Investigating Costs of Energy Sources (WJEC GCSE Physics: Combined Science)

• Homes can be heated using a variety of fuels
• The most common type of heating system in the UK runs on natural gas
• Homes can be heated by:
  • Gas boiler central heating
  • Electric heaters
  • Log burner
  • Open fireplace (coal or wood)
    • Using coal has been illegal in England since 2023 
  • Bio-ethanol open fireplace
  • Oil central heating system
  • Biofuel central heating system
  • Bottled gas heaters
    
    • Butane
    • Propane
  • Generators 
    • Petrol
    • Diesel
    • Biofuel (bio-ethanol produced from crops)

• Gas and electricity are charged per unit (kWh) used, but there is also a standing charge
• A standing charge is the cost associated with being connected to the mains supply
  • The average standing charge for gas is 29.6 p per day (£108 per year)
  • The average standing charge for electricity is 55.25 p per day (£202 per year)

• Bottled gas initially has the additional cost of having to purchase the bottles
• After the initial purchase, the bottles can be refilled
  • The average cost of an empty bottle is around £50 depending on the size
  • For example, a new (filled) 7 kg bottle of butane gas is around £83 and the cost of a refill is £33

Different Sized Bottles of Butane Gas

Bottled gas like propane and butane are also used for gas BBQs, gas firepits and outdoor heating 

 

Comparison of Different Fuel Types for Heating Systems

Fuel Type	Cost per unit / p	Unit	Cost per kW of fuel / p	Energy content / kWh per unit of fuel	CO2 emission kg per kWh
Gas	7.4	kWh	7.4	1.0	0.2
Electricity	28.6	kWh	28.6	1.0	0.5
Wood	104	kg	24.8	4.2	0.003
Coal	24	kg	1.7	6.9	0.4
Oil	76	litre	7.3	10.4	0.3
Propane (refill)	467	kg	65.8	7.1	0.2
Butane (refill)	471	kg	58.9	8.0	0.2
Petrol	140.6	litre	14.5	9.7	0.3
Diesel	149.3	litre	14.9	10	0.3
Bio-ethanol (crops)	350	litre	53.8	6.5	0.1

• Cars, vans, motorbikes, and other vehicles need fuel to run
• Vehicles can be fuelled by:
  • Petrol
  • Diesel
  • Electricity
  • Biofuels
• The prices of petrol and diesel fluctuate daily depending on:
  • The global price per barrel of crude oil
  • The global availability of crude oil
  • The global demand for crude oil
  • The national availability of petrol and diesel
  • The national demand of petrol and diesel
  • Taxes imposed by my the government
• All petrol and diesel sold in the UK has a percentage of biofuel mixed in to lower carbon emissions