"In the US, for every 100 units of energy that we introduce into our economic system nearly 98 units are wasted," according to Paul Hawken, the author of Natural Capitalism. "That's right, we are 2 percent efficient."
"If you doubt the 2 percent figure, consider two common energy devices, your car and a light bulb," Hawken explains. "After a century of engineering, the modern car is still in the Iron Age. Of the energy consumed, about 80 percent is lost, mainly in heat and exhaust. Of the 20 percent that gets to the wheels, only 5 percent moves the driver. Five-percent times 20 percent equals 1 percent, a level of inefficiency that means cars burn their weight every year in gasoline. In the case of incandescent light bulbs, 100 percent of the energy input to the lamp becomes heat; only 8 percent becomes light en route to heat. It's essentially a space heater that glows. "
Via an email from my dad.