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Question 1.2: Compare the costs of electricity at 1 p per kWh and gas at 1...

Compare the costs of electricity at 1 p per kWh and gas at 15 p per therm.

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Each cost is calculated in p/MJ.

1 kWh = 1 kW × 1 h = (1000 J/s)(3600 s) = 3,600,000 J or 3.6 MJ
1 therm = 105.5 MJ
∴ cost of electricity = 1 p/3.6 MJ or (1/3.6) = 0.28 p/MJ
cost of gas = 15 p/105.5 MJ or (15/105.5) = 0.14 p/MJ

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