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    Renewable energyIEE Power Engineer | February/March 2006 23

    To say that Yacyret, Argentinas largesthydroelectric power station, has enduredmixed fortunes since its inception in 1983,would be an understatement. While regardedas one of the worlds most importanthydroelectric projects, the power station has

    been plagued by controversy after controversy.Built jointly by Argentina and Paraguay 1000km north

    of Buenos Aires on a section where the Paran Riverdefines the border between the two countries, the dam was

    designed to harness the hydraulic resources of thepowerful river, which flows on average at 12,000m3/s (fig 1).

    But, because of the low-lying geographic charac-teristics of the area, the dam is not particularly high: itmeasures only 42m at its highest point whereas ChinasThree Gorges dam towers at 185m. This means that boththe length of the dam and the resulting reservoir are, bynecessity, huge. The dam spans 67km and the reservoirssurface area is at present 1220km2, with a length of342km upstream.

    Despite the blunders, corruption and controversy, Argentinas largest hydroelectric powerstation could at last be edging towards completion, as Juan Pablo Conti discovers

    ten billiondollardam

    The

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    But, although already twice as big as the lake that willbe created by the Three Gorges reservoir in China, theoriginal plans for Yacyret were always to extend thereservoirs surface beyond todays 1220km2, up to 1600km2.For myriad reasons, this hasnt happened, so, since thestation started generating electricity in 1994, it has neveroperated at full capacity.

    UNTESTED POWERConstruction at Yacyret began in December 1983. Theproject was partly financed by the World Bank and theInter-American Development Bank with ownership sharedbetween the Argentinean and Paraguayan states, whichadminister the complex through an institution called EBY(Yacyret Binational Entity).

    Plagued by a series of delays and corruption scandals,the last of the 20 Kaplan turbines was turned on in July1998. By then, total costs had rocketed from the $5.3bninitially budgeted to more than $10bn.

    Even worse, the turbines started generating before thejob was actually finished and, today, more funds are stillneeded to complete the project officially. When engineersclosed the floodgates in 1994 they decided that, instead offilling the reservoir to 83m above sea level as originallyspecified in the design, they were going to fill it to only 76mabove sea level (fig 2).

    These seven metres waiting to be raised in the reservoirtranslate into a seven metre water head deficit. So, whilethe dam and turbines were designed to perform with a 21.3mhead, they are only pumping water with a 14.5m head,

    yielding an effective total generation of between 1700MWand 1800MW. Should the water level be raised to the required83m above sea level, the station could yield 3200MW.

    So, why make the decision to effectively under-fill thereservoir? The move was motivated by the urge to get theplant operational, even though the civil work and, someclaim, the environmental studies were far from complete.

    For example, of the 80,000 people needing to be resettled,following the building of the dam, only about 30% wererelocated to the new neighbourhoods purposely built byEBY. And, until the remaining 70% of families are resettledaway from the reservoir, Yacyrets powerhouse willcontinue to operate at only 60% of its installed capacity.

    Oscar Dores, director of FUNDELEC, an independentorganisation monitoring Argentinas power sector, likensthe problems to similar issues encountered when building

    a motorway. When youexpropriate an area ofland to build a motorway,if you leave the housesstanding and dontadvance promptly withthe layout, people willreoccupy those premises,he says. You have to be

    tionsrose

    y out

    aimssince: Allg thearryable

    omesigateoded

    2 IEE Power Engineer | February/March 2006 25

    lands are in Paraguayan territory. Whats more, Paraguayonly receives a minuscule amount of the energy producedby the dam Argentina consumes the vast majority andpays back its partner country for its share.

    Resettlement and output issues aside, ever sinceconstruction began at Yacyret in the 1980s, suspicionswere rising over the publicly financed multi-billion dollarproject being abused by those in charge of it. Come the1990s it was abundantly clear that these suspicions werewell founded.

    Any lingering doubts were banished when the thenPresident of Argentina, Carlos Menem, famously

    described the dam as a monument to corruption. Hislater moves to privatise the station and sell it to former USPresident George Bush Sr were blocked by the ArgentineCongress.

