Don’t Expect Large Wind Plants To Provide A Lot Of Energy Yet

PaulShimel168x144My dad took me to the Western Electric open house at Hawthorne Works in Cicero, Ill., in October of 1978. Hawthorne Works was the premier design, development, and manufacturing facility for technology, electronics, and telecommunications on earth. It boasted total vertical integration.

The facility had its own rail yard, hotels, hospital, police department, beauty pageant, fire department, gymnasiums, orchestras, foundry, die shop, paper mill, printing presses, and power plant with enough headroom to sell power back to the utility (Fig. 1). It brought in raw materials and sent out switchgear and telephones with 90-year unlimited warranties and, at the time of my tour, two-thirds of the copper wire used on earth.


1. The Hawthorne Works in Cicero, Ill., once was the premier design, development, and manufacturing facility for technology, electronics, and telecommunications in the world.

That’s quite a statement. It was an even more impressive sight. The theme of the event was “Western Electric Hawthorne: Its Life And People.” As a kid I remember walking down the halls listening to the orchestra and watching 10-year-old, five-axis CNC machines make dies and intricate parts—in 1978.

I remember watching giant coaxial cable spoolers spooling cable that was copper ore and petroleum sludge a few moments prior with a network analyzer connected to the hub on a rotating solid gold connector tracking the impedance and return losses and correcting geometry as it spooled. It was on this tour that my stars cosmically aligned. I found my calling. It simply had to be electronics—power electronics, the stuff that makes it all go.

Unfortunately, WE‐HAW is no longer around. When Judge Harold H. Green swung the gavel in the early 1980s and ended “the Bell system” for being monopolistic, it all went away. Today the Hawthorne facility is a shopping mall, and a lousy one at that. Most any noteworthy structure was demolished.

There was a lot more to WE‐HAW than buildings. There was a spectacular, untiring work ethic in those confines that I simply can’t describe, a spirit that is the “life and people.” I grew up with this work ethic and I try to apply it as much as possible to subjects that impact power electronics.

Today’s Wind Farms

Have you ever driven past a wind farm? You see parts that you think are fairly large and grand moving at rates that seem slow and animated. When you walk up to one of the units (with permission, of course), you see things from an entirely different perspective.

In that regard, it’s a lot like WE-HAW. When you drove past WE-HAW, it looked like a big building with a lot of windows. But when you walked around the place, it was way more than that. Similarly, when you stand under a 2.1-MVA wind turbine in reasonable wind, it’s really amazing.

The tips of that blade don’t move slowly. They sizzle as they sail past. If you listen closely you can hear what a million foot pounds sounds like coming into the planetary gears on the gearbox. It isn’t as loud as an SD80 or a Dash9 rolling down the rails, but it’s noteworthy considering that the gearbox is enclosed and 300 feet up, and sound tends to propagate up.

The other thing that immediately sets in is the spread. It’s a long walk from one wind turbine to another. The curious mind can’t help but wonder how these machines are summed electrically and then distributed as well as how much output they deliver.

In the power seminars that I conduct on International Rectifier’s behalf, I like to take a look at these large wind turinbes and try to answer some of those questions as an introductory ice breaker. It’s not an ad, promotion, or marketing stunt. It’s just a few thoughts on how these things work and fit into our large-scale power needs. It makes the most sense to compare these fairly new renewable energy producers with more conventional power plants and then perhaps explore how these things fit into our aggregate energy needs.

The Lasalle Generation station in Lasalle, Ill., adjacent to the Grand Ridge windfarm, occupies about 2800 acres including the serpentine cooling lake (Fig. 2). The two boiling water reactors (BWRs) on the site were designed to produce a total of about 1700 MW of electrical power continuously. This means the power density of this plant is on the order of 600 kW per acre. That’s pretty dense. But what does that mean?


2. The Lasalle Generation Station in Lasalle, Ill., occupies about 2800 acres and produces 1700 MW, for a density of 600 kW per acre. Yet fossil fuel plants can produce 1 MW per acre, and a hydroelectric dam can yield 4 MW per acre.

