Energy from Water: Hydroelectric, Tidal, and Wave Power
UDES of Energy A skier stands at the top of a mountain ready to begin the descent Being at the top of a steep slope gives her potential energy which is the energy an object has because of its position not its motion Once she uses her muscles to push off Earth's gravity will pull her down the slope Her potential energy turns into kinetic energy or energy from movement We use energy all the time in our daily lives Some of the energy we use harnesses the power of kinetic energy Blowing wind and flowing water are forms of kinetic energy that can be converted into electrical energy This electricity can then be used for many different things from charging a cell phone to powering a car We get our energy from other sources too We burn fuels such as coal or oil We generate heat energy from chemical reactions We use panels to collect energy from sunlight Hydroelectric power which is electricity generated from moving water is one of the cleanest energy sources in use However no energy source is perfect some create pollution some are too expensive and some contribute to the warming of Earth and global climate change This surfer depends on the kinetic energy of the wind to push the ocean's water into
Using Energy World Electricity Generation in 2012 5 22 5 Coal Natural gas Nuclear Earth's energy needs are increasing all the time The planet s population is increasing and each person uses more energy than they did a few decades ago Lifestyles have changed We have become used to traveling by car or airplane and depend on appliances and gadgets that make our daily lives easier These all require power in some form How can we continue to meet all of our energy demands Our challenge for the future is to find clean low cost sources of energy that are sustainable This means living in a way that conserves and efficiently uses natural resources 10 9 Hydroelectric Other 40 4 16 2 5 Hydroelectric power already makes up a si ficant percentage of the world's electricity supply R E WI N D For hundreds of years people have used the energy of the wind Sun and water in various forms For example the wind can fill the sails of a ship and push it forward or turn the blades of a windmill that grinds grain Today we harness their power to generate electricity Electricity lights our homes and powers our devices Do you think this is a better use of these natural forms of energy Give reasons for your
Moving Water The water on Earth's surface is rarely still Rivers flow from high ground to lower ground and wind pushes water into currents and waves that sweep across the world's oceans Rain falls from the sky to the ground All this shows that water has a lot of kinetic energy Thousands of years ago the ancient Greeks harnessed the power of moving water to turn waterwheels People also used moving water for transportation sending ships and barges loaded with goods from city to city on rivers This allowed them to transport loads that would be too heavy for horses or oxen to pull In the early 1800s engineers worked on ways to make waterwheels more efficient They could use waterwheels to power machines such as weaving looms in factories The first use of moving water to generate electricity was in a house called Cragside in northern England The house s owner developed his own hydroelectric factory that powered electric lighting The first commercial hydroelectric factory opened in Wisconsin in 1882 but it produced only a small amount of electricity Long ago waterwheels were often used to turn the heavy stones that ground grain into
Hydropower Today r The Wisconsin plant was the start of a type of new hydroelectric project Hydroelectricity makes up 7 percent of the electricity in the United States today In other countries the percentage is much higher For example Canada is the second largest producer of hydroelectricity after China Hydroelectricity makes up about 59 percent of Canada's electricity supply Most of this electricity comes from power plants built on rivers but we are starting to use the power of waves and tides too However although hydropower can be used to charge electric vehicles it cannot directly replace oil and natural gas for fueling engines The construction of the Three Gorges Hydroelectric Dam in China is still controversial After it was built huge areas of land were flooded on purpose forcing more than 1 million people to move from their homes and farms R E WI N D When the Fox River hydroelectric plant in Wisconsin was built it generated only enough electricity to light the plant itself and two other buildings Today the world's largest hydroelectric plant China's Three Gorges Dam generates huge amounts of electricity roughly equivalent to burning 49 million tons 44 5 million metric tons of coal Do you think hydropower can become even more efficient Explain your