    Over-spending has also been a major issue. While muchof the extra $5bn spend over and above the original $5.3bnbudget stemmed from renegotiating debts with World andInter-American Development banks, the cost of numerousfraud allegations cannot be underestimated. These includeanything from excessive rates paid to expropriate lands tothe renewal in April 2003 of an insurance policy withBritish insurer Heath, which according to an internalauditor was contracted without a public bidding processand overpriced to the tune of $1.5m per year. And this isjust the beginning.

    In 2002 EBY renewed a contract worth $42m with CIDY,the engineering and construction consortium supervisingYacyret, but Argentine experts later denounced theaward, saying the job could have been carried out moreefficiently by in-house personnel. A legal bid to recover$17m, unduly paid to Italian generator supplier Ansaldois underway, and, incredibly, the dams main constructorEryday claims it is owed $1.5bn in a dispute that startedover the price paid for the mortadella sausage sandwichesgiven to workers.

    Looking beyond corruption, however, the key problemfor anyone with a financial interest in Yacyret is the factthat operating at 60% of full capacity obviously translatesinto poorer production figures than those originallyanticipated. While Yacyret should be contributing to

    Renewable energy

    Building Yacyret used 3,500,000m3 of concrete. Thisfigure is four times that used for the Channel Tunnel, butonly around one seventh of the incredible 26,400,000m3

    being used to build Chinas Three Gorges Dam.

    Each of the 20 Kaplan turbines sitting inthe 808m-long X 80m-wide X 70m-highpowerhouse have a maximum capacity of160MW and rotate at 71.4rpm. They havea 9.5m diameter and weigh 278t. Thegenerators have a maximum power of172.5MVA, operate at 50Hz/13.2kV andweigh 600t (rotor diameter is 16m). Thecomplex works 24 hours a day, with anaverage of 8000m3 of water passingthrough the turbines every second.

    Voith Hydro, Germany, manufactured13 turbines, with the other seven built byArgentinas Impsa and Cometarsa. GECanada and Voith were responsible for themechanical design, with the latter also incharge of the hydraulic design for theadjustable blades typical of Kaplanturbines. The generators were supplied bySiemens, Ansaldo of Italy, Mitsubishi,Hitachi and Toshiba, while the turbine-generators were assembled on-site by

    Impreglio, CIE, Sade and Iglys.Yacyrets powerhouse is located on

    the Yacyret Island, next to the mainbranch of the river. Two spillways, one onthe main branch and the other one on theAa Cu branch, have a capacity of95,000m3/s and although this mightseem a massive figure, consider that in1905 the Paran registered a record53,000 m3/s flow.

    A navigation lock was also built torespond to the stated goal of improvingnavigation of the river, which used to beextremely difficult in a section now fullycovered by the waters. The lock is 270mlong and 27m wide, and allows a bargetrain to negotiate the 23m water leveldifference in 45 minutes. Two fish liftswere additionally installed to help speciesmigrating upstream, which operate underthe permanent supervision of a team ofbiologists (see image).

    Yacyrets electricity is fed intoArgentinas national grid via three 500kVlines running from the back of the damto the nearby Rincn de Santa Marasubstation. Another 220kV line travels tothe opposite side of the river to reachthe Ayolas substation, linked withParaguays grid.

    Hardware matters

    ARG E NTI NA

    PAR AG UAY

    Powerhouse

    SanIgnacio

    SantaAna

    Blocked stream

    Earth damreservoir

    Bridge

    Substation(Par)

    Yacyreta Island

    Navigation lock ARG E NTI NA

    PAR AG UAYAa Cuaspillway

    6

    1

    12

    ParanaRiver

    Main spillwayopposition,Interesti

    from Paragufurther, its e

    IEE Power Engineer | February/March 2006

    Posadas (Argentina) andEncarnacin (Paraguay)quick. The complicawith Yacyret a

    because of the extremely long time its taken to carrthe project.

