I receive every month a very interesting report from the Venezuelan Academy for Engineering. It always has interesting facts, I particularly enjoy the pictures of unfinished public works by the Chávez Government.
In the latest report, which I got yesterday, there is this graph of the position of the turbines in Guri
As shown, eight of the Guri turbines (two of which are down) that generate 5,600 MW are at level of 238 meters, thus it would be impossible to operate at that height as said publicly by at least two Government officials. One of them actually said that it could operate at 236 meters. Note that there are six additional turbines at the lower level which are down.
The problem is that there is a phenomenon known as cavitation which damages the turbines. As the water level goes down, air bubble can gon in the turbines. These bubbles themselves are not the problem, the way I understnd is that as they collapse inside the trubine they create pressure waves which are at high frequency which lowers the efficiency and damages the turbines. The Guri dam specifications say that it should never be operated below 240 meters, but more importantly the specs say operation should be stopped even above that level.
An additional plot form the same presenttaion, not in the Bulletin of the Academy is shown below:
This plot shows the scheduled “new” capacity to come online in the next three years. As you can see Corpoelec projects new capacity in the next three years slightly above 4,000 MW, the same amount the Government claims it will install in the next 12 months. Note that this includes 400 MW of Planta Centro, which were scheduled to come online last October, then last February and now who knows when. Hopefully, the rest of the schedule will be more on time that repairing 400 MW of Planta Centro.
Today, the OPSIS website reports that inflow into the Guri dam jumped to 919 cubic meters per second, a sharp increase over the previous days. The water level dropped 14 centimeters, but it indicates there is significant rainfall in the Caroni basin. This is good news.
The Devil's Excrement 
April 8, 2016 at 7:10 am
I am actually happy to glance at this weblog posts which includes tons of helpful data, thanks for providing these information.
March 13, 2016 at 11:56 pm
[…] The question is how bad the problem is or may become. To explain this, I resort to slides I showed in 2010 when a similar threat was present. […]
April 3, 2010 at 10:40 pm
Miguel:
Take a look at this graph which appeared in ND:
http://www.imagebam.com/image/d8e1b474839565
ND link:
http://noticierodigital.com/forum/viewtopic.php?t=625097&postdays=0&postorder=asc&start=735&sid=c08da9ad2adc4c01c9372306df6a539b
March 27, 2010 at 11:03 pm
Miguel:
Check this link with an article of an upgrade programmed to be done to the Guri Dam, starting in 2006 (on page 14). This could explain current maintenance being done at Guri dam:
Some Excerpts:
Rehabilitation contract for five 700 MW Francis turbines in Venezuela
… The daily energy production of both powerhouses corresponds to
almost 300,000 barrels of crude oil and covers approximately 45 per cent
of the entire electricity demand of Venezuela, which with a population of
26 million and huge, sparsely populated regions is one of the larger states in South America. The quality and reliability of the original
equipment, which had been supplied by a Japanese manufacturer, no longer satisfied the state-owned customer, CVG EDELCA. Efficiency was poor and regular intensive repairs were necessary in order to maintain unit operation.
Therefore, in 1998 the decision was taken to carry out a fundamental rehabilitation. The aim was to bring efficiency, vibration, maintenance and reliability to the levels necessary for a safe and reliable electricity supply
….. It took until December 1, 2006, until all the contractual documents were ready for signature. Then on December 1, 2006, the contract was formally signed at the public notary’s office in
Puerto Ordaz ..
The three turbine runners to be supplied by Andritz VA TECH HYDRO
will be manufactured in the company plant at Ravensburg / Germany, a
location that has experience and now-how with all types and sizes of
hydraulic turbines dating back 150 years. As is current common practice
when manufacturing large Francis runners, a welded design has been
chosen, using cast components in martensitic stainless steel. Blade
machining will be carried out on a CNC milling machine prior to welding.
