4.17 describe the advantages and disadvantages of methods of largescale electricity production from various renewable and nonrenewable resources.

  • Renewable energy – energy that lasts forever, eg. solar and wind (key term: sustainable)
  • Non renewable energy – energy that has a finite number of resources

Cost –

  • Renewable energy initial start up costs are very very expensive
  • With nuclear stations, a considerable cost is spent on safely decommissioning a reactor

Renewable / non renewable –

  • Reserves of fossil fuels are finite, eventually we will need to find alternate sources
  • Petroleum is often used in plastic and pharmaceuticals

Greenhouse gas emissions –

  • Burning fossil fuels produces CO2 (greenhouse gas)
  • Greenhouse gasses trap heat in the atmosphere and contribute to global warming

Supply and demand –

  • Demand for electricity will vary over a period of 24 hours
  • Nuclear reactors cannot respond to demand surges as they cannot be turned on and off quickly
  • Gas fired power stations – extra generators are able to meet such demands, but are using tonnes of non-renewable energy
  • Solar and wind don’t produce energy all the time

Environmental impact –

  • Power stations are sight pollutants
  • Waste products damage plant and animal life in the area of power stations
  • Hot water waste has huge impacts on rivers

Location –

  • Power stations can be built within the area of demand (this is because energy is wasted in the transmission)
  • Renewable energy sources eg. tidal and geothermal are limited to suitable geographical locations, often very far away from the area of demand
Advertisements

4.16 describe the energy transfers involved in generating electricity using

  •  wind –> KE from wind turns turbine –> turns generator –> produces electrical energy
  •  water –> KE from water –> turns turbine –> turns generator –> produces electrical energy
  • geothermal resources –> Thermal energy heats water –> water turns to steam –> Thermal energy from steam turns turbine –> turbine turns generator –> produces electrical energy
  • solar heating systems –> light energy from sun –> thermally heats water
  • solar cells –> Light energy –> electrical energy
  • fossil fuels –> Chemical energy burnt –> heat energy –> water –> KE in a turbine –> electrical energy –> generator
  • nuclear power –> KE –> uranium –> heat energy –> water –> KE turns turbine –> electrical energy

4.13 understand how conservation of energy produces a link between gravitational potential energy, kinetic energy and work

ba7b6520d98cee3dc852a0e584ca1341abdaf3b4.gif

  1. At the highest point of the swing, it has the highest GPE as it is far from earth, and has the lowest KE, as it slows to the stop point
  2. Bottom of the swing, lowest GPE as it is closest to earth, highest KE as it goes quickly past the bottom point
  3. Between the points: Pendulum upwards : work is being transferred from KE to GPE
  4. Pendulum downwards : Work is being transferred from GPE to KE
  • The pendulum demonstrates that energy is conserved, changing between different forms.
  • Energy can be lost from the pendulum because it slows down/energy is transferred into heat or sound