    Dores goes on to highlight the inevitable legal clsurrounding resettlement from the people who have been occupying the coast of the reservoir, but addsthese problems could be solved. It just requires havinmoney, management skills and political strength to cout the new plan, because there is consider

    he adds.ngly, Dores says a lot of this opposition cay and not Argentina, but when you investasy to see why. For starters, most of the flo

    4

    Fig1: Yacyret is located400km downstream from

    Substation (Arg)

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    But, although already twice as big as the lake that willbe created by the Three Gorges reservoir in China, theoriginal plans for Yacyret were always to extend thereservoirs surface beyond todays 1220km2, up to 1600km2.For myriad reasons, this hasnt happened, so, since thestation started generating electricity in 1994, it has neveroperated at full capacity.

    UNTESTED POWERConstruction at Yacyret began in December 1983. Theproject was partly financed by the World Bank and theInter-American Development Bank with ownership sharedbetween the Argentinean and Paraguayan states, whichadminister the complex through an institution called EBY(Yacyret Binational Entity).

    Plagued by a series of delays and corruption scandals,the last of the 20 Kaplan turbines was turned on in July1998. By then, total costs had rocketed from the $5.3bninitially budgeted to more than $10bn.

    Even worse, the turbines started generating before thejob was actually finished and, today, more funds are stillneeded to complete the project officially. When engineersclosed the floodgates in 1994 they decided that, instead offilling the reservoir to 83m above sea level as originallyspecified in the design, they were going to fill it to only 76mabove sea level (fig 2).

    These seven metres waiting to be raised in the reservoirtranslate into a seven metre water head deficit. So, whilethe dam and turbines were designed to perform with a 21.3mhead, they are only pumping water with a 14.5m head,

    yielding an effective total generation of between 1700MWand 1800MW. Should the water level be raised to the required83m above sea level, the station could yield 3200MW.

    So, why make the decision to effectively under-fill thereservoir? The move was motivated by the urge to get theplant operational, even though the civil work and, someclaim, the environmental studies were far from complete.

    For example, of the 80,000 people needing to be resettled,following the building of the dam, only about 30% wererelocated to the new neighbourhoods purposely built byEBY. And, until the remaining 70% of families are resettledaway from the reservoir, Yacyrets powerhouse willcontinue to operate at only 60% of its installed capacity.

    Oscar Dores, director of FUNDELEC, an independentorganisation monitoring Argentinas power sector, likensthe problems to similar issues encountered when building

    a motorway. When youexpropriate an area ofland to build a motorway,if you leave the housesstanding and dontadvance promptly withthe layout, people willreoccupy those premises,he says. You have to bequick. The complicationswith Yacyret arose

    because of the extremely long time its taken to carry outthe project.

    Dores goes on to highlight the inevitable legal claimssurrounding resettlement from the people who have sincebeen occupying the coast of the reservoir, but adds: Allthese problems could be solved. It just requires having themoney, management skills and political strength to carryout the new plan, because there is considerableopposition, he adds.

    Interestingly, Dores says a lot of this opposition comesfrom Paraguay and not Argentina, but when you investigatefurther, its easy to see why. For starters, most of the flooded

    24 IEE Power Engineer | February/March 2006

    lands only rby thepays b

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    Renewable energy

    Buildfiguronly bein

    powerhouse have a maximum capacity of160MW and rotate at 71.4rpm. They havea 9.5m diameter and weigh 278t. Thegenerators have a maximum power of172.5MVA, operate at 50Hz/13.2kV andweigh 600t (rotor diameter is 16m). Thecomplex works 24 hours a day, with anaverage of 8000m3 of water passingthrough the turbines every second.

