- A very small number of prime movers have been used throughout human history: human and animal power since the Agricultural Revolution, sail, waterwheels and later windmills by the Middle Ages; and the steam turbine, the gasoline engine, the diesel engine and the gas turbine in the Industrial Age.
- Diesel engines and gas turbines (a.k.a. jet engines) are markedly more efficient than the next-best technology for the critical-for-globalization applications of large-scale shipping and flight, respectively. Despite approaching technological asymptotes (the basic designs of Rudolf Diesel, Frank Whittle and Hans-Joachim Pabst von Ohain are still recognizable, and conversion of energy efficiency is near theoretical maxima), they’ve enjoyed “prime mover primacy” for half a century or more, and it’s not even close.
- Nor are any likely replacements on the horizon, so we can predict with remarkable confidence that they will remain dominant for another half century or more. Their use will depend on fuel prices, so in a peak oil scenario it could diminish, but there’s not an alternative way to ship petroleum, ore, grains, and manufactured products from Brazil to China to America, etc.
- Biofuels will never dent fossil fuel consumption by these prime movers. Biodiesel from palm oil has ~2x the land intensity of corn ethanol and ~4x that of sugarcane ethanol, and biodiesel from temperate crops is almost an order of magnitude worse. Supplying marine diesel demand from palm oil would require 1/3 of the land currently under cultivation globally for agriculture. Smil believes algae will never scale economically, although the supporting evidence for this is less clear.
- Rudolf Diesel was a bit of a socialist and hoped the diesel engine would enable small industry to compete with large; as he grappled with late in his life, it instead enabled industry and trade on a hitherto unimagined scale, and whether the world is a happier place for this is hard to say.
Prime Movers of Globalization: The History and Impact of Diesel Engines and Gas Turbines by Vaclav Smil (who I love) was the first of two books recommended by Tyler Cowen that I devoured in the past ten days (only available in hard copy, so great for plane take-off and landing when the Kindle is forbidden). The book is technical but fascinating, and recommended; the rest of this post will be more of an attempt at synthesis for intellectual diary purposes rather than a critical review.