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Electricity · Chapter 6: Renewable electricity

Year 11 Science · About 15 minutes with activities · Turn your sound on

Chapter 6 · Renewable electricity
Mostly renewableusually over 80% of NZ’s electricity
Hydro
Wind
Geothermal
Solar
Turbinesomething makes it spin
Generatorcoil turns in a magnetic field
Electrical energy
Kinetic (turbine)→Electrical
Water up highgravitational potential energy
Rushing waterkinetic energy
Turbine + generator
Electrical energy
Gravitational potential→Kinetic→Electrical
Heat from the Sun
Warm air rises
Cool air sinks
Wind turbineblades drive the generator
Wind farmturbines grouped together
Kinetic (wind)→Kinetic (turbine)→Electrical
Hot rockdeep underground
Steam rises
Turbine + generator
Water pumped back
Heat (steam)→Kinetic (turbine)→Electrical
Fusion in the Sun
No turbine, no moving parts
Photona packet of energy
Electrons excited
DCone direction only
Remote hutno national grid here
Cloudy or nightlittle or no power

Chapter 6 recap

  • Hydro: gravitational potential energy of the water → kinetic energy of the falling water → electrical energy. Wind: kinetic energy of the wind → kinetic energy of the turbines → electrical energy.
  • Geothermal: heat energy (steam from deep underground) → kinetic energy of the turbines → electrical energy. Hydro, wind and geothermal all spin a turbine and generator.
  • Solar cells convert light energy directly into electrical energy: photons (packets of energy from fusion in the Sun) excite electrons, giving DC. Renewable, cheap to run, no polluting gases, works off-grid; but not very efficient, expensive to build, unreliable.
  • Course complete: magnets → electromagnets → generators → the grid → nuclear → renewables. Revise any chapter from the home page.

How do water, wind, steam and sunlight become electricity?

Chapter 6 · About 15 minutes · sound on

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