The hydrodynamic power is the result of the transformation of the potential energy of water, that is, a column or height difference of water that moves a primary machine that generates mechanical energy. The mechanical energy later is transformed in electricity, thanks to the use of a generator.
Main components of the hydroelectric plants
A large dam to store water, provide a constant flow of water and accumulate potential energy in the form of hydraulic load. A large capacity of the dam gives reliability to the hydroelectric plant with a guarantee of a constant flow of water to the turbines.
An abduction which is a hydraulic system (in most cases a gallery and a pressure line) responsible for transporting the water to the turbine. The water acquires velocity by two means: height difference and cross-section reduction. The abduction reduces the cross section of the flow increasing the velocity of the flow increasing the kinetic energy of the water.
A machine house where the turbine (primary machine) is housed, and it transforms the energy of water into mechanical energy, then the energy is transferred to the generator (slave machine) to produce electrical energy.
The suction is a hydraulic system that restores the water to its natural course.
The hydraulic plants are usually very expensive and require for implementation long time horizons, but its operating costs are significantly lower than other forms of generating electricity; this mainly because the cost of "fuel" used (water) is zero.
Origins:
The first plant or hydroelectric power plant that produced electricity for public consumption settled in England (1880). However, the energy of moving water already used to turn waterwheels that powered simple machines like a windmill.
Improvements in hydraulic turbines and generators made the central improve their performance, which was essential to meet growing electricity demand that emerged in the early twentieth century.
The first central importance (in size and performance) was built in 1895, in Niagara Falls, United States of America.
Classification of the hydroelectric plants:
■ Large plants with a capacity of 5MW power.
■ Small plants with a capacity greater than 1 MW but less than 5MW power.
■ Mini power plants with a capacity of 100 KW power but less than 1 MW.
■ Micropower plants are those with a capacity greater than 1.5 kW and less than 100 KW power.
■ Hydro chargers, whose power is less than 1.5kW and generate electricity in direct current (to charge batteries).
Advantages of the hydrodynamic power:
■ High quality of useful energy and low operating and maintenance costs
■ Plants have almost no environmental pollution
■ Dams help prevent floods and regulation of water flow for other uses, as irrigation (University of Minnesota, 2014).
Disadvantages of the hydrodynamic power:
■ The erection of the reservoir destroy the natural landscape-altering the natural species o in the area.
Facts of the hydropower
Hydropower is the first renewable source in the world. At present, the installed capacity exceeds 1,000 GW and production in 2014 reached 1,437 TWh, which accounted for 14% of world production of electricity according to data International Energy Agency (IEA). Also, according to the IEA previsions, hydropower will continue to grow at a significant pace to double its current output and exceed 2,000 GW of installed capacity in 2050 (National Geographic, 2015).
The Hydropower triples the installed wind energy plants with 350 GW as the second energy source. The contributions of this technology in recent years have generated more electricity than all other renewable energies together. And the development potential of this technology is enormous, especially in Africa, Asia, and Latin America. The roadmap of the IEA expects global installed capacity to almost 2,000 GW in 2050, with worldwide production exceeding 7,000 TWh of electricity
Most of the growth in a hydroelectric generation will come from large projects in emerging and developing economies. In these countries, large and small hydropower projects can improve access to modern energy services and alleviate poverty in many regions of the planet that still light or drinking water has not arrived.
Most important hydroelectric plants of the world:
a. Hydroelectric power station of the Three Gorges. 22,500 MW. China
Chinese hydroelectric Three Gorges has an installed capacity of 22,500 MW. It is located in Yichang, Hubei Province, and is the largest in the world. It is a conventional reservoir hydroelectric facility that uses water from the Yangtze River, being owned by China Three Gorges Corporation through its subsidiary China Yangtze Power, which also operates the plant (Power Technology, 2013).
