IWP&DC presents details on 10 hydro power and dam construction projects recently completed or under development in South America
La Confluencia, Chile
The 158MW La Confluencia hydro power project in Chile is being developed by electricity operating company Tinguiririca Energia. The company is comprised of Australian utility Pacific Hydro and SN Power, a Norwegian venture of utility Statkraft and the Norfund Power Invest AS Fund. Hochtief-Tecsa, a joint venture formed between German company Hochtief’s Chilean subsidiary and the Chilean Tecsa SA, is the main contractor for the project.
Estimated at a total cost of US$350M, La Confluencia is scheduled for completion in 2010. It is located in the foothills of the Chilean Andes in the Tinguiririca Valley, about 140km from Santiago at an elevation of 1430m.
The run-of-river scheme is located on the Tinguiririca, Portillo and Azufre rivers and consists of intakes and conveyance systems on two branches. The Portillo branch comprises a low weir and spillway on the Portillo river at 1465m asl. Water will pass through a desander and short open channel before entering an 11km low pressure tunnel that runs to the surge chamber above the powerhouse at the Azufre and Tinguiririca rivers.
The Tinguiririca branch consists of a low diversion weir and spillway across the Tinguiririca river at 1450m asl that will divert partial flows through a desander and short open channel to a regulation pondage of 1.2Mm3 of live storage capacity.
Water from this will be taken via a 9.3km low pressure tunnel that joins the surge chamber above the powerhouse, which will contain two 77.5MW Voith Hydro turbines and generators. A 16km long transmission line will connect the project to La Higuera switchyard.
The Tinguiririca and Portillo branch tunnels terminate at a concrete lined vertical shaft, which drops to the open air La Confluencia power house via a concrete and steel lined high pressure tunnel. This water will then be discharged directly into the conveyance system for the La Higuera hydro power project for additional power generation.
La Confluencia is under construction upstream of the La Higuera project, which is also being developed by Tinguiririca Energia. The two projects are being developed entirely separately from one another but are being designed to operate in cascade. They will also be able to operate independently in case either plant needs to shut down. It is estimated that both projects will generate approximately 1400GWh/yr.
Water inflows at La Confluencia are primarily determined by snow melt. This makes the project’s hydrology quite different from that of rain-fed hydro schemes. During the dry season it will be supplied by snow melt and during the wet season from rainfall. Therefore it is expected that La Confluencia will be available at full load during the dry season when the hydrology in the system is below average and the cost of generation tends to be higher.
The Chilean national energy authority, Comision Nacional de Energia, is reported to have been very supportive of the project which is estimated to produce 638GWh/yr upon completion.
Sao Salvador, Brazil
The 241MW Sao Salvador project in northern Brazil was commissioned in February 2009. It is located on the Tocantins river between the states of Tocantins and Goais. Construction was completed within 32 months. The plant has guaranteed power of 148.5MW which has been sold by auction for US$2.6B for 30 years starting from 2011.
The project was developed by GDF Suez’s local subsidiary Tractebel Energia, which was responsible for project construction and installation of the transmission lines to connect the generating plant to the electricity grid system. The company was awarded the concession to build the project in 2001 and a total investment of US$395M was required for the scheme. It was also the first hydro project to be financed under Brazil’s new growth acceleration programme (PAC) from which it received US$277M from the Brazilian development bank.
Furthermore the project helped to create 10,000 jobs within the region. Over US$31M was also invested in 35 different social and environmental programmes. These relate to resettlement, environmental education and conservation of local flora and fauna. In recognition of this the project was awarded the declaration of legal and socio-environmental conformity from Bureau Veritas (BVQI). BVQI is an independent certification body which operates on a worldwide scale.
Chairman and CEO of GDF Suez, Gerard Mestrallet, said that Sao Salvador is symbolic of the company’s industrial development in Brazil. It is also leading a joint venture which will build the 1087MW Estreito plant on the Tocantins river between the states of Tocantins and Maranhao.
