Water Powering the World
Hydropower, the generation of power from flowing water, is one of the most efficient forms of renewable energy, now providing about 16 percent of the world’s electricity.
Though today’s installations are on a huge scale, the power of water to create energy has been exploited since the time of the ancient Greeks. Kinetic energy of a flowing river has for centuries been used to turn water wheels, most commonly to grind wheat into flour.
It was in the late 19th century that hydropower became a source of electricity. The first hydroelectric power plant was built at Niagara Falls, Canada, in 1879 and by 1881, street lamps in the city of Niagara Falls were powered by hydropower.
A typical hydro plant is a system with three parts: a plant where the electricity is produced; a dam that can be opened or closed to control water flow; and a reservoir where water is stored. The water behind the dam flows through an intake and pushes against blades in a turbine, causing them to turn. The turbine spins a generator to produce electricity. The amount of electricity that can be generated depends on how far the water drops and how much water moves through the system. The electricity is then transported over long-distance electric lines.
Most used composite bearing material
“One of the world's largest hydro plants is the Three Gorges Dam on China's Yangtze River. The biggest hydro plant in the United States is located at the Grand Coulee Dam on the Columbia River in northern Washington,” says Tom Zozokos, Product Manager Orkot® Material. “Orkot® bearings feature in both of these installations. In fact, Orkot® is the world’s most used composite bearing material by the hydropower industry.”
Orkot® is an advanced composite material, which means it has significant advantages over traditional metal bearings for hydropower applications. “Orkot® bearings are ‘fish friendly’ as they can operate in dry running applications and do not use harmful lubricants in the manufacturing process,” continues Tom. “Most metal bearings need grease to make them work properly and during operation this lubricant can enter the water. That is not very good environmentally. Orkot® material has excellent friction characteristics, meaning no grease is required. Other types of bearing materials are available, but the Orkot® product is a very cost-effective and reliable alternative.”
Orkot® material has been manufactured since 1955, but that doesn’t mean that development does not continue.
“We’re always looking to advance our material portfolio for the hydropower industry and work with customers to meet their changing requirements. We’ve just added Orkot® C417 to our range of hydro bearing materials. This was developed for the U.S. market to be used in higher load bearing applications, while still giving customers low friction capabilities,” concludes Tom.
This article has been reproduced from in the groove, the Trelleborg Sealing Solutions magazine aimed at engineers. To read the full issue,In the Groove magazine.