Let’s take a look at a global level. According to a friend at ComEd, the world consumed about 139 x 109 MW*h in 2008. Over the course of the year, we consumed electrical energy at a rate of 15 million MW. If we take a look at the amount of land on earth, not including near shore wind farms, we have about 37 x 109 acres. If 10% of this were dedicated to producing the electricity that we need to live, thrive, and survive, that’s about 3.7 billion acres. The power density that we’d need from this amount of land to power the world in 2008 is then about 4 kW/acre.

If we look at large wind, the density that we see in the Midwest is on the order of one wind turbine per 50 acres. This seems low, but when you consider zoning, access roads, setbacks, ordinances, and natural set aside, it makes a little sense. The common wind turbine erected in these locations is a 2-MW unit. These turbines are available from Suzlon, Gamesa, GE, and several other companies.

The average wind speed in these areas is about 12 miles per hour. The cut in wind speed for these wind turbines varies a little bit, but it’s usually around 7 or 8 MPH. This is where power production starts. At 12-mph average wind speed, a 2-MW wind turbine makes about 200 kW. (It varies a little by manufacturer and blade design.) So getting back to power density, we have about 4 kW/acre for large wind farms in the Midwest.

For a sanity check, replacing the Lasalle “nuke” would take 8500 wind turbines at the average power rating stated above. In terms of land, that’s about 425,000 acres for an equivalent windfarm at Midwest U.S. yields compared to 2800 acres for the nuke. That’s a pretty big difference. We can tuck one away someplace quiet, and the other will be in our face.

For further consideration, a reasonable fossil fuel plant is about 1 MW/acre, and a photovoltaic (PV) plant can be as high as 100 kW/acre or so. Hydroelectric dams can be as high as 4 MW/acre not counting flooding, but rivers are usually scarce. The new initiatives to capture the power in waves on the oceans will have a power density somewhere between a wind farm and a PV plant, something on the order of 50 kW/acre from what I’ve seen.

From a first order standpoint, the power densities show that it might be feasible to power the world (at least as it was in 2008) entirely with clean renewable energy, but it would certainly change our landscape.

Other Considerations

But what of the workforce to build these things? Let’s assume it takes a 1500-man crew three years to build, certify, and commission a large nuke. Let’s also assume everyone works 40 hour weeks during that time. That comes out to about 9 million man hours.

On the large wind side, a 20-man crew needs a solid five-day week (assuming full daylight utilization or about 12-hour days) to erect and commission one wind turbine. For large wind we then have about 1200 man hours per wind turbine. Again, if we replaced one nuke with 8500 wind turbines, we’re comparing 9 million man hours to build and commission the nuke to about 10 million man hours to build and commission the equivalent wind turbines by Midwest U.S. wind yields. That’s roughly a wash in terms of labor.

As to the costs of the various solutions, large plants, especially nukes, are initially expensive. The upkeep and maintenance is minimal, though, as the solution lives out its useful life expectancy. Large wind turbines have lots of rotating parts that require maintenance and replacement.

Winergy, the largest manufacturer of gearboxes for large wind turbines, ships each gearbox with a two-year warranty. These gearboxes go into equipment that was purportedly designed for a 30-year serviceable lifetime. Replacing 35,000 pounds of gears nearly 300 feet in the air certainly doesn’t make the cost of ownership cheaper.

I’ve actually heard of curtail orders where utilities apply the brakes to a large wind farm on days with optimal wind due to the costs of maintenance and operation. Given those two data points, I’ve never heard of a curtail order being issued for an otherwise operable nuke.

As a first order glance, replacing all the nukes and fossil fuel plants with wind turbines and other alternates seems feasible, assuming we have that much prime land and are willing to tolerate the change in the landscape. I don’t see this as likely, though, since a traditional nuke can generate roughly 30 dB more power from an applicable parcel of land. It’s also clean.

Large wind turbines bear a large cost for maintenance and repair as well. Changing a gearbox nearly 300 feet in the air is a very expensive and dangerous operation, not to mention rotor bearings, thrust bearings, high-speed alternators, blade pitch motors, and yaw motors.

Large wind turbines do seem feasible, and the high-failure-rate technologies embodied at present will only improve with time. It seems like large wind is a good resource where it can be exploited, but it’s doubtful that it’s the one answer to all of our power needs.

More On WE-HAW

If the brief mention of WE-HAW has rekindled any old memories or curiosities and you want to see what the place really looked like before it was “busted,” there is a wonderful museum at Morton College in Cicero that does a great job capturing the memories and spirit of the place.

