Otto engines are about 35% efficient - 35% of fuel energy arises at the output shaft, the remainder appears as waste heat.

The Air Force is the largest user of fuel energy in the federal government.

Gas provides the world, and especially the United States, with a large part of its total fuel energy.

It takes more fuel energy to grow the corn and process it for ethanol than the ethanol provides, he said.

Fossil fuel energy first exceeded all animal and water power in 1870.

"The typical diesel engine converts only about 35 percent of fuel energy into useful work," Dr. Wicks said.

The more energy is obtained from renewable sources, the less fossil fuel energy is required to provide that same energy demand.

To maintain our civilization we need to develop non-fossil fuel energy.

Biodiesel made from sunflowers may produce only 0.46 times the input rate of fuel energy.

Our current biased economic system which charges too little for fossil fuel energy is not geared towards this, however.