Manuel Piar (formerly Tocoma), Venezuela
The Manuel Piar hydro power project is the last scheme to be developed in the Bajo Caroni hydro power complex on the lower Caroni river watershed in Venezuela. Three dams (Guri, Carauachi and Macagua) are already in operation. Upon completion the fourth project, Manuel Piar, is expected to add an estimated 2160MW of power to the national grid. It will produce an average of 12,100GWh/yr, which is equal to the entire electrical consumption of Caracas in 2004, or 13% of Venezuela’s total generation demand. Together, the four plants will provide 70% of the country’s electricity.
Manuel Piar is being developed by the state-owned utility CVG-Electrificacio del Caroni (Edelca). Initial river diversion took place in 2002. The main components of the project include a 65m high and 360m long CFRD dam, with a reservoir capacity of 1770×106 m3. The existence of the Guri reservoir upstream, with its large potential for regulating the flow of the Caroni river, has enabled the size of the Manuel Piar reservoir to be considerably smaller than would have been necessary for a hydro project of a similar size.
IMPSA was awarded the turbine and generator contract for the project in 2008. The powerhouse will have ten Kaplan units, each with 216MW of rated power, 235MW of maximum capacity, a rated head of 34.65m and speed of 90rpm. The ten generators are three-phase, vertical shaft, salient-pole synchronous machines. They each have a capacity of 237MVA, a voltage of 13.8kV and a frequency of 60Hz. The stator inner diameter is 12.65m with a core length of 2.05m. The rotor consists of a welded spider and a rotor rim made up of stacked segments for asymmetric radial ventilation, with the rotor generating pressure for machine cooling.
The Inter-American Development Bank (IDB) has given two loans to the project. A US$750M loan was awarded in 2005, and a second of US$800M in 2009. The latter is to help complete construction of the project and ensure financial stability of the scheme. The loan has a six-year grace period and an adjustable interest rate.
The total project cost for Manuel Piar was estimated at US$3B in 2005 but since project approval this has increased significantly due to the impact of inflation and its impact on the local currency. According to the Central Bank of Venezuela, cumulative inflation from 31 December 2003-8 was 105%.
Based on December 2008 prices the project cost is now equivalent to US$4.3B – a 40% increase based on December 2003 prices. The IADB said that adjusting physical works to keep within the original budget wasn’t feasible, hence why it provided further funding for the scheme.
Manuel Piar is expected to come on stream in stages between July 2012 and March 2014.
The project was originally called Tocoma but its name was changed by a presidential order in April 2006.
Madeira complex, Brazil
The 6.45GW Madeira hydro power scheme in Brazil comprises the 3300MW Jirau and 3150MW Santo Antonio projects on the Madeira river close to the Bolivian border. It is the biggest hydro scheme under development in South America.
The 30-year concession to build Jirau was granted to Energia Sustentavel do Brazil which is made up of GDF Suez (50.1%); Brazilian electric utilities Eletrosul (20%), Chesf (20%); and construction group Camargo Correa (9.9%). Construction started in December 2008 and the first of 44 turbines are due to become operational in March 2012.
In July 2009 the Brazilian National Development Bank (BNDES) and a pool of five private banks agreed to provide US$3.61B in debt funding for project construction. This finance facility will equate to 68.5% of the total investment cost of the project. The private banks are Banco do Brasil, Caixa Economica Federal, Banco Nordeste do Brasil, Itau-Unibanco and Bradesco. The project is part of the Brazilian government’s growth acceleration programme (PAC).
The second component of the Madeira complex, the Santo Antonio project, is being developed by the consortium Santo Antonio Energia. This comprises power companies Furnas and Cemig, construction firms Odebrecht and Andrade Gutierrez, plus banks Santander and Banif. Construction will be carried out by a wide ranging consortium called Consorcio Construtor Santo Antonio (CCSA) which comprises Odebrecht, Andrade Gutierrez, alstom-hydro Energia Brasil, Siemens, Voith Hydro and Andritz Hydro amongst others. BNDES is to provide a US$2.55B loan for the project.