Tours are by appointment only. You can reach the museum at 708-656-8000, ext. 320, or by e-mailing jennifer.butler@morton.edu. I’d also like to thanks Tom Brandsness, the museum docent and a former WE-HAW employee, for providing the picture of the place. He’s probably the best tour guide the museum has!

Discuss this Article 21

greenew
on Apr 23, 2012
You kind of glossed over the point that the energy generated from a wind farm is renewable. A Coal fired or Oil fired plant is certainly going to provide a higher energy per unit area since the fuel is imported. Nuclear fuel is 'imported' too. Nuclear plants are clean, but what of the spent fuel? This is why we are not building this type of plant much, since environmentalist are rightly convinced that we don't have a sustainable answer to the leftovers. Has a Nuclear Plant ever been built in three years? Just try and build one now and see how long it takes. With political opposition, environmental studies, protests, law suites etc... you would be lucky to get one built in 10 years. Just look back to projects like the Diablo Canyon Plant in CA. What a mess that was.
diacad
on Apr 25, 2012
I agree with Paul Schimel that wind power will not efficiently satisfy energy needs, and that nuclear power must be revisited. As seen by some of the comments here, the nuclear option is tarnished by its bad safety record and other factors. But let's not throw the baby out with the bath water, only the uranium cycle. The thorium cycle does not present the safety, waste-disposal, or proliferation problems of uranium. Thiere is much on the internet about thorium. See http://www.cosmosmagazine.com/node/348/ for a start. Why isn't this discussed more widely? The main negative I see about thorium as a replacement for uranium is the enormous investments already made in uranium. I do not like the uranium cycle for many reasons. Even though the existing plants that cause all the problems are based on 40 year old technology, still the uranium cycle intrinsically involves more risks than the thorium. Thorium designs cannot explode, pose a large radioactive waste disposal problem, or be milked for bomb materials. In fact, during the Cold War, that was the rationale for uranium over thorium! Thorium reactors can actually "consume" existing old bomb material and radioactive waste, a plus since that is a big worry now. I believe nuclear power is the only really reliable and significant potential source of power, outside of fossil fuels. Wind and solar are not universally applicable, and not as "green" as nuclear. So we will be forced into it, sooner or later. Why not opt for a thorium cycle? The Chinese and Indians already have working thorium reactors. There have been experimental designs here as far back as the 50s, but nothing commercial. Sadly, the Obama administration has already started granting licenses for construction of new uranium-based plants, giving in to industry pressure. This may preclude development of the thorium cycle in this country. Expediency will deliver us another generation of what will become an old technology very rapidll
ynaught
on Apr 24, 2012
It's a lucky thing that nuclear waste is harmless and of no concern to us...and that nuclear power plants have no "rotating parts that require maintenance". This article seems over-simplified or misleading. As Dave points out, the 50 acres "used by" a single turbine is also used as farmland (from what I've seen). And, what of catastrophic failure? With wind turbines you get what, smashed soybeans? As a friend points out, Paul's logic can be used to prove that an electric clothes dryer is more efficient than a clothes line. The one sentence that bothered me most in this article (and drove me to register and comment for the first time here) was "It's also clean." This is thrown out as if it's been accepted for years. If it were clean, I could buy some nuclear fuel and build my own reactor! One could correctly say that "it is possible to contain the mess", but that's not the same as clean, nor is "it is possible" the same as "it is certain". It IS possible to have a catastrophic failure of a nuclear plant, even worse than the ones we've seen in our lifetime. It concerns me that for the sake of a bit more profit (or even an unforeseen incident), a nuclear plant could be allowed to fail. The idea that a wind turbine could fail does not worry me at all.
mmazzatti
on Apr 24, 2012
Paul, I'd agree with the other commentors I've read. The little research I've seen shows that a farm such as the 195 unit Maple Ridge at Tug Hill NY produces on the average over 40% of capacity and requires much less than 1% of the feed crop acreage it sits on. The other ignored aspect is the turbines will take dollars to days hauling them away for recycling, the nuclear plant decommisioning takes b-b-billions of dollars, and what is the half life of the containment carcass? Oh, and the night-tme power can be used to charge everyone's Volt!
paul.schimel@irf.com
on Apr 24, 2012