The disassembly and installation work on the Guri site will be performed
under the supervision of the installation specialists from Ravensburg in close cooperation with the consortium partner and a local company.
The total contract period is 69 months, or almost 6 years. The first runner is to be shipped to the site 28 months after the commencement of the contract and all rehabilitated turbine units will be commissioned from 2010 – 2012.
The realization of this sustainable solution ensures that the turbines,
which are of great importance to a secure national power supply, can
be operated for several decades with improved operational behaviour
and the highest efficiency levels.
Click to access hydro-media-customer-magazine-hn11_en220507.pdf
March 26, 2010 at 1:13 am
Just a simple explanation, cavitation is produced when liquids reach their vapour pressure (due to the low level in the dam) and then the liquid molecules change from liquid to vapour as in bubbles. Then these bubbles travel to a higher pressure area inside the turbine, imploding and then returning to liquid scratching or eroding the metal in the process…
March 25, 2010 at 12:10 pm
Prof. Zarea was brought from Rumania in the late 70’s by Prof. Georgescu (not related to Dictator). Georgescu led an expedition in the mid 80’s to prove that it was possible to navigate from the Orinoco River in Venezuela to the Plata River, in Agentina.
Current predictions based in data from 2-Dec-09 to 23-Mar-10, using Excel 2000:
Polynomial Trendline
Date Square Cubic
25-Mar-10 250,95 250,76
26-Mar-10 250,80 250,60
27-Mar-10 250,64 250,44
28-Mar-10 250,49 250,28
29-Mar-10 250,33 250,11
30-Mar-10 250,17 249,95
31-Mar-10 250,01 249,78
1-Abr-10 249,85 249,62
2-Abr-10 249,69 249,45
3-Abr-10 249,53 249,28
4-Abr-10 249,37 249,11
5-Abr-10 249,21 248,94
6-Abr-10 249,05 248,77
7-Abr-10 248,88 248,60
8-Abr-10 248,72 248,43
9-Abr-10 248,56 248,25
10-Abr-10 248,39 248,08
11-Abr-10 248,22 247,90
12-Abr-10 248,06 247,72
13-Abr-10 247,89 247,55
14-Abr-10 247,72 247,37
15-Abr-10 247,55 247,19
16-Abr-10 247,38 247,01
17-Abr-10 247,21 246,82
18-Abr-10 247,04 246,64
19-Abr-10 246,87 246,46
20-Abr-10 246,70 246,27
21-Abr-10 246,53 246,09
22-Abr-10 246,35 245,90
23-Abr-10 246,18 245,71
24-Abr-10 246,00 245,52
25-Abr-10 245,83 245,33
26-Abr-10 245,65 245,14
27-Abr-10 245,48 244,95
28-Abr-10 245,30 244,76
29-Abr-10 245,12 244,56
30-Abr-10 244,94 244,37
1-May-10 244,76 244,17
2-May-10 244,58 243,98
3-May-10 244,40 243,78
4-May-10 244,22 243,58
5-May-10 244,04 243,38
6-May-10 243,85 243,18
7-May-10 243,67 242,98
8-May-10 243,48 242,77
9-May-10 243,30 242,57
10-May-10 243,11 242,36
11-May-10 242,93 242,16
12-May-10 242,74 241,95
13-May-10 242,55 241,74
14-May-10 242,36 241,53
15-May-10 242,17 241,32
16-May-10 241,98 241,11
17-May-10 241,79 240,90
18-May-10 241,60 240,68
19-May-10 241,41 240,47
20-May-10 241,22 240,25
21-May-10 241,02 240,04
22-May-10 240,83 239,82
March 24, 2010 at 12:15 pm
And, although not from Electrical but from Civil Engineering, an Hydraulics eminence, Julian Aguirre (disclosure: my uncle)
March 24, 2010 at 11:27 am
Reading about USB professors I remember our own in ULA (Power dept): Flor Velasco (one of two ladies teaching in the Electrical school), Pedro Mora, Hildemaro Briceño, Henao, Carlos Romero (this guy is a genius, a colombian, graduated with honors in USA, both BSEE / MSEE)…
March 24, 2010 at 11:07 am
BTW: a “turbo esclavo” was usually a single student per quarter, promptly chosen by Zarea in the quarter’s first day of class to run class-related errands for him (an unofficial Teaching Assistant, if you will). Since Zarea had an hernia (at least when I took his class) this person (“turboesclavo”, rather) would be asked to go and grab parts and other show and tell pieces from his office and to the classroom and run other class-related errands. This “ordeal” would last the entire quarter, but as far as I could tell students obligued willingly since Zarea had a knack for making it a long (a three month long, in fact) joke. And yes, his tests did take ~ 8 hrs, which included a intermission right about half way through for lunch. This was the first time (in my life) that it was “legal” for me to refer to any class notes, books, etc. during the test. Zarea also taught a Solar Energy elective, which I didn’t take. He was preeminent in the Fluid Mechanics field, where he had created the wing profile (perfil de ala) with his name.