Operation of the project’s first bulb turbines will begin gradually from May 2012. Full commercial service of all 44×71.6MW units is expected by November 2015. The project will have an installed capacity of 3150MW – equivalent to 4% of all the energy generated in Brazil in 2007.
The bulb turbines will take advantage of the rapid flow on the river Madeira – 4000m3/sec during the dry season and 45,000m3/sec during the rainy season. This means that compared with the 271km2 area the whole development will occupy, the plant has a relatively small capacity reservoir. Some 164km2 will be covered by natural flooding, which will result in an increase of the flooded area by only 107km2, corresponding to an area/installed power relation of 0.086km2/MW.
In August 2009 ABB secured a contract worth more than US$540M to build the 600kV connection from the river Madeira area where the Santo Antonio and Jirau projects are under construction. The company will supply a pair of 3150MW HVDC converter stations plus an 8000MW HVDC back-to-back station to transmit power over the long distance. The transmission project is to be completed by 2012.
In December 2009 Areva T&D was awarded a US$400M contract for work on the transmission link. Power from the project will be transmitted through two HVDC bipoles from the northwest to the southeast of Brazil, allowing the integration to the National Interconnected System and the utilisation of energy throughout Brazil.
The Misicuni project will increase the supply of water for domestic use and irrigation to the Cochabamba Valley while generating electricity for Bolivia’s National Interconnected System. The Cochabamba region has been increasingly suffering from a scarcity of water both for human consumption and for agriculture, and Bolivia needs to expand its electricity generation capacity to meet the growing demand.
The whole project comprises the construction of a 120m high concrete faced rockfill dam (CFRD), a 20km tunnel for water diversion (finalized in 2005 with the financial support from the Government of Italy), a pressurized piping system (from 3700 to 2700m asl) that conveys a controlled water flow from the tunnel to the power plant to be built in the Cochabamba Valley. The dam construction contract (US$85M) has been awarded to an Italian-led consortium Consorcio Hidroelectrico Misicunand (51% Grandi Lavori Fincosit), and the financing is in place. The works for the hydroelectric power plant, including complementary investments such as a substation and a transmission line, estimated at about US$114.1M, will be financed with a loan from the Inter-American Development Bank (IDB).
A total of $101M in IDB loans will be used to build the hydroelectric component of the project, including electric power transmission and related works, which will contribute up to 80MW of power to the national grid. Construction of the dam on the Misicuni River, which began in June 2009, is expected to cost $85M and is being financed by the Government of Italy, the Prefecture of Cochabamba, Bolivia’s National Treasury, and the Andean Development Corporation.
An additional $5M in IDB financing will be used to finance the Misicuni Watershed Environmental Management Project. This project will supplement and strengthen measures to mitigate the indirect impacts of the Misicuni Project on the environment and population in the main dam’s watershed.
Specifically, these funds will be used to reduce susceptibility to erosion, enhance water management, and protect priority habitats in the areas of the watershed most exposed to such risks. They will also be used to promote soil and water conservation measures and sustainable, income-generating alternatives to subsistence farming within the communities resettled due to construction of the dam.
The IDB financed project will also help the affected communities to develop agricultural activities that will compensate for productive losses associated with the construction of the main dam.
An Astaldi-led joint venture will build the 90MW Huanza hydroelectric power plant in Peru. The contract includes execution of civil works, construction of a roller compacted concrete (RCC) dam (volume of 30,000m3), a 10km tunnel, powerhouse and switchyard. Work is scheduled for completion in 29 months.
The JV comprising Astaldi (60%) and Peruvian construction company Graña y Montero (40%) was awarded the US$116M contract by mining firm Minera Buenaventura .
The project has been in development for many years, with construction on the project originally scheduled to start in July 2001 and operations were scheduled for October 2004. The project was reportedly delayed however due to government restrictions favouring natural gas power ventures.