The construction of the project required an investment of 18,000 million euros. This colossal work of engineering was initiated in 1993 and was completed in 2012. The dam is 181 meters high and 2,335 meters long; it was carried out as part of the project of the Three Gorges, together with the power plant consisting of 32 700 MW turbines, and two generating units of 50 MW. At present, the annual energy production of the plant just set the world record in 2014 with 98.8 TWh, allowing supply electricity to nine provinces and two cities, including Shanghai.
b. Itaipu Hydroelectric Power Plant. 14,000 MW. Paraguay-Brazil
Itaipu hydroelectric plant has an installed capacity of 14,000 MW and the second largest in the world. The facility, operated by the company Itaipu Binacional, is located on the Parana River on the border between Brazil and Paraguay. The investment in the construction of the plant was 15,000 million euros. The erection began in 1975 and was completed in 1982.
The Itaipu hydroelectric plant supplies about 17.3% of energy consumption in Brazil and 72.5% of the energy consumed in Paraguay. Specifically, it consists of 20 generating units with a capacity of 700 MW each, having come to achieve production in 2014 almost equal to the Three Gorges, reaching 98.5 TWh, making it virtually global co-leader by generation energy, although it is not installed capacity.
c. Xiluodu Hydropower Plant. 13,860 MW. China
The hydroelectric plant Xiluodu located on the Jinsha River, a tributary of the Yangtze River in its upper reaches, the river, is at the center of the province of Sichuan, is the second largest power plant in China and the world's largest third. The installed plant capacity reached 13,860 MW at the end of 2014 when the last two turbines generating were installed. The project was developed by the Three Gorges Project Corporation and is expected to generate 64 TWh of electricity per year when fully operational.
The project required an investment of 5,500 million euros, began construction in 2005, putting up the first turbines in July 2013. The plant consists of a dam arc of double curvature of a height of 285.5 meters and a width 700 meters, creating a reservoir with a storage capacity of 12,670 million cubic meters. The plant has 18 Francis turbines with a capacity of 770 MW each and an air-cooled with 855.6 MVA generator output.
d. Guri hydroelectric plant. 10,235 MW. Venezuela
Guri, also known as Simon Bolivar hydroelectric plant, is positioned as the fourth largest in the world with an installed capacity of 10,235 MW. The facilities are located on the Caroni River, located in southeastern Venezuela, being Electrificacion del Caroni C.A. (EDELCA) the owner and operator of the plant.
The construction project was initiated in 1963 taking place in two phases; the first was completed in 1978 and the second in 1986. The plant has 20 generating units of different capacities ranging between 130 MW and 770 MW.
e. HPP Tucuruí. 8,370 MW. Brazil
The Hydroelectric Complex is located at the bottom of the Tocantins River in Tucuruí, belonging to the State of Pará in Brazil stands as the central hydroelectric fifth largest in the world with 8,370 MW. The project construction required an investment of 4,000 million euros and initiated in 1975.
Hydroelectric power in the United States energy matrix
In 2015, the United States of America had an electricity generation of 4 trillion kilowatts hours of energy. Two-thirds of that energy was generated by fossil sources as petroleum, coal, and natural gas. Today the hydropower is the most important renewable energy source in the United States of America with 6%. The hydropower energy supports the other renewable energy sources that provide 7% of the energy generation, for example solar, wind, biomass and geothermal (US Energy Information Administration, 2015).
The country has the potential to increase in a 100% its hydropower capacity due to the approach of the Missouri, Mississippi, Yukon and Rio Grande rivers.
Reference List
National Geographic. (2015). Hydropower Facts. Retrieved from National Geographic: http://environment.nationalgeographic.com/environment/global-warming/hydropower-profile/
Power Technology. (2013). The 10 biggest hydroelectric power plants in the world. Retrieved from Power Technology: http://www.power-technology.com/features/feature-the-10-biggest-hydroelectric-power-plants-in-the-world/
US Energy Information Administration. (2015). What is U.S. electricity generation by energy source? Retrieved from EIA Frequently Asked Questions: https://www.eia.gov/tools/faqs/faq.cfm?id=427&t=3
