# Shared Flashcard Set

## Details

Chapter 6 Hydroelectricity
17
Physics
06/30/2010

Term
 What percent of the planet is fresh water?
Definition
 3%
Term
 Surface water is what percent?
Definition
 .3% of the 3% that is freshwater
Term
 How much freshwater withdrawn from rivers and lakes goes to cooling power plants?
Definition
 39%
Term
 What is the biggest user of water?
Definition
 Agriculture
Term
 Water energy resources in the US
Definition
 300,000 MW
Term
 US available water power potential
Definition
 165,000 MW
Term
 What is more important than oil crisis?
Definition
 Water
Term
 What is the average flow:
Definition
 Nuclear 92%Wind 21%Photovoltaic 15%
Term
 Parts of a hydroelectric plant:
Definition
 Dam – Raises the water level of the river • Turbine – The falling water pushes the blades of the turbine andthereby causes the turbine to spin• It converts the kinetic energy of following water to mechanical energy• Generator – The turbine causes the generator to spin and hence converts the mechanical energy from the turbine to electric energy• Transmission lines- Theses are used to conduct the electricity from the hydropower plant to homes and business
Term
 Calculate power of a dam
Definition
 Engineers have found that we can calculate the power of a dam using the following formula:• Power = (Height of Dam) x (River Flow) x (Efficiency) / 11.8 ”
Term
 How much energy can a dam make?
Definition
 “To get an idea what 339 kilowatts means, let's see how much electric energy we can make in a year• Since electric energy is normally measured in kilowatt-hours, we multiply the power from our dam by the number of hours in a year.• Electric Energy = (339 kilowatts) x (24 hours per day) x (365 days per year) = 2,969,000 kilowatt hours.• The average annual residential energy use in the U.S. is about 3,000 kilowatt-hours for each person”
Term
 Three types of power plants
Definition
 Impoundment • Diversion • Pumped Storage
Term
 Dams in the US
Definition
 In the United States, there are about 80,000 dams of which only 2,400 produce power• The other dams are for recreation, stock/farm ponds, flood control, water supply and irrigation”
Term
 Size of hydroelectric power plants
Definition
 They range from large power plants that supply many consumers with electricity to small and micro plants that individuals operate for their own energy needs• Large Hydropower – DOE defines large hydropower as facilities that have a capacity of more than 30 megawatts• Small Hydropower – DOE defines small hydropower as facilities that have a capacity of 100 kilowatts to 30 megawatts• Micro Hydropower – have a capacity of up to 100 kilowatts. They can produce enough electricity for a home, farm, ranch or village
Term
 Types of hydropower turbines
Definition
 Impulse • Reaction• The type of hydropower turbine selected for a project depends on:• The height of standing water – referred to as “head” • The flow or volume of water • The depth at which the turbine must be set • Efficiency• Cost
Term
 Types of hydrocarbon turbines
Definition
 Impulse turbine, Pelton, Cross flow, Reaction Turbine, Propeller
Term
 Propeller turbines for water
Definition
 Bulb turbine - The turbine and generator are a sealed unit placed directly in the water stream• Straflo – The generator is attached directly to the perimeter of the turbine• Tube turbine – The penstock bends just before or after the runner allowing a straight line connection to the generator• Kaplan – Here, both the blades and the wicked gates are adjustable, allowing for a wide range of operation
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