Two important articles from Alice Friedemann at energyskeptic.com
Muscle Power. “As fossil energy declines, muscle power will increasingly have to replace it.”
From Horsepower to Horse Power. When Trucks stop, Horses start. “Just as horses were indispensable the past millennia, so have the cars and trucks of the 20th century become essential to our way of life. If one horsepower equals the power one horse can generate (this is roughly true), then the 268.8 million cars and trucks in the United States, let’s say with an average horsepower of 120 HP, then that’s nearly 32.3 billion horses. If each needs an acre of pasture, then that’s over 50 million square miles of land. But the U.S. is only 3.5 million square miles. Clearly we can’t go back to horses – except we have to at some point because oil is finite (I’m assuming you’ve read my book “When Trucks Stop Running: Energy and the Future of Transportation” to understand why biofuels, CTL, batteries, overhead wires, natural gas, and hydrogen can’t replace petroleum powered internal combustion engines).”