Among the Mount Everest of inanities ever uttered on the subject of energy, the blue-ribbon winner must be this: “the tyranny of oil.”
Both Barack Obama and Robert F. Kennedy Jr. have used the line. Obama claimed it for his own back in 2007 when he declared his run for the White House. Standing on the steps of the Old State Capitol in Springfield, Ill., Obama said, “Let’s be the generation that finally frees America from the tyranny of oil.”
In a speech at Sandhills Community College in North Carolina earlier this month, Kennedy, a high-profile opponent of the Keystone XL pipeline (he was arrested at the White House during a recent protest), said that “we need to free ourselves from the tyranny of oil.”
Let’s be clear here: I’m no Kennedy. And I don’t have the political savvy or oratorical skills of Obama. Both of them went to Harvard. I didn’t. But the claim that a super-high-energy-density substance that can be deployed for myriad purposes — from pumping well water in Kenya to emergency generation of electricity in Lower Manhattan — is somehow bad or even tyrannical is ludicrous. And for two leading political figures in America to use such a phrase, “tyranny of oil,” demonstrates once again just how polluted our energy discourse has become.
The wealth and power that are achieved through the finding and burning of hydrocarbons are enormous. That much is indisputable. And of the hydrocarbons — coal, oil, and natural gas — oil is the unchallenged king. No other substance this side of uranium comes close to oil with respect to energy density — the amount of energy, measured in joules or BTUs, that can be contained in a given volume or mass. Moreover, the products that can be produced from petroleum are relatively cheap, easily transported, usually stable at standard temperature and pressure, and essential for everything from making shoelaces to fueling jumbo jets.
Demonstrating the wondrous qualities of oil requires only a simple bit of math and a look at one of the most famous airplanes in aviation history: the Boeing 737. To make the math easy, let’s use metric units. And let’s focus on weight, as that factor is critical in aerospace. The gravimetric energy density of jet fuel is high: about 43 million joules per kilogram. (Low-enriched uranium, by the way, is 3.9 trillion joules per kilogram.)
A fully fueled 737-700 holds about 26,000 liters of jet fuel, weighing about 22,000 kilograms, containing about 902 billion joules (902 gigajoules) of energy. The maximum takeoff weight for the 737-700 is about 78,000 kilograms, and so jet fuel may account for as much as 28 percent of the plane’s weight as it leaves the runway.
Obama and Kennedy are big fans of electric cars. If we wanted to end the tyranny of oil onboard the 737, how many lithium-ion batteries would we need? That’s a pertinent question, as Boeing’s decision to use lithium-ion batteries to power auxiliary systems in its new 787 Dreamliner has led to onboard fires. The 787 has been grounded as the company tries to solve the problem.
Lithium-ion batteries have higher energy density than most other batteries, holding about 150 watt-hours — 540,000 joules — of energy per kilogram. Recall that jet fuel contains about 43 million joules per kilogram, or nearly 80 times as much energy. Therefore, if Boeing tried to replace jet fuel with batteries in the 737-700, it would need about 1.7 million kilograms of lithium-ion batteries. Put another way, to fuel a jetliner like the 737-700 with batteries would require a battery pack that weighs about 22 times as much as the airplane itself.
Prefer to use a “green” fuel like firewood? With an energy density of about 16 million joules per kilogram, that same 737-700 would require about 56,000 kilograms of wood to be stowed onboard. With that much kindling, you can be assured there won’t be room in the overhead bin for your carry-on.
The only “tyranny” at work in our energy and power systems is that of simple math and grade-school physics. Obama and Kennedy may not like oil, and their allies may particularly hate Exxon, Chevron, and Keystone XL, but here’s the reality: If oil didn’t exist, we would have to invent it. It’s a miracle substance.
Rather than condemn the fuel that makes modern life possible, our political leaders should be figuring out how we can make that miracle energy form more available to more people at lower cost.