March 24, 2010 at 10:55 am
In a “normal” country it takes years, no months to install any serious amount of power generation (hundreds of megawatts). In Venezuela, which is in its own league, it takes months. Of course, with the track record of this regime, in most cases it really takes infinity (as Miguel mentioned above, and has mentioned quite a few times in different postings) many (most, perhaps) projects are never finished. What we also know is that, for sure money will be spent, and will end up in a reduced set of people’s pockets (perhaps in banks of Andorra, which I believe Miguel has also blogged on in the past).
March 24, 2010 at 6:30 am
The next interesting question then is
— assuming that all the foreign exchange reserves claimed by the Central Bank of Venezuela are really there — (you can borrow reserves or they can be hard to actually use — like gold) — about $29 billion —
–and assuming that the government is willing to spend whatever it takes —
How long does it really take to install and get all of the new plants effectively operating? It’s one thing to sign some papers in Germany — it’s another thing to actually have it connected to a functioning fuel supply, have trained personnel, and have it effectively integrated into a national grid. My understanding is that if you wanted to do this in Norway you would be talking about a normal time horizon measured in years rather than months.
March 24, 2010 at 5:41 am
I hear last week from the German Handelskammer that there are a few officiales of the venezuelan government in europe, desperate to buy power generation…
Interesting point, they even ask for solar power…
Just maybe a little too late?
March 24, 2010 at 5:39 am
Can’t the Belarusans repair the turbines immediately?
Wait–I just pee’d myself laughing.
March 23, 2010 at 10:34 pm
Mike and others: Thank you all for your contributions, I really learn from all this and have a better idea. Looking better but not out of it and 2011 is when we really will have to face the music.
March 23, 2010 at 10:26 pm
I did some more data digging, which resulted in some good news and some less good news (mainly based on publications from Lewis & Saunders in the 80s and Edelca’s website):
+ Average reservoir evaporation is reported at some 6 mm per day. This is equivalent to some 2.5% of average inflow rate from the Caroni and therefore does not have a major impact on the level drop.
+ The blackness of the water is created by dissolved organic matter, not by suspended solids. The suspended solids concentration is exceptionally low for a river system, at 10 mg/l. Even if all the suspended solids would deposit in the lake, the lake fill would still be less than 1 mm per year, i.e. negligible.
– Edelca reports supply of 700 m3/s on the 18th and a jump of 900 m3/s is not enough. Average flow of the Caroni for the month of March is 1250 m3/s. Inflow is still below normal and offtake is above normal, due to inefficient power generation at a water level of 252 m.
– I made a simple model using average monthly supply and a constant demand. This indicates that we will start 2011 some 10 meters below where we started this year and will reach the critical period in March, rather than May. Edelca shows an even more alarming scenario with a critical period from Nov 2010 – Abr 2011.
Thanks for the additional info.
