Guri Hydroelectric Power Plant, Orinoco, Venezuela
The Guri hydroelectric power plant is situated 100km upstream of the Caroni River in Necuima Canyon in Orinoco, Venezuela. The power plant has an installed capacity of 10,200MW and is the third largest power plant in the world. Venezuelan power company CVG Electrification del Caroni CA (Edelca) operates and maintains the power plant.
The plant provides around 12,900GW/h of energy to the country. Construction of the power plant was carried out after the government adopted a policy in the 1960s to minimise the amount of energy produced from fossil fuels. The plant contains three high-voltage switchyards running at 800kV, 400kV and 230kV. The switchyards are arranged in a breaker-and-half configuration.
Edelca is currently carrying out a modernisation programme to extend the plant's life by 30 years. As part of the modernisation programme, Andritz Hydro was awarded a €100m contract in 2007. The contract involves supplying five 770MW Francis turbines for powerhouse II of the power plant. Andritz also received a follow-up order to supply and install excitation equipment for the powerhouse II in 2009. The company supplied the first of the Francis turbines, weighing 200t, to the Guri power plant in the third quarter of 2009.
In May 2009, Alstom Hydro received a second contract worth €31m from Edelca to refurbish five 630MW generators of powerhouse II of the power plant. The first contract worth €80m was awarded in 2007 for the refurbishment of four 400MW Francis turbines and generators of powerhouse I of the power plant.
Guri hydroelectric power plant construction
The feasibility studies for constructing the power plant started in 1961. Harza Engineering Co. International carried out both the technical and economic studies. In 1963, a consortium, consisting of Kaiser Engineering and Constructors, Macco International, Tecon International, Merritt Chapman & Scott Overseas, Christian Nielsen and Technical Building Construction, was awarded the contract for the construction of the plant.
Towards the end of 1963, the initial construction work, earthworks and routes of the access roads commenced. In 1964, the Caroni River was diverted to the right side of the bank to enable construction of the plant. The civil works of the first stage of the power plant were completed in 1976, consisting of powerhouse I with ten generators and a capacity of 2,065MW.
The final stage of the construction for the power plant started in 1978. In 1982, four main construction works were taken up, which included the concrete dam (Guri Dam) and powerhouse II, the excavation of the second channel and discharge operation plant of aggregates, earth and rockfill dams left and right.
In 1984, the first unit of powerhouse II was commissioned with ten 630MW generators. The completed Guri power plant was inaugurated in 1986.
HPC Venezuela (VHPC), an affiliate unit of Hitachi Plant Technologies, was awarded the contract for the construction of powerhouse II. Construction work carried out by VHPC included the installation of ten water turbines with a capacity of 730MW and ten auxiliary transformers. In addition, VHPC installed a water treatment system, six elevators and a complete carbon dioxide fire-fighting system among other works.
Hydroelectric power plant technology
Under the modernisation programme of the power plant, a consortium consisting of ABB Venezuela, ABB Canada and ABB Switzerland was awarded a contract to conceive and install the unit control, protection and instrumentation systems for the power plant.
ABB chose to install an industrial video and control (IVC) system and integrated it with a leak detection system to monitor the Guri dam. The IVC system helps in identifying a range of alarm protocols and responds to alarms by starting user-defined responses such as camera functions.
Venezuela power market
Around 73% of the country's energy needs are met by the Guri power plant. In January 2010, however, it became evident that Venezuela had become over-dependent on the power plant to supply its energy needs.
Water levels in the Guri dam have fallen drastically and if they continue to fall, the country is expected to face a power crisis in the next six months. The government will have to suspend the generation of around 5,000MW of power, which will lead to widespread blackouts.
Several measures such as the use of energy saving bulbs and an increase in tariffs for commercial users need to be adopted to prevent an energy crisis occurring in Venezuela. In addition, reducing power demand in shopping malls and government buildings may help.