Located in a dramatic setting in the Andes Mountains, the Chacayes hydro project will be the first phase of Australian firm Pacific Hydro’s new project development in the Cachapoal Valley. The delivery of this run of river hydro project in October 2011 is critical to solving the supply of capacity into the Chilean energy grid and the reduced reliance on energy from fossil fuels.
Chacayes will generate 558GWh per annum of renewable energy for Chile’s power market, which is enough electricity to supply twice the demand of the city of Rancagua and will abate approximately 340,000 tonnes per annum of greenhouse gas pollution.
Chacayes was given environmental approval by COREMA VI Region in July 2008. A few months later, in October 2008, Chilean President Michelle Bachellet unveiled the first stone to mark the commencement of advance works construction for the project.
In October 2008 the consortium Astaldi-Fe Grande, formed by the Italian construction company Astaldi and the Chilean Fe Grande, was awarded the contract for the construction of the hydro station in an Engineering Procurement and Construction (EPC) agreement. In May 2009 Pacific Hydro consolidated a joint venture with Astaldi by which the Italian company entered in the property of Chacayes with a 27% interest. By this strategic joint venture each party looks to contribute their experience and knowledge, sharing the risks and the administration so the project can be finished successfully in time.
The success of the project is closely linked to the welfare of the communities that surround the sites which is why the developers created the community development fund, ‘Creciendo Juntos’ (Growing Together) in the Cachapoal Valley. This initiative aims to improve the quality of life of the communities during construction and operation of the power stations. Applications to the Community Funds are developed and submitted by the communities themselves for projects that improve the health, environment, education and welfare of their communities.
As important as the Community Funds are for improving the infrastructure and living environment of these communities, the greatest economic benefit will come from employment. At the peak of construction of the Chacayes project around 1200 direct and 3000 indirect jobs will be created in and around the valley.
Porce III is a hydro power project located in the Department of Antioquia, Colombia, on the western side of the Cordillera Central. Situated 47km northeast of the city of Medellín, capital of Antioquia, it is shared by the municipalities of Amalfi, Guadalupe, Gómez Plata and Anorí.
The 844MW project is scheduled for completion this year. The project, on the Porce River, includes a 155m high CFRD dam with a crest length of 426m. Ingetec, in joint venture with klohn-crippen Co. Ltd, undertook the detailed designs of the Porce III Dam for Empresas Publicas de Medellin – E.S.P. (Medellin Public Utilities Company).
The dam will have a chute located in the left abutment with a discharge capacity of 10,850m³/sec, controlled by four radial gates and a flip bucket for energy dissipation. The project will also feature a diversion tunnel, vertical shaft and headrace tunnels, tailrace tunnel, and an underground powerhouse.
Financing for the project came from the Japan Bank for International Cooperation (up to $200M) and the Inter-American Development Bank, which also provided $200M. Turbines for the project are supplied by Impsa Hydro, whose scope of supply included four 211MW turbines with their respective spherical valves, speed governors and draft tube gates; and hydro mechanical components like intake gates, radial and outlet sliding gates, trashrake, steel lining, embedded parts, penstocks, and draft tube’s steel lining.
Technical characteristics of the project, as indicated by Impsa Hydro, are as follows:
• Turbines: 4 x 211MW Francis; rated head – 322m; rated speed 360rpm.
• Governors: Electro-hydraulic with PID control.
• Valves: Spherical; 2,500mm diameter; design pressure 374mca; maximum flow 65.30m3/sec.
• Gates: gates for the inlet tunnel are 6462mm wide and 3400mm high; radial gate is 2471mm wide and 5000m high; outlet sliding gates are 3471mm wide and 4200mm high.
• Penstocks: consist of a draft tube with three bifurcators that form four branch lines. The initial 6100mm diameter narrows down to 3100mm for connection to the speherical valve.
Baguari hydro power plant, located on the Doce River in the state of Minas Gerais, Brazil, was inaugurated in October 2009. It is expected to begin power supply early this year.
