Burning fuel to learn to save energy

Ironically enough, I flew from Los Angeles International Airport to Dulles International outside of Washington, DC to attend the ARPA-E Energy Innovation Summit. The speakers include former California Governor Arnold Schwarzenegger and Department of Energy Secretary Dr. Steven Chu. The purpose of the Summit is to bring together developers of disruptive energy technologies, venture capitalists, regulators, and ARPA-E officials to discuss opportunities, successes, and failures. Frankly, I'm quite excited to be here.


But...anyone could be forgiven for thinking that this is a bit reminiscent of climate change conferences taking place in Bali. I wonder how many joules of stored fossil fuel energy were converted to dissipated thermal energy in the process of putting on such a conference? An estimate of that number will have to await my attendance so that I can determine the number of attendees, where they're from, what was hauled in to display, etc.


But I certainly converted a lot of fuel on the way here, and will convert more when I return to California on Thursday. I flew on an American Airlines Boeing 737-800. The flight was direct and, according to Wolfram Alpha, the distance was about (because the flight couldn't be quite direct) 2,288 miles. According to Wikipedia, in a two class layout (I flew coach, of course), this aircraft carries 162 passengers and was completely full.


On the way out of the aircraft, I asked the First Officer how much fuel had been burned on the flight, and he kindly checked his documentation and stated that the burn had been "just a bit under 20,000 pounds." I'm going to go with 20,000 since I have no firm definition of "just a bit." Using figures from Wikipedia again, the density of Jet-A fuel is 804 kilograms/meter^3 or 6.710 pounds per gallon so the flight burned 2,981 gallons of fuel. So the aircraft achieved 2,288/2,981 or 0.7675 m.p.g. But it did so while carrying 162 passengers, and so it achieved 124 passenger m.p.g. This is a slightly better figure than would be achieved in a car carrying 4 passengers at 30 m.p.g. And it did so at something like 550 m.p.h. I realize that carbon dioxide spewed into the atmosphere at 37,000 feet is more harmful than that emitted on the ground but this is still pretty impressive efficiency and is a testament to engine and aircraft designers.


I expect to come away from this conference with a much firmer grasp on the extent to which it is reasonable to expect such a means of transportation to be available in the future.