Greetings all. Thanks for the stir! All good points! The main point I wanted to capture was the poor reliability of the present wind turbine technologies and the notion that while renewable, if we decided to shut down all other means and power the world with these things, our landscape would probably change. I've spent a lot of time involved with the guys that fix these things. Listening to countless catastrophic gearbox failures. It boggles me that in a technology driven world we still have 40,000 pounds of gears on a stick some 300 feet in the air. Letourneau showed us that gears at low speed and high torque were a bad idea what?? a hundred years ago down in peoria? and we still do this today? We could hob them from intrinsically perfect titanium....don't matter. when that gust of wind belts 2 or 3 million foot pounds of torque into that little box full of gears, they break. Why not use a high pole count machine and eliminate the gears altogether? As to the nuke vs wind field density comparison, initially I was off--printer was found dead after making that mistake. apparently bubble jet cartridges fail, THEN leak all over everything. If you consider the area around lasalle, the wind blows a little harder. the power density is then 4 or 5 times higher....at the same time LaSalle is a lower density nuke. On the subject of the failures- that's horrific stuff. At one time I wanted to design nukes. I spent a lot of time studying the subject. Those engineers really did do a lot of work on that stuff--and they got it right by and large....but boy howdy, the exceptions sure are nasty. The last one in Japan is curious though....it was scheduled to be decomissioned in march of 2011....a deadline that is not comprimised.....just after than came the earthquake and the big wave.....perhaps all those secondary and ternary protection and containment devices were hauled off a week prior. What was the decommissioning procedure for a '71 nuke again? I bet there were none.....
cgallaway
on Apr 25, 2012
@wilton helm: The biggest problem with wind power is getting the wind to blow at rated speed (to produce rated output of generator) for 24 hrs/day 7 days per week for a few hundred years. Until that happens, wind will just not be reliable enough to be used as a main source of power.
paul.schimel@irf.com
on Apr 25, 2012
Hey Chris: maybe my learnin' is skewed, but last I checked cut in speed and cut out speed were two different things. SSDFIG can only add so much negative slip yes? thereby at some point the unit spins and makes nothing yes? above that point the power curve begins. All the books call that the cut in speed, but maybe they're all mistaken. As for cut out speed, I'm with ya there man. when the wind blows too hard pitch the blades, point into it, and ride it out. again with a little power electronics we could make that high pole count machine much more robust in those circumstances. as for power ratings.....did you thing I was going to hang a slot car motor up there? the appropriate sized high pole count machine will weight slightly more than the present SSDFIG, but it also eliminates all those gears. I've watched many of trailer leaving Winergy.....they come in with that arched preload, they leave flat with that gearbox on them. Those gearboxes are heavy. 35 to 40K pounds according to the datasheets.
kill the hacs
on Apr 24, 2012
paul schmiel your nuclear facts stink of radioactive excrement. 49 Japanese npp shut down as we speak, 4 decommissioned, and u still can't see the problem. Would your own families cancer convince you that radionuclide kill. now and 200,000 years from now? Tuck that away somewhere 'quiet" You are despicable and insane.
paul.schimel@irf.com
on Apr 30, 2012
And what then of the efficiency of the plant itself? I guess it depends on the specific Rankine cycle, reheat loops, etc, but numbers for this are on the order of 40 to 60% depending on the plant and design. If we cascade that, we are down to 20 to 30% net efficiency to charge that electric car....from the heat that is evolved by the plant to the energy into the battery. a small diesel engine with a turbo is a better deal at that point. clearly renewables don't operate in a rankine cycle with steam turbines, but are there other costs? it's interesting stuff. I enjoy the opinions and discussion....and if we qualify them all as being based on sound engineering judgement, we clearly have some thinkin' to do to solve these problems.
cgallaway
on Apr 25, 2012
@William Stein; perhaps you better learn a little about cut out speeds and wind speeds that will produce rated power. The wind speed that will produce rated power is roughly 20-25 mph. Cut out speeds are usually in between 50-60 mph. The cut out speed helps avoid damage to the blades from powerful storms. Also, a site with 12 mph 100 ft above ground will probably have that 20-25 mph wind at 300 ft above ground. Secondly, all the generators have to be rated for electrical production, you wouldn't want the generator to produce above it's rated power, would you?
ddrich
on Apr 24, 2012
