Selected Facts from Energy and Civilization: A History
Excerpts from Vaclav Smil's Energy and Civilization: A History
Vaclav Smil is a Czech-Canadian scientist and policy analyst who currently teaches at the University of Manitoba. His Energy and Civilization: A History contains a number of interesting and sometimes insane facts. Here are a few of them:
In 1800, New England Farmers (seeding by hand, with ox drawn wooden plows and brush harrows, sickles, and flails) needed 150-170 hours of labor to produce their wheat harvest. This means they needed 7 minutes to produce a kilogram of wheat. By 1900, after the introduction of horse-drawn gang-plowing, spring-tooth harvesting, and combine harvesting, California farmers needed only 30 seconds, a 20-fold increase in productivity.
The average rate of population for all ancient civilizations appears to start around 1 person per hectare of land. By 1900 the average globally is about 5. By the 20th century there were about 25 people per hectare of land in Egypt, 12 in China, and 3 in Europe.
Reconstruction of food intakes by poor English and Welsh laborers found that between 1787 and 1796 they consumed, on average, 8.3kg of meat per year. The average American today eats about 97 kg.
According to an ancient Chinese proverb, the things that people cannot do without on a daily basis include the following: firewood, rice, oil, salt, sauce, vinegar, and tea.
In Eastern Prussia, as late as 1847, a third of the rural population could not afford bread.
Animals simply walking in circles was perhaps the most widespread form of power production until about the mid-19th century.
The power generation of a typical 18th century dutch windmill was about 7.5 watts. Wind turbines manufactured today have power ratings ranging from 250 watts to 7 MW.
At the beginning of the 18th century about 85% of Massachusetts was covered in trees; by 1870, only 30%. Today, it is 62%.
In premodern China millets, wheat, rice and corn supplied more than four-fifths of all food energy. India was basically identical.
Mesopotamian diets were short on Vitamin A and Vitamin C, and ancient inscriptions apparently make reference to blindness and scurvy. They ate a diet incredibly high in barley, which was very high-yielding, but lacked these key nutrients.
By 1917 the British Army relied on over 300,000 horses. Even in World War II, the Wehrmacht mobilized 625,000 horses for its invasion of Russia.
According to Phillip Paul, one of Napoleon’s generals and notable chronicler of his failed invasion of Russia, part of the provisions Prussia provided to the advancing French army included two million bottles of beer.
In 1800 the entire world economy consumed about 20 EJ (exajoules—energy equal to 1018 joules), 98% of which was from burning phytomass (so wood or charcoal). This is equivalent to less than 500 metric tonnes of crude oil. By 1900, energy supply had more than doubled to about 43 EJ, and half of it was now derived from fossil fuels, mostly coal. Between 1971 and 2019 world total energy supply increased from 230 EJ to 606 EJ.
Watt’s improved steam engine of the late 19th century had a capacity of just over 1KW. By 1900, the largest steam engine had a capacity 30x that—3 MW.
The two common impressions—that the 20th century was dominated by oil and the 19th dominated by coal—are both wrong. Wood remained the most important fuel before 1900 and, taken as a whole, the 20th century was dominated by coal.
The first oil tanker (1886) carried just 2300 gross tonnes. By the early 1920s the maximum size came to about 20,000 deadweight tonnes (dwt). The world’s largest oil tanker — the Seawise Giant—was built in 1979 and carried 564,763 dwt before it was eventually retired around 2010.
Brief interruptions in electricity provision can be expensive. In the US, every hour of lost power amounts to a loss of approximately $10m.
About 1/5th of all crop residues are still burned as a fuel source, mostly in low-income countries.
No other energy use offers as much of a payback as higher crops yields resulting from the use of synthetic nitrogen. By spending roughly 1% of global energy, it is possible to supply about half of the nutrients used annually by the world’s crops.
About 40% of the current global food supply depends on the Haber-Bosch ammonia synthesis process—a process that converts atmospheric nitrogen to ammonia by a reaction with hydrogen using a metal catalyst under high temperatures and pressures. Synthetic nitrogen provides about 70% of all nitrogen inputs in China. In its absence, diets in China would sink to a semi-starvation level. “A whole generation of citizens thought that the carrying capacity of the earth was proportional to the amount of land under cultivation and that higher efficiencies in using the energy of the sun had arrived. This is a sad hoax, for industrial man no longer eats potatoes made from solar energy, now he eats potatoes partly made of oil” (Howard Odum, 1971).
Food supply in affluent countries is now about 75% higher than the actual need according to basic macronutrient requirements, resulting in food waste of 30%-40% of all food sold.
Horse’s leg anatomy virtually eliminates the energy costs of standing. All other mammals need about 10% more energy to stand as they do to lie down.
The Middle Ages was certainly not a period known for technical innovation. Perhaps the most important however was the adoption of the collar harness for draft horses.
Calculations based on Han dynasty records show that during the fourth century BCE in the state of Wei a typical peasant was expected to provide five family members with nearly half a kilogram of grain per day.
The world’s heaviest column —the 605 tonnes of Red Finnish granite erected to commemorate Russia’s victory over Napolean—relied on 1700 men simultaneously pulling the column into an erect position.
Candles convert only about .01% of their chemical energy into light.