Energy resources and electricity generation

Name the 7 energy stores

• wind

• water

• geothermal resources

• solar heating systems

• solar cells

• fossil fuels

• nuclear power

Describe how wind generates electricity

- wind turbine

• kinetic energy stored in the moving wind.

• wind moves blades → connected to generator.

Describe how water generates electricity

(hydroelectric power)

• power plant uses reservoir.

• water released from reservoir flows through turbine, spinning it, and activating a generator.

• gravitational potential energy in water → kinetic energy store to drive turbine

Describe how geothermal resources generates electricity

• water pumped into the ground and heated.

• steam rises to drive turbines, attached to generator.

• thermal energy builds up pressure in steam → kinetic energy of escaping steam spins turbines.

Describe how solar heating systems reduce the need for electricity

• pipes on roof

• water pumped through the pipes

• radiation from sun transfers energy to thermal store of the water.

Describe how solar cells generate electricity

• convert light energy → electrical energy

Describe how fossil fuels generate electricity

• chemical energy store in fuel transferred into thermal energy store: water and steam.

• superheated steam at high pressure transfers energy into kinetic stores of turbines.

• turbines drive the generators.

Describe how nuclear power generates electricity

• initial energy = nuclear store of the nuclei

• nuclei undergo nuclear fission.

• kinetic energy store of nuclei → thermal energy store of water and steam.

• drives turbines and generators.

Advantages and Disadvantages of fossil fuels

Advantages

1. fossil fuels readily available

2. reliable source of power.

3. electricity companies able to respond to demand (power station)s turned on/off at short notice.

Disadvantages

1. non-renewable

2. produces carbon dioxide → global warming

3. coal burning stations → damages health

Advantages and Disadvantages of nuclear power

Advantages

1. nuclear resources will last for a long time

2. does not produce gases → no global warming

3. large amount of energy released for each kilogram of nuclear fuel.

Disadvantages

1. produces radioactive waste.

2. nuclear power expensive to produce.

3. nuclear accidents → contaminate environment.

Advantages and Disadvantages of wind power

Advantages

1. clean energy source.

2. renewable source

Disadvantages

1. wind power unreliable.

2. wind too light = no power

3. wind too high = turbines overheat and are turned off.

Advantages and Disadvantages of water power (hydroelectric power)

Advantages

1. hydroelectric power/tidal power reliable.

2. no waste products

3. power relatively cheap to provide.

Disadvantages

1. tidal power can only be used when tides are going out.

2. building hydroelectric power stations damages environment:

   • building a dam causes new lake to be formed.

   • habitats, forests, farmland destroyed.

Advantages and Disadvantages of geothermal power

Advantages

1. renewable and reliable.

2. no waste products.

3. cheap to provide.

Disadvantages

1. geothermal power only available in some regions of geological activity.

2. risks with building geothermal power station:

   • poisonous gases could be emitted.

Advantages and Disadvantages of solar power

Advantages

1. solar power is a free source (once panels installed.)

2. solar panels require little maintenance.

3. renewable

4. no waste products

Disadvantages

1. high initial investment.

2. panels can’t operate at night.

3. less effective in winter.

Advantages and Disadvantages of solar heating systems

Advantages

1. clean energy source.

2. renewable

3. low cost

Disadvantages

1. solar heating unreliable: weather dependent.

renewable energy resource

a resource that never runs out

-eg. wind, water, solar power

non-renewable energy resource

a resource with a limited supply

-eg. oil, coal, gas, nuclear