Trent Brome writes on his Facebook page:
Arlington, WY – avg annual wind speed of 31mph, gusts above 110mph, seems like a great place for a wind turbine ….right?
Photos from Feb 1, 2011 as the cold air mass that formed Snowzilla barreled through. The wind chill in the area from yesterday was extreme, -54F !!
0453 AM EXTR WIND CHILL PUMPKIN VINE 41.05N 105.46W 02/01/2011 M-54.00 F ALBANY WY DEPT OF HIGHWAYS
A new record low was set in Cheyenne:
RECORD EVENT REPORT NATIONAL WEATHER SERVICE CHEYENNE WY 523 PM MST TUE FEB 01 2011 ...RECORD DAILY LOW HIGH SET AT CHEYENNE WYOMING... A RECORD DAILY LOW HIGH WAS SET TODAY AT CHEYENNE WYOMING. THE OLD RECORD WAS MINUS 5 SET IN 1899. THE NEW RECORD LOW HIGH IS MINUS 9.
Combine cold temperatures that make steel brittle along with gusty winds, and you have a Titanic recipe for disaster. For those that will argue that I’m being unfair to the promise of wind power, I welcome you to provide photos of any power plant in the USA that has been collapsed due to weather. Downed power poles sure, but power sources?
h/t to Eric Nielsen for the photo
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UPDATE: While the Facebook page source of these photos shows them dated yesterday, Feb 1st, it appears the event actually happened November 25th. A similar photo here:
http://www.windaction.org/pictures/30961
The same author, Trent Brome, submitted them. It is unfortunate he did not make note of the correct date on his facebook page, and given a strong storm had just passed, I had no reason to expect otherwise. I apologize for not checking further. Thanks to V Marti for pointing out the other website link above. – Anthony
@Tom February 2, 2011 at 1:36 am:
From those pics I would agree, the top of the tower door does look like it was involved, possibly in a primary way. The “ring shape” from bottom of the door to top of the door is certainly a weak area, if not beefed up/stiffened.
As you would know, engineering design so often assumes the shape of a structural member retains its shape. The minute the shape is compromised the formulas don’t work as advertised. The side load from the wind is certainly what took this down. Internal stiffening rings would seem to be a decent and cheap way to make sure the shape is retained. The other more expensive way would be to enlarge the diameter at the base.
You can see by the number of anchor bolts how much force the tower is designed for. Those are probably 3/4″ anchor bolts, and it looks like about 40 of them around on about 6″ centers. With that much lateral force, stiffening rings should have been used. The photos don’t exactly look like any were used.
It is hard to tell, but I can’t see any actual thickness to the steel plate used, so for some reason that suggests like 1/4″ or perhaps 3/8″ was used. If so and they were counting on that, the thickness seems pretty dicey to me. But that observation is flimsy by me, based only on what I can make out from the 2 pics. But an online search didn’t turn up anymore pics.
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As to those who point at the cold, a UK web page at http://tiny.cc/oqfda should provide some perspective.
Arthur, that was baaaad!
“Derek Reynolds says:
February 3, 2011 at 4:44 am”
Yes you are right, wrought iron was used not steel. But, along with the unsealed bulkheads (Unsinkable? I mean a series of wrought iron boxes, riveted together, with the lid missing, unsinkable?), an arrogant captain, a fast ship equiped with a small rudder, the rivets failing were the main cause. Actually, no, cost cutting was the main culprit.
TBH I didn’t notice the door at the bottom of the tower but it seems to be a standard design to me, certainly similar to all others I’ve seen. I wonder is any computer models were used in the design phase for stress testing. Like in the auto mfg industry, there are many computer stress simulations done these days, as well as actual crash tests. Maybe we need a “save wind turbine towers” levy? As far as I know, the Koreans make the best quality steel.
PS. The towers should be made out of carbon fibre, it’s much much stronger than steel.
Regarding the “strength” of steel and other materials:
Glass: mechanics and technology: indicates the calculated strength of glass at 16 GPa http://books.google.com/books?id=oSN-XMuDj5wC&pg=PA135&lpg=PA135&dq=theoretical+strength+of+glass&source=bl&ots=0BHnY9V0DV&sig=gLYFab38N9iWFHXFZKdR_4rc78k&hl=en&ei=5PdLTcOeH470swOmm8WZCg&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCQQ6AEwAg#v=onepage&q=theoretical%20strength%20of%20glass&f=false, high strength steel is near 3 GPa.
Of course, wiki has articles, such as http://en.wikipedia.org/wiki/Strength_of_materials.
And, yes, carbon fiber is stronger, near 5 GPa, but the problem is brittleness. A carbon fiber breaks like glass. That is why glass is a poor structural material. That is why we use glass and carbon fibers in composites, to take advantage of the strength and mitigate the brittleness with the bulk material. It doesn’t always work as we’d like. Nano carbon tubes (Fullerenes) are different. They are potentially super strong, but it is still carbon. Last I checked, carbon is highly reactive with most elements, especially oxygen. 😉
While brittle is bad, strong is good. Generally you get one with the other. There are exceptions. It must all be balanced to give the best combinations for the intended application.
Kum Dollison says:
February 2, 2011 at 2:48 pm
“Southern California Edison has selected 250 MW worth of solar bids from companies able to produce solar electricity for 20 years for less money annually than the 20 year levelized cost of energy of a combined-cycle natural gas turbine power plant.
Southern California Edison buys 20 years of Solar for less than the levelized cost of nat gas:
http://cleantechnica.com/2011/02/01/sce-buys-20-years-of-solar-power-for-less-than-natural-gas/
They could have purchased ten times as much if they’d wished.