The project will supply power to the Brazilian grid through four bulb-type generators. The plant will have an installed capacity of 140MW and its net capacity will be 80.2MW/h, sufficient to supply power to 450,000 people. The power will be distributed through the National Interconnected System.
The plant is being developed by UHE Baguari Consortium, which is composed of Neoenergia (51%), Cemig Generation and Transmission (34%) and Furnas (15%). The project required a $300M investment, about 70% of which will be financed by Brazil’s National Bank of Economic and Social Development. It is expected to be completed by April 2010.
The reservoir of the project covers an area of 16km² and includes the regions of Sobrália, Fernandes Tourinho and Alpercata on the right shore and Governador Valadares and Periquito on the left shore. It spreads 22km into Rio Doce.
The plant is being developed by the Consorcio Construtor Baguari consortium, which is led by construction company Odebrecht and includes Voith Hydro and Engevix. Civil construction work is being handled by Odebrecht, while Voith Hydro supplied the complete electro-mechanical equipment for the project, including four bulb turbines that were completely manufactured in Brazil. The first turbine was commissioned in September 2009, three months ahead of schedule. The fourth machine is expected to become operational in March 2010. The 35MW bulb turbines have runner diameters of 5.1m and include generators, control valves, SCADA automation and excitation systems.
Generated electricity will be transmitted by a 230kV substation and related network of 17 towers along 2.9km. The plant’s transmission system will include the Baguari-Governador Valadares line and the Baguari Mesquita line. The company must invest $13.5M for installing transmission infrastructure. The consortium has already pre-sold 77MW/h per annum to about 30 distributors.
Baguari is the first hydro project under the national Program for the Acceleration of Growth (PAC). PAC was unveiled in 2007 and is intended to achieve a sustainable GDP of 5%. It involves the country investing BRL$500bn in infrastructure development, including roads, airports, ports, power projects, houses, water and sewage systems.
The Baguari project was approved by ANEEL, the Brazilian electricity regulatory agency, in 2002. The previous environmental licence was received in 2004 and power bidding began at the end of 2005. The installation licence for the project was granted in 2006 and construction began in May 2007.
The environmental licence was awarded by the State Environmental Policy after the implementation of the Environmental Control Plan. The plan includes 38 programmes. The consortium is also building a fish ladder to facilitate transposition of the barrage.
The consortium is committed to developing a 34-acre reserve and 170ha of ecological corridors at the site.
The project will create 3400 direct and indirect jobs in the region. Residents of low-lying areas that will be flooded because of the project have been relocated to 70 new homes, which were built by the company in Periquito.
Under the social and economic compensation programme, the company has started several infrastructure projects such as the construction of bridges, culverts, wells and a power distribution network.
Coca-Coda Sinclair, Ecuador
The 1500MW Coca-Codo Sinclair project will be Ecuador’s largest hydroelectric scheme once complete. Expected to cost US$2B, the project will include construction of a 55m high CFRD dam and powerhouse on the Coca River and 24km of tunnelling work.
Back in October last year, the government of Ecuador awarded Chinese firm Sinohydro Corporation a contract to build the project in the Amazon province of Napo.
The project is located in the Napo (El Chaco Canton) and Sucumbios (Gonzalo Pizarro Canton) Provinces. Intake works are located downstream of the Quijos and Salado Rivers confluence, while the powerhouse is located at the ‘Codo Sinclair’.
The project’s intake works are made up of two (127m and 151m) concrete spillways for river closure, trash racks, sand traps, sluice gates, and tunnel connection siphon. The concrete-lined power tunnel is 24.8km long, with diameter of 8.7m. Other important features of the project include:
• Penstocks: two concrete pressure conduits from the compensating reservoir to the powerhouse, steel-lined in its final section 1400m long, diameter 5.8m and 5.2m, respectively.
• Powerhouse: 24×39.5x192m to house eight turbine generating groups of 187MW each.
• Transformers cavern: 14x29x192m to house 24 single-phase transformers of 68.3MVA each.