    Voith Hydro, Germany, manufactured13 turbines, with the other seven built byArgentinas Impsa and Cometarsa. GECanada and Voith were responsible for themechanical design, with the latter also incharge of the hydraulic design for theadjustable blades typical of Kaplanturbines. The generators were supplied bySiemens, Ansaldo of Italy, Mitsubishi,Hitachi and Toshiba, while the turbine-generators were assembled on-site by

    the Yacyret Island, next to the mainbranch of the river. Two spillways, one onthe main branch and the other one on thAa Cu branch, have a capacity o95,000m3/s and although this mighseem a massive figure, consider that in1905 the Paran registered a record53,000 m3/s flow.

    A navigation lock was also built torespond to the stated goal of improvinnavigation of the river, which used to bextremely difficult in a section now fullcovered by the waters. The lock is 270mlong and 27m wide, and allows a bargtrain to negotiate the 23m water levedifference in 45 minutes. Two fish liftwere additionally installed to help speciemigrating upstream, which operate undethe permanent supervision of a team obiologists (see image).

    Fig1: Yacyret is located400km downstream fromPosadas (Argentina) andEncarnacin (Paraguay)

    ARG E NTI NA

    PAR AG UAY

    Powerhouse

    SanIgnacio

    SantaAna

    Blocked stream

    Earth damreservoir

    Bridge

    Substation(Par)

    Substation (Arg)

    Yacyreta Island

    Navigation lock ARG E NTI NA

    PAR AG UAYAa Cuaspillway

    6

    1

    12

    ParanaRiver

    Main spillwaysonnel. A legal bid to recovern generator supplier Ansaldo

    ly, the dams main constructor1.5bn in a dispute that started

    ortadella sausage sandwiches

    tion, however, the key probleml interest in Yacyret is the factll capacity obviously translatesigures than those originally should be contributing to

    eft

    onument to corruption. His station and sell it to former US

    were blocked by the Argentine

    been a major issue. While mucher and above the original $5.3bnegotiating debts with World andnt banks, the cost of numerous underestimated. These includetes paid to expropriate lands to

    3 of an insurance policy withich according to an internalithout a public bidding process

    e of $1.5m per year. And this is

    contract worth $42m with CIDY,uction consortium supervising experts later denounced theld have been carried out moree job cou

    -house perid to Italia, incredib is owed $id for the m.nd corrup financia

    60% of fuduction fle Yacyret

    . located onettlement and output issues aside, ever sinceuction began at Yacyret in the 1980s, suspicionsising over the publicly financed multi-billion dollart being abused by those in charge of it. Come thet was abundantly clear that these suspicions wereunded. lingering doubts were banished when the thenent of Argentina, Carlos Menem, famously

    Eryday claims itover the price pagiven to workers

    Looking beyofor anyone with athat operating atinto poorer proanticipated. Whi

    Each of the 20 Kaplan turbines sitting inthe 808m-long X 80m-wide X 70m-high

    Impreglio, CIE, Sade and IglysYacyrets powerhouse is

    Hardware mattersare in Paraguayan territory. Whats more, Paraguayeceives a minuscule amount of the energy produced dam Argentina consumes the vast majority andack its partner country for its share.

    anything from exthe renewal in ABritish insurer Hauditor was conand overpriced tjust the beginnin

    In 2002 EBY rethe engineering aYacyret, but Aaward, saying thefficiently by in$17m, unduly pais underway, and

    ing Yacyret used 3,500,000m3 of concrete. Thise is four times that used for the Channel Tunnel, butaround one seventh of the incredible 26,400,000m3

    g used to build Chinas Three Gorges Dam.described the dam as later moves to privatisePresident George BushCongress.

    Over-spending has aof the extra $5bn spendbudget stemmed fromInter-American Develofraud allegations cannoIEE Power Engineer | February/March 2006 25

    gey

    elssrf

    Yacyrets electricity is fed intoArgentinas national grid via three 500kVlines running from the back of the damto the nearby Rincn de Santa Marasubstation. Another 220kV line travels tothe opposite side of the river to reachthe Ayolas substation, linked withParaguays grid.

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    the Argentinean and Paraguayan grids with up to 20TWh perannum, its record production year was 2002, when favourablehydraulic conditions in the Paran Basin helped it accumulate12.33TWh.