March 23, 2010 at 10:23 pm
Nope, León, in my case. But then I’m not a mechanical eng. buzzard, I actually knew how to program in RPN.
March 23, 2010 at 8:42 pm
Ok lets see if some of those Usb engineers belonged to the “turbo esclavos” club….
Prof Zarea came from Rumania in the late 70’s and teached FLuid Mechanics and Energy Conversion to many Usb Engineers.
February 2, 2013 at 6:21 pm
Prof Zarea passed away yesterday…
March 23, 2010 at 7:57 pm
Panadería El Placer
March 23, 2010 at 6:57 pm
If run for a period of time, cavitation will erode the turbine blades, rendering the entire turbine useless. Repairs costs will be enormous as well as the turbine off-line for a long period of time. They are playing with fire.
March 23, 2010 at 6:19 pm
There is a good article on cavitation in Wikipedia where they show a picture of a Francis turbine damaged by cavitation. This is the type of turbine installed at Guri.
March 23, 2010 at 5:56 pm
cricri +milk chocolate with roasted rice, made by Savoy
Canilla=pan de canilla/ pan frances.
Stephan Zarea had a liking for buying a canilla, and stuffing it with chocolate. He credited that was a great way to read through his famous 8 hour long exams…
One of the best teachers I had at my undergrad at USB. (conversion de energia!)
Un fuerte para el que descifre “The Pleassure!” jaja
February 2, 2013 at 6:20 pm
Professor Zarea passed away yesterday…..
February 2, 2013 at 11:49 pm
I am sorry to hear this. He was good for Venezuela.
March 23, 2010 at 3:17 pm
High levels for Guri = Good
Completed public works = Bad
Probably since you rely on electricity more than public works. Kind of twisted that you get a kick out of people being deprived of public works! Or is it the wasted taxpayer/oil money that puts a smile on your face?
March 23, 2010 at 2:55 pm
That is a very interesting chart of the actual orientation of the turbines as related to elevation. Seems like in a country where you know you will have a dry period each and every year, you would focus repairs on the turbines which operate in the lower portion of the table. I must be missing something.
March 23, 2010 at 1:33 pm
LuisF
….sorry PSF! do you homework!!!
Expecting PSF to do their homework and be knowledgeable about what they discuss is as fruitful as repealing the second law of thermodynamics in order to build a perpetual motion machine.
March 23, 2010 at 1:27 pm
The previous two commenters remind me that what PDVSA went through has been replicated to a degree in Corpolec. Idiots replaced engineers. In both institutions the advice of engineers was ignored when maintenance and investment were neglected. Thus the current crisis.
Given what has occurred with PDVSA and Corpolec, one might assume Venezuela didn’t have competent engineers, which meant that there was no alternative to idiots making the decisions. The sad truth is that Venezuela has long produced competent engineers, but Chavismo has either ignored them or cast them aside.
I wonder what canilla sandwiches are.
March 23, 2010 at 11:32 am
who remembers Zarea’s cricri and canilla sanduiches??? (lots of inside info and venezuelanism here!
….sorry PSF! do you homework!!!
Who went to The Pleassure to get him some?….
good times!
BTW anybody researching into hitachi’s warranty conditions for the turbines operations under the spec. levels? another liability on the making.
March 23, 2010 at 10:59 am
This info should be easy to understand to anyone who in the past took Zarea’s class, or for that matter in Frank Kenyery’s, in Mechanical Engineering at the first institution which openly and publicly opposed “El Caudillo” (a.k.a. “Esteban”) I believe only two years after he took over on a speech in one of its auditoriums: the USB. On one hand this was bad since it meant a big cut in government funds, but on the other hand it forced the university to look for funds in private industry projects.
I’m not keeping up to date these days on who’s currently teaching the Energy Conversion series (Turbomaquinas Hidrauilcas, Turbomaquinas Termicas, a.k.a. Conversion the Energia I, II, and III). Zarea and Kenyery were the professors teaching these classes when I went to the USB.