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

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 [email protected]. 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!

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.