Fossil Fuels

Question 1

Describe the general cycle of a fossil fuel power station and draw a diagram.

Answer 1

Fossil fuel is burned to create heatt which boils water to produce steam. This steam then spins a turbine to create electricity via a generator. The steam then passes through a condenser back to a liquid and the cycle repeats.

Question 2

Formula for Carnot efficiency

Answer 2

n = 1 – T2 / T1 (T1 is heat supplied, T2 is heat rejected)

Question 3

formula for endoreversible efficiency

Answer 3

n = 1 - sqrt(T2-T1)

Question 4

Describe a combined cycle gas turbine and draw a diagram

Answer 4

Gas is used as fuel in combustion which drives a turbine which then creates electricity via a first generator. The excess heat given off from the turbine is then used to heat water which drives a steam turbine linked to a second generator. This is condensed and repeated.

Question 5

Dangers of burning fossil fuels

Answer 5

They produce large amount of emissions like soot, sulphur dioxide, hydrocarbons and nitrogen and CO2.

Question 6

Example of a coal power plant

Answer 6

Draw power station, largest in the UK, has 6 3.9GW turbines.

Question 7

List 4 advantages of Fossil fuel power stations

Answer 7

-They provide extremely reliable energy source.
-They provide a substantially high amount of energy, large capacity.
-Limit harm to the transmission network due to constant and stable power generation.
- High efficiency

Question 8

List 3 disadvantages of fossil fuel generation

Answer 8

• Creates large amounts CO2 which is expelled into the atmosphere.
• They are a finite resource which will eventually run out. They are not sustainable and will not last forever.
• Easily create extreme accidents including fracking, oil spills. Damaging the earth.

Question 9

What is being done in the UK to reduce fossil fuels.

Answer 9

• Incentivised renewable construction and generation from the government.
• Carbon taxes
• Pressure to reduce carbon footprint across all sectors.
• Increase in renewable generation and ways to decrease fossil fuel power plants. Increased transmission grid flexibility for renewable sources.
• Carbon capture and storage technology allowing for CO2 to be produced without releasing to the atmosphere.