1 Mega Mega Watt Hour. 25,155 TWh = 25,155,000,000 MWh

Good call, that's what I get for late night math.

The point still stands that we would have to litter HUGE amounts of land (and/or sea) with turbines for them to make any remotely noticeable contribution to our overall energy needs. Yeah, covering the entire plains area with turbines may sound great if you live on the coasts, but there are a lot of people I know who live in the area of the wind farm I linked to above that were sick of them within a year or two. Yeah, it can be interesting, but it gets old, and would even moreso if they were EVERYWHERE.

As for the view, I don't know what your tastes are, but I find wind turbines much nicer to look at than a coal plant beltching sulfer into the air or nuke plant blowing off steam.

If there was a need for 3 coal plants per square mile, I would certainly agree with you, but comparing one coal plant with littering 116 square miles with turbines, I'd rather have the coal plant (visually). Not that I'd want to live by it, but that's the thing, you can not live by the coal plant, you can't not live by the turbines without leaving the region.

On top of that, there is the ecological descruction of mass installation of wind turbines. How many mountains would need to be leveled to build enough wind turbines to provide 1% of the nation's power needs? How many gravel pits to make the concrete? What's the effect on the environment when you leave behind hundreds of huge concrete slabs after the turbines are worn out after 20-30 years? Or are we expecting that the power company will take them out? Or are we assuming the slabs will be reusable with turbine designs in 30 years?

I'm not anti-wind. I'm anti-cover-the-entire-plains-region-with-wind-farms, and I want people to realize the costs, and the potential (or lack thereof in many ways). There's gobs of propeganda that pushes wind as if it could save us & solve the energy crisis, but when you crunch the numbers (even with the math fixes above), at best it's a niche player.

Posted

Well another thing I didn't mention in the article was that these can be built much lee to the ground. All wind turbines today can rotate themselves. They have motors to do it for the exact reason you mention.

They are doing a test installation in japan now

Well, few small ones have directional motors... but I realize the big ones have motors... but my point is that if you add a wind lens, you are essentially adding a big sail... and you need a much larger motor to point the whole apparatus and keep it steady in shifting winds.

On the local wind farm, http://www.acua.com/acua/content.aspx?id=492&ekmensel=c580fa7b_20_88_btnlink, the wind lens would be about 250ft by 250ft... and would weigh... wild guess here... 40~50 tons... and its wind load would be astronomical in a storm... so now you need to seriously beef up the center support... a motor to control the rotation is just going to be massive.

I'm not sure you can get much lower to the ground (assuming thats what you mean by 'lee')... the best wind is high and having 100 foot blades sweeping close to the ground is its own hazard.

Do they have photos of the testing? I would like to see a real life photo of what they have in mind... and the exact scale.

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