Paul Typical wind farm in Nebraska has an annual capacity factor of over 40% or 4 times the output that the article stated. Also the typical turbine takes 2 acres out of production with the other 48 available for farming or ranching. In combination, these factors result in wind efficiency being 100 times greater than stated in the article
paul.schimel@irf.com
on Apr 25, 2012
getting back to my note below, If most of the present wind turbine technologies rely on the SSDFIG, super synchronous doubly fed induction generator operated with resistors switched in series with the shorting bars to add negative slip and spread the power band of the machine.....this can clearly be improved upon with power electronics. For example, use a high pole count syncnronous machine, such that the gears are no longer needed. Rectify the energy from the machine, then process this with an inverter back to the grid. Cut in speed can drop dramatically perhaps to zero, and all those gearbox losses are now avaialable at the drive shaft as added power which will outweigh the added overhead of processing that power at least tenfold. Keep the same over rev precautions including braking, blade pitch control and yaw control and we have a good solution. retrofit the existing stuff and all those machines that used to sit on the hill and NOT spin during high winds will spin again. When the production tax credits run out and the accountants step in, we'll be talking about this stuff in detail. Replacing those gearboxes isn't free! If I apply the stuff that I observed at WE way back then, that seems to be a decent path. Rather than heating up all that 360SAE weight oil, having to cool it, and worrying about leaks to keep that gearbox happy, use the right tool for the job--try a high pole count machine. EVT is doing some revolutionary work along these lines.
wileyb
on Apr 25, 2012
Wind power is definitely different than nuclear, but the differences can be advantages. Wind plants can be distributed over a large area, thus minimizing the disturbance for any one area. This also saves on distribution costs - in my area distribution is about the same cost as that of generating the power. Wind tends to produce more power in the night, thus complementing solar, which produces more during the day: together they have a much better load coverage. Yes we still need other technologies, but wind and solar can augment existing conventional plants in a more sustainable way then just constructing more of the same old thing. One final thought, why not let the marketplace decide? Solar manufacturers have offered to give up all subsidies and challenged oil and nuclear to do the same (all subsidies, not just tax credits but subsidized insurance, etc.) So far no takers from the oil and nuclear industries.
paul.schimel@irf.com
on Apr 30, 2012
I realize that forums, blogs, etc don't actually solve problems, but we can sure as heck discuss.... so we talked about conventional power plants, a discussion that was sorely needed by the comments. I've actually delved into this with several groups of energy auditors, plant managers, and senior engineers. The stats are amazing. Whether a nuke, windfarm, PV farm, or fossil fuel, every group is absolutely convinced that their solution is the cheapest, the best, and the brightest with the smallest carbon footprint. And they can cite stats all day long to that end. This makes me wonder where the truth actually is. For example, let's say I hop in that electric car, drive it home and plug it in. perhaps the efficiency of the charger, with it's cascaded PFC and DC to DC converter is 95%, which is surely platinum on the marketed "80 plus standard", so that means it's really good right? Then the efficiency of getting those electronis from the plant through the transmission lines, substations, transformers, etc is then probably about 66% depending on where you live. And then the battery gets hot, which makes me wonder just how much of that energy is stored vs what is dissipated. let's say it's 80%. If we cascade that stuff, the net efficiency is on the order of 50%. Why is that percieved as a good deal? In other words, what if we radically changed power distribution to a point of load model and eliminated all of those T and D losses? what if we all had smaller scale renewables, microturbines, gen sets, EV inverters, etc in our barn?. OK, that's a complex world...even for a gearhead-tech junkie, but it would eliminate lots of losses and allow a much more flexible power machine. I fully expect arguements on causality, stability, reliability, faults, etc, etc......but based on what the 'big plants' are doing these days, perhaps it's time to ask those questions. When I see the big plants involved with the smart grid initiatives, I wonder how smart that really is?
maxhendrickson
on Apr 24, 2012
I'd have to agree with Mr. Young. Unless you believe in perpetual motion machines, energy has to come from somewhere. If energy is extracted from the wind, the wind has to slow down (affecting some other things) which are unknown to us as now. Everyone (at least most everyone) seems to be concerned with global warming. Let's extract energy from there and cool the planet down. If I would know how to do this, I'd be on my yacht, somewhere warm, sipping a cool one. Max Hendrickson
