P3

How do fossil fuels work

Fuel burned to boil water and produce steam to turn a turbine

Is it renewable, produce CO2 and produce SO2? (causes acid rain) - fossil fuels

N, Y, Y (coal only)

Advantages of fossil fuels

Gas - very short start up time, all - can be run continuously

Disadvantages of fossil fuels

Fuels need to be transported.

Mining for fuels can disrupt

How does nuclear power (uranium) work

Nuclear fission of Uranium

Advantages of nuclear power (uranium)

Not expensive to make

Doesn't produce smoke/CO2

Produces huge amounts of energy from little fuel

Produces small amounts of waste

Reliable

Is it renewable, produce CO2 and produce SO2? (causes acid rain) - nuclear power

N, N, N

Disadvantages of nuclear power (uranium)

Very dangerous -

Must be sealed up and buried for many thousands of years to allow the radioactivity to die away - kept safe from earthquakes/flooding/terrorists

A lot of money spent on safety - 1990s was the fastest growing power source 205 - second slowest growing

How does solar power work?

1. PV (photoelectric) cells convert light directly into electricity

2.Solar water heating - sun heats water in black pipes

3.Solar Furnaces - mirrors to concentrate the Sun's energy into a small space and produce very high temperatures

Is it renewable, produce CO2 and produce SO2? (causes acid rain) solar

Y,N,N

Advantages of solar power

Free - no fuel and produces no waste/pollution

Can be used when there is no easy way to get electricity to a remote place

Handy for low-power uses e.g. solar powered garden lights - home energy bill

Disadvantages of solar

Doesn't work at night

Very expensive to build stations - cost coming down. Cost more than they'll produce

How does wind power work

Sun heats atmosphere unevenly, warm patches of air rise other air blows to replace them - wind blows the propellor round, turning a generator -> electricity

Is it renewable, produce CO2/SO2 and is it unreliable? wind power

Y,N,Y (only when windy)

Advantages of wind power

Wind = free - no fuel

No waste/greenhouse gases

Land beneath can still be used for farming

Supplying energy to remote areas

Disadvantages of wind power

Not always predictable

Wind farms near the coast - land expensive

Can kill birds

Affect tv reception

Low swooshing noise sound pollution

How does tidal power

Water trapped behind barrage at high tide.

At low tide the water behind the barrage has higher GPE.

When the water is let through the barrage the GPE is converted to KE

Only available at certain times? Certain place? Tidal power

Linked to tides (twice a day), At a tidal estuary. Tidal barrage needed

Advantages of tidal power

No fuel costs

Does not produce CO2 or SO2

Disadvantages of tidal power

Barrages can disrupt river traffic and wildlife.

How does hydro-electric power work?

Dam traps water (from rain) , water is allowed to flow through tunnels in dam to turn turbines and drive generators. GPE à KE

Certain area for hydroelectric?

Place to trap water - valley with lake - reservoir - hilly

Advantages for hydro-electric

Once dam built - energy free

No waste/pollution

More reliable than others

Water can be stored above the dam - for peak demand

Increase to full power quickly

Generated constantly

Disadvantages of hydro-electric

Dams expensive to build but can be used for flood control/ irrigation

Large dam will flood a very large area upstream - animals :(

Water quality + quantity downstream can be affected - plant life

How do pumped storage reservoirs work?

Water pumped up to the top reservoir at night when power demand is low. Headgates opened and water rushes down the tunnels to drive the turbines - drive powerful generators. Collects in the bottom reservoir ready to be pumped back

Certain area for pumped storage reservoirs?

Hilly area

Advantages for pumped storage reservoirs

Without some means of storing energy for quick release, we'd be in trouble

Little effect on the landscape

No pollution or waste

Disadvantages of pumped storage reservoirs

Expensive to build

Once used, you can't use It again until water is pumped back up. Industry good at predicting the surge of power demand so good planning can combat problem

How does wave power work?

Waves cause the water in the chamber to rise and fall -> air is forced in and out of the hole in the top of the chamber - turbine in hole - turned with air rushing around - turbine turns generator

Certain area? Wave power

Where there are waves

Advantages of wave power

The energy is free - no fuel needed and no waste produced

Not expensive to operate and maintain

Can produce a great deal of energy

Disadvantages of wave power

Depends on the waves, needs a suitable site where waves are consistently strong, some designs are noisy, must be able to withstand very rough weather

How does geothermal power work?

Hot rocks underground heat water to produce steam. Drill holes down to hot region, steam comes up, is purified and used to drive turbines -> drive electric generators. May be natural groundwater in hot rocks

Certain area? geothermal power

Place with hot rocks that you can drill down to them

Advantages of geothermal power

Doesn't produce any pollution, does not contribute to the greenhouse effect

Power stations do not take up much room --> not much impact on the environment

No fuel needed

Once built, the energy is almost free - may need a little energy to run a pump but this can be taken from the energy being generated

Disadvantages of geothermal power

Not many places where you can build a geothermal power station

Type of rock above that you can drill through

Geothermal site may run out of steam

Hazardous gases and minerals may come up from underground and can be difficult to dispose safely.

How does biomass, biogas and biofuels work

Biomass:

Burn Fuel -> Heat water to make steam -> steam turns turbines -> turbines turn generators -> electrical power

Biogas:

Biodegradable organic material -> anaerobic digestion (fermentation b bacteria) -> storage and distribution

Biofuels:

Crops like corn sugar cane soya or rapeseed or palm oil or algae

Is it renewable, produce CO2 and produce SO2? (causes acid rain) biomass, biogas and biofuels

Y, Y (Biogas: If material started with is manure, sewage or greenhouse was), N

Advantages of biomass, biogas and biofuels

Biomass:

It makes sense to use waste materials where we can

Buel tends to be cheap

Less demand on the fossil fuels

Biogas:

The methane gas from the waste would otherwise end up in the atmosphere and methane is a worse greenhouse has than co2

Fuel tends to be cheap

Less demand on the fossil fuels

Biofuels:

Less demand on the fossil fuels

Biofuel production is lower to being carbon neutral than using fossil fuels

Disadvantages of biomass, biogas and biofuels

Biomass:

Collecting or growing the fuel in sufficient quantities can be difficult

Makes greenhouse gases

Some waste materials are not available all year round

Biogas:

We burn the biogas, so it makes greenhouse gases

Biofuels:

It takes huge areas of land in order to grow crop for biofuels - biofuels from algae doesn't have problem

We burn the biofuel so it makes greenhouse gases - offset by the CO2 taken in by the plants as they grow

Some of the materials are not available all year round

Name power station steps (with energy stores + transfers)

1. Fuel burnt in a furnace (fuel chemical store --> thermal energy store of fuel in furnace)

2. Furnace is connected to a boiler which boils the water and produces steam. (Boiler - thermal energy of fuel --> thermal energy of water)

3. The steam rises and turns a turbine (thermal energy of water --> KE steam)

4. The turbine is connected to a generator (KE steam --> KE of turbine, KE of turbine --> KE of generator)

5. Generator transfers electricity o the national grid (electrical transfer)

Name disadvantages of renewable energy in general

Location, unreliable, not able to meet demand

What is the national grid

A system of cables and transformers linking power stations to consumers

Step-up transformer

Increases the potential difference from the power station to the transmits in cables

Step-down transformer

Decreases (much lower value) the potential difference for domestic use