## Transportation energy use

Since energy is a topic of conversation in our office, and I have been doing some bicycle commuting, it suddenly became important to have a table of transportation energy use.

 Mode kW-h/km kcal/mile Miles/gallon kW-h/mile beer-pints/mile Bicycle 0.0361 50 629 0.058 0.23 747 0.2521 350 90 0.407 1.59 Electric Car 0.1550 215 146 0.250 0.98 SUV 1.5128 2098 15 2.440 9.54 Train 0.0820 114 277 0.132 0.52

Conclusions:

• Bicycle wins the efficiency contest.
• Electric car could win the efficiency contest if you fit 5+ people in your car.
• Escalating that war, the tandem would probably be the next weapon of choice.
• Trains are pretty good (no surprise), and perhaps could get better with regenerative braking.

Assumptions:

• Bicycle uses 50 kcal/mile
• 747 90 mpg (FAA figure is lower,but…)
• Electric car: .25 kwh/mile (from Tesla  if you trust software ‘geniuses’  posing as a car company, or if you trust the old fashioned car company GM, their ‘Volt’ appears to be .34 kW-h/mile)
• <rant> Tesla presents data like a software vendor (no surprise).  Their claim a 70amp @220 volt charger, running for 3.5 hours charges the battery fully (capacity listed as 55kw-h). Energy = efficiency (always less than 1.0) x 70 x 220 x 3.5 = 53.9. Clearly credibility = 1/ efficiency </rant>
• SUV 15 mpg
• Train (swiss) .082kwh/passenger-mile
• Pint of beer has 220 kcal
• kcal (kilocalories) are the kind we eat (aka Calories with a big ‘C’)  Yep, our system of measurement is THAT stupid. Small calories x1000 = Calories =  kilocalories.

Conversion Notes:

• It’s assumed that all liquid fuels have the same energy content as gasoline: 36.6 kwh/ gallon.
• Liquid fuels have crappy energy conversion, unlike electricity which can be 100% efficient.