    So, with this massive shortfall in mind, will we seeYacyret operating at full pelt in the near future? With a bit ofluck, yes.

    Last November, Argentinas President Nestor Kirchnerannounced that a bank had been contracted to administer$563m of government cash to finish Yacyret. The work willtake another four years to complete and estimations suggestthat 1167 different building works will be needed before thereservoir can be topped up to get the station running at fullspeed.

    The water level is set to be gradually raised from itscurrent 76m above sea level to 78m this year, 80m in 2007. Andfinally, more than 15 years later than originally scheduled, themagic 83m will be reached in 2009.

    partly-privatised power infrastructure. Expansion hadcome to an abrupt halt in 2002 when the government in abid to stabilise the country decreed all utility prices wouldbe frozen until further notice.

    As FUNDELECs Oscar Dores points out, the last timeArgentina saw a new power station installed was inOctober 2000, with the 800MW, combined-cycle gasturbine San Nicolas plant. Since then, not a single MWhas been installed although from the 2001/02 crisis untilthe present day, our electricity demand has increased25%, he says.

    Today, Argentinas national power generation capacitystands at around 22,000MW. The last peak in consumption,registered on 22 November 2005 and breaking the all-timenational record, was measured at 16,000MW.

    NEARING CAPACITYIf you take into account that you will need some 20% of

    26 But its not just about boosting the hydro figures. In asimilar vein to the rest of the developed world, Argentina isfacing an energy shortage.

    After four years of a terrible recession that led to the 2001economic, social and political debacle, Argentinas economyis picking up. The country has now enjoyed more than threeyears of solid growth, with 2005 registering nearly 10%.Unfortunately, the welcome growth has brought its own set ofproblems.

    As early as 2004, alarm bells started to ring over the strainthat sustained economic growth would put on the nations

    also been agreed with Brazil, whereby Argentina will beable to import 750MW during its annual peak demandperiod in February-March.

    So will these additional projects see Argentina lookingforward to a secure and bright future? Highlighting growthin the nations thermal facilities in the late 1990, Dores isoptimistic.

    Four thousand megawatts [of thermal generation] wereinstalled in five years through the construction of a seriesof new turbo gas stations, he says. We had a boom in thedeployment of state-of-the-art combined cycle equipment.This equipment was designed to take advantage of our gasresources and improve the calorific efficiency of thermalstations. Today, Argentina has one of the worlds mostmodern thermal generation infrastructures.

    And, if Yacyret does at long last fulfil its originalexpectations, bringing an end to the monumentalcontroversy, then perhaps the nations fortunes really willbe looking brighter.

    IEE Power Engineer | February/March 2006

    Fig 2: Together Yacyrets two spillways can receive 95,000m3/s of water,although the reservoirs water level has yet to be raised another 7mClearly, the Argentine government is keen to complete thedam, and if we check out the figures its easy to see why.During Yacyrets vintage year of 2002, its 12.33TWhproduction equalled 33% of the electricity generated by all ofthe countrys hydro stations, and 16% of total demand onArgentinas grid. Should the plant have been operating at itsfull capacity, the latter figure would haveswollen to an impressive 25% of allelectricity consumed by the country.

    your total generation infrastructure for maintenanceprogrammes, you can see the supply and demand levels aregetting dangerously close, says Dores. This indicates wewill undoubtedly experience a supply deficit for the nexttwo years.

    Doress prediction takes into account the fact thatgovernment plans to launch new powerstations will not come to fruition until2007, at the earliest. However, after thispoint in time, the future is lookingbrighter.

    Yacyrets untapped potential shouldbecome available in early 2009. Justabout then, Argentinas third nuclearpower station the $3bn, 600MW

    Atucha II, whose construction was put on hold in the 1990s could be finalised.

    Whats more, two new thermal facilities are also set tobe built during the 2007/08 period: a 1080MW open-cyclestation and a 1600MW combined-cycle plant. And a deal has