We seem to be looking at something under $0.11 kwh.”
Thanks for the link to what SCE is doing in regards to meeting the 33%RES by 2020. Their approach to putting PV in locations near their distribution and transmission (and close to their customers) lines seems like a more total cost effective way to get electricity their customers than PG&E’s recent contract to purchase electricity at a large PV installation in NV-Boulder City noted here- http://www.greentechmedia.com/articles/read/Sempras-Copper-Mountain-is-Now-the-Largest-PV-Plant-in-U.S/
We put a PV system in at our little ranch back in 2006 and have been very happy with it (last month- an unusually sunny Jan- we produced close to 600 kilowatt hours of energy with our 6.12 kw system). I assume that the folks putting in the PV systems are (or will be) under contracts, which are confidential, similar to how our Feed In Tariff works. The investors in the systems signed 20 year contract with SCE to provide electricity at a price based on when they send (time of day and likely time of year- i.e. summer and winter) to the grid. Your comment on the average price for what the investors of the generation will receive sounds about right (11 cents). In the winter I get a credit (vs. $) towards my yearly PG&E bill of about 12.94 cents per kw/hr that I send back to the grid during peak times.
You may recall that PG&E went bankrupt back in the early 2000’s during the energy crisis we had here in CA (that Enron had a lot to do with). There was a perceived generation capacity shortage back then and that concern held till mid 2006 as I was able to secure an E-7 net meter from PG&E in 2006. As a generator of electricity for the grid PG&E pays me (opps credits me) a bit over 30 cents a kw/hr in the summer high demand peak times for the energy I can send them. The folks providing SCE will be getting a premium for the energy they are providing SCE at peak times during the summer too. Not likely .30 by likely around .20 or so.
I used to get a 10 to 20 page summary of the allocated costs from PG&E for my monthly bill/usage. Needless to say it was more then a bit painful to figure out all the allocations I was charged (or credited for once I became a generator). I have enjoyed summer electrical prices from PG&E ever sense I put the our PV system in. As I noted above we get a bit over .30 a kw/hr for the electricity we send to the grid at peak time in the summer with our 2006 version of a smart meter. The dynamic pricing schedule that we have was enabled by a smart meter. What I found interesting I reviewing those detailed bills I used to get from PG&E was the breakdown of all the costs. I live very close to a few small to medium size hydro plants so my cost breakdown may be different then other customers of PG&E.
The breakdown of the allocated costs I paid PG&E for a years (7/08 to 7/09) worth of energy is as follows:
Total KW used (2008-9) 17156
% from PV 55.18
7/2008 to 7/2009
Billing Category $ % of bill
Transmission 77.3 19.55
Public Purpose 71.56 18.10
Generation 143.41 36.27
EC tax 1.71 0.43
Energy cost recovery 22.12 5.59
DWR bond 37.3 9.43
ongoingctc 39.88 10.09
nuc decomm 2.11 0.53
Gross bill 395.39 100
Distribution -92.4
Net bill 302.99
What I found amazing from my bill was how little, percentage wise, the generation part of getting electricity to me was of my total costs. PG&E recently acknowledged (in their 2011 General Rate Case comments to the CPUC) that their increased costs over the last few years (actually since they started with the 5 tier progressive rate structure in 2005) was allocated to Tier 3, 4 and 5 users in their system. From now on they will be allocating their costs across more tiers (including Tier 1 and 2). If we assume SCE costs are 50% for generation currently then for them to sell a kw/hr of energy to a SCE user they need to charge over .22 a kw to cover their costs. If they are paying the generator of the PV generated electricity a premium in the summer during peak times their costs will be higher. You can see why smart meters are needed to allocate these extra costs to users at peak times.
If you happen to live in SCE’d service area I would highly recommend looking into generating some of your own electricity if you can. The rebates from SCE are still fairly high (they are really low in PG&E’s territory now) as someone is going to have to pay for the premium pricing that SCE is going to be paying the generators of the new PV you noted in your post.
People who suggest that one should make the towers out of carbon fibre (CF) instead should first look at the cost of materials for the amount of load carried, then the cost of manufacture, the means of assembly and then the vastly different material properties which will mean that a CF tower will be much stiffer than a steel one and more slender for the same strength and quasi-static deflection. Depending on the other composites employed and the way in which they are “woven”, there could well be less dissipation of energy within the material which means that the structure will be sensisitve to largely undamped vibrations. Extra costs to nullify those effects.
As a point of reference, ask Boeing how much it a fuselage of a Dreamliner costs to make and how long it takes to make it. How clean the manufacturing environment has to be. What is involved in joining CF components in a structurally-sound, corrosion-resistant manner.
The solution to a flawed design is not the use of an expensive, esoteric material. One identifies why the structure failed and builds a better one … which in a proper design process often leads to a cheaper implementation that works better. That’s what real Engineers do; being the Olympians of applied sciences. (Now where the emoticon showing tongue slighlty in-cheek?)
Without massive federal subsidies, wind does not work. Only thing worse is solar. I with a group of others tried to put a wind deal together, and the only thing that made it remotely interesting is that the power company offered to buy power from us at $.09 kilowatt. They sell it for about $.14 a kilowatt. It was marginal at best at this price considering the cost an installation, AND the huge maintenance cost of a turbine. And the only reason that it was .09, was that the state mandated a certain percentage of power come from “green” technology. Otherwise the power company was paying $.03 per Kilowatt from normal power plants. Well friends and neighbors, guess who gets to pay for that good green wind power. Look at your electric bill, just another form of government folly and tax.