wstein25
on Apr 23, 2012
Paul, Nice "big picture" review. But please get an introductory text on wind power before making estimates on turbine power production. It's not that hard but you got it all wrong. Also, as per your previous commenter, it's doubtful any developer would site a wind farm at a 12 MPH site. "Low hanging fruit" that is areas with much higher average wind speeds will be developed first, other aspects being equal. As to power production, the power available in a moving mass of air is proportional to the cube of the wind velocity, so wind speed makes a really big difference. Also you can't just take the average, you need to look a histogram of wind velocities and then use this to determine the total annual production. With all due respect, please pull this article down, and "do over".
StephenFCYoung
on Apr 23, 2012
just a question: How many wind turbines does it take to start influencing the weather? It takes energy out of the system, therefore something has to be affected eventually, right? And if you think it will never happen, I have some Newfoundland Grand Banks cods to sell you...
cgallaway
on Apr 25, 2012
Personally, I think that if we can dig a few miles down for oil, then we can do so for geothermal heat. At what cost, though, I don't really know. Perhaps re utilizing old strip mines would allow a plant to be built in the below the surface so a few hundred less feet of drilling is needed. Overall, geothermal can be on 24 hrs a day, 7 days per week, shutting down only for routine maintenance. Solar is the next best on my list of renewables. Wind is way too intermitten and concentrating a large amount of wind onto a distribution system has a lot of unintended consequences like voltage rises (due to the loads being closer to the source), multiple sources(networking power flow), Line capacity (based on power factor reduction), Power factor reduction (based on large amounts of KVAR needed for some (not all) types of wind towers),voltage collapse (based on power factor reduction) and let's not forget about the transient instabilities of the system and multiple sources of fault current in our system protection schemes. I am concerned about nukes, as everyone else points out, what to do with the spent fuel? I think Coal can be burned cleaner than what it currently is. I don't mind the burning of garbage. And I am curious about the idea of burning solid feces as one would coal and also burning the methane that builds up in the waste treatment facilities. Burning the biological waste won't give us all the energy we need, but it could help municipalities with sewer systems (as opposed to rural areas) a chance to produce some of what they would otherwise use.
markjmckelvey
on Apr 25, 2012
Its also clean? Try telling that to the people that lost their homes in Fukushima. I've never heard of anyone worried about cancer because they lived within 25 miles of a windmill.
paul.schimel@irf.com
on Apr 10, 2012
I must have printed the NREL maps in the wrong color scheme. The average wind speed for the midwest is a little higher than 12MPH. it is closer to 18MPH. This raises the yield of the wind turbines to a much more substantial 500 to 800KW and changes the calculations slightly. But take careful note....these winds blow harder at night, when we don't need the energy. Storage remains a problem. I suspect the data in the article is actually close when we consider this. Paul L. Schimel
whelm
on Apr 23, 2012
There are other bits and pieces that need to be in the picture. For instance, for a coal fired plant, the acreage needs to include the (strip) mine the coal is coming from (and it's impact on the landscape). A nuclear plant needs to include waste storage and disposal acreage including the fact that the energy was extracted in a few years, but the waste remains hazardous for a few centuries. Plus I personally am strongly opposed to any addional use of nuclear until a permanent waste solution is in place, which is a major political hot potato -- "not in my backyard". Nevada hasn't agreed ;yet to adding it to their list of sanctioned "sins". What are the "materials" and "waste" factors of wind power? Those worn out gear boxes presumably can be melted down and recycled into new ones. Not much else to dispose of. I think part of the solution is more emphasis on smaller scale units. I wouldn't mind a 5 or 10 KW unit on my property. It is three wooded acres and I could place it in an out of the way place, just above the treetops where it would be hard to spot. Some designs don't even need orientation, They rotate in a vertical plane and catch wind from any angle. Such a unit would probably meet my needs most of the time, backed up by the grid, and backfeed excess during peeks.That is called sustainable.

Please or Register to post comments.

Newsletter Signup

Forums

Search Parts

 

powered by:

 

 

Newsletter Signup

Connect With Us