Hydropower
Hydropower
Energy Conversion
Solar radiation evaporates water
Wind currents from solar air heating move evaporated water to locations where it falls as rain
Gravity carries water down hill
Hydropower uses this gravitational potential energy and kinetic energy of the water to spin a turbine
The turbine is connected to a generator, creating electricity
Ancient Power Technology
Waterwheels have been used for centuries
Modern hydropower technology has added large scale dams
Energy basics
We use the simplest model for the water as a mass at a height or elevation
A mass $m$ lifted to a high $h$ has a stored gravitational potential energy of
PE is in joules if mass is in kilograms, g = 9.8 m/s^2^ and the height is in meters
Power
How do we convert this to a power?
To get flow in mass per time we convert from volume per time
Types
Run of river
Dams
Hydropower is significant world wide
2010 Hydropower 15.9% of world wide electricity
Coal 40.5%, Nuclear 12.8%
Largest power station in the world is hydroelectric
Three Gorges
Largest power plant in the world
Displaced millions of people
22 GW power continuous
NYC - 10 GW
Three Gorges
Three Gorges
Grand Coulee
Largest hydroelectric installation in US
6.8 GW capacity
21 Billion kWh annual energy delivered
Building a dam
What is the effect of a dam?
How does the dam affect the overall flow of water?
Advantages
Once built, very cheap power
Reliable technology
Can be used as storage
Disadvantages
Fish migration
Environmental impacts
Seasonal variation affects electricity supply
Water flow
Sedimentation
Increased seismic activity
Risk of dam failure
Methane production from vegetation decomposition
Hydropower
Hydropower
Hydropower
Hydropower
Hydropower similarities to fossil generation
Uses spinning generators just like combustion plant
Doesn't use heat, unlike combustion plant
Hydropower turbines
Hydropower turbines
Hoover Dam
Hoover Dam
Scalability
Hydropower can be produced at small scale
Hydropower
Hydropower
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