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

  • 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

Three Gorges

  • Largest power plant in the world

  • Displaced millions of people

  • 22 GW power continuous

  • NYC - 10 GW

Three Gorges

Three Gorges

Three Gorges Satellite

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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