Note 1: this is a rough estimate of the energy consumption and nothing more. It does not calculate emission of greenhouse gasses or other pollutants.

Note 2: this is just a back of the envelope calculation. Feel free to improve.

Note 3: mix of imperial and metric units ahead :smile:

Note 4: I did not take the "overhead" into account to distribute diesel/gasoline from an oil field to the gas station, nor did I take the overhead into account to bring coal to the power plant. This also consumes energy.

Suppose you take the MS for a trip of 100 miles (160 km) and end up with an average consumption of 320 Wh/mile (200 Wh/km). So the car will have consumed 3,2 kWh. Suppose we don't use green electricity from solar panels or wind mills. We use brown electricity that is generated from coal or another source of energy. If I remember correctly, 3 kWh of primary energy sources (coal for instance) is needed to deliver 1 kWh of electricity at your home. This 3:1 factor takes into account the inefficiency of the turbine, transmission and distribution losses. In terms of primary energy source, The 3,2 kWh of electricity consumed by the MS represents, in terms of primary energy source (excluding sun and wind), 9.6kWh. Let's round this number to approximately **10 kWh**.

A typical (European) diesel car will consume 5,0l/100km (47 MPG). At the end of the trip, it will have consumed 8,0l (2.1 gallons) of diesel. How much primary energy does 8 liters of diesel represent? **80 kWh** (*)

A gasoline car that uses about 7,0 l/100 km (34 MPG) will require 11.2 liters (2.96 gallons) to do the same trip. How much primary energy does 11 liters of gasoline represent? **100 kWh** (**)

(*) diesel offers 35.86 MJ/l (source wikipedia).

This is equivalent to 35.86 * 10^6 J/l = 35.86 * 10^6 * Ws/l = (35.86 * 10^6) / (1000*3600) kWh/l = (35.86 / 3.6) * (10^6 / 10^6) = 9.96 kWh/l.

This means 8 liters represents 8.0 * 9.96 = 79.7 kWh i.e. approx. 80 kWh

(**) gasoline offers 32.18 MJ/L (source wikipedia).

This is equivalent to 32.18 / 3.6 = 8.94 kWh/l

This means 11.2 liters represents 11.2 * 8.94 = 100 kWh