how fossil fuel use by the central heating compares with fuel use by a car

Our climate sorts into six cold months when we need to run the central heating and six months when we don’t. For many of us (still unfortunately) that involves burning fossil fuels such as natural gas, or in my out-of-town place use ‘heating oil’ (aka kerosine or airplane fuel). I’ve been measuring how much fuel I use which led to an interesting comparison: heating a home requires a similar amount of energy to running a road vehicle.

how much energy do we need to heat a home in the cold season

• Example 1: heating a Flat/Apartment (50 square metres area) consumes 6,000kWh of thermal energy per year. The amount of energy varies with the building but this flat needs that, regardless of what method we use to heat it. A 15kW fossil fuel boiler runs for 300 total burn hours  (1¾ hour/day). If our heating fuel is oil this will consume 600 litres of fuel at a cost of £600.
• Example 2: heating an under-insulated House requires about half as much more than the flat: we’d consume 10,000kWh of thermal energy per year regardless of the method we use to heat it. If we use oil we’ll consume 1,000 litres of heating oil costing £1000

how much energy do we need to run a car for the year

• Driving a Car: Burning 600 litres of diesel in a car that manages 60mpg at 60mph will take us 8,000 miles. I’ve chosen this example for easy maths but read on for petrol*. My example diesel car outputs a steady 18kW to the wheels takes 130 driving hours (¾ hour/day). At £2.00/litre for road fuel, this costs £1,200.
• *Burning 600 litres of petrol in a car that manages 50mpg at 60mph will take us 6,600 miles. My example petrol car outputs a steady 18kW to the wheels takes 110 driving hours (⅝ hour/day). At £1.50/litre for road fuel, this costs £900.

takeaway facts:

• Energy use: The energy required to heat a flat/apartment equates to the energy to run a diesel car doing 8000 miles (per year). Or a petrol car doing 6000 miles.
• Energy use: The energy required to heat an (old) house equates to the energy to run a diesel car doing 13000 miles (per year). Or a petrol car doing 10000 miles.
• Fuel consumption: Cruising at 60mph in a diesel car burns approximately 1 UK gallon per hour (4.55L/hr)—using fuel more than twice as fast as a central heating boiler (2L/hr). (A petrol car would use about 1.2 gallons per hour).
• Efficiency discrepancy: A modern heating boiler converts >90% of fuel energy directly into space heating. Internal combustion engines are only 30–35% efficient, losing roughly two-thirds of input energy as waste heat.
• Volume vs. Cost: 600 litres yields 300 hours of home heating or 8,000 miles of road transport. However, road fuel costs twice as much due to taxation.
• Carbon issues: every fossil fuelled house = another fossil fuelled car