Energy - Vaclav Smil  ## Metadata - Author: **Vaclav Smil** - Full Title: Energy - Category: #books ## Highlights - Joule used very sensitive thermometers to measure the temperature of water being churned by an assembly of revolving vanes driven by descending weights: this arrangement made it possible to measure fairly accurately the mechanical energy invested in the churning process. In 1847 Joule’s painstaking experiments yielded a result that turned out be within less than one per cent of the actual value. The law of conservation of energy – that energy can be neither created nor destroyed – is now commonly known as the first law of thermodynamics. ([View Highlight](https://read.readwise.io/read/01jnbnnde34z0pvt0066e4q8bd)) - Clausius also crisply formulated the second law of thermodynamics: entropy of the universe tends to maximum. In practical terms this means that in a closed system (one without any external supply of energy) the availability of useful energy can only decline. A lump of coal is a high-quality, highly ordered (low entropy) form of energy; its combustion will produce heat, a dispersed, low-quality, disordered (high entropy) form of energy. The sequence is irreversible: diffused heat (and emitted combustion gases) cannot be ever reconstituted as a lump of coal. Heat thus occupies a unique position in the hierarchy of energies: all other forms of energy can be completely converted to it, but its conversion into other forms can be never complete, as only a portion of the initial input ends up in the new form. ([View Highlight](https://read.readwise.io/read/01jnbnvv0hh3hvvc3k98gcqyqz)) - Despite its supposed universality, the second law appears to be constantly violated by living organisms, whose conception and growth (as individuals) and whose evolution (as species and ecosystems) produces distinctly more ordered, more complex forms of life. But there is really no conflict: the second law applies only to closed systems under thermodynamic equilibrium. The Earth’s biosphere is an open system, which incessantly imports solar energy and uses its photosynthetic conversion to new plant mass as the foundation for greater order and organization (a reduction of entropy). ([View Highlight](https://read.readwise.io/read/01jnbntctt2sbemq4mh0jwe41z)) ## New highlights added March 2, 2025 at 1:36 PM - A weaker circulation is also set off by the outflow of cold polar air that eventually warms up, rises, and returns at higher altitudes to close the loop. You can visualize the mid-latitude (35°–50°) circulation (the Ferrell cell) as a billiard ball sitting atop two rotating balls: if both rotate clockwise, the upper ball must rotate anti-clockwise (but in reality it does not complete the loop) ([View Highlight](https://read.readwise.io/read/01jncak13621bt141gy8h33wxs)) - Water’s high specific heat capacity, 4.185 J/g C, is several times that of soil and rock, and that is why the temperature of water rises and falls more slowly than that of solid surfaces and why it retains much more heat per unit of volume, making the ocean the world’s most massive temperature regulator. An Earth covered mostly by continents would repeatedly swing between high and low temperatures (similar to the oscillations experienced in large deserts). ([View Highlight](https://read.readwise.io/read/01jncatxbmbb5zastxdt2w0fwe)) - There are two sources of this internal energy: the basal heat from the slow cooling of the Earth’s molten metallic (largely iron) core and that from radioactive decay (particularly of uranium 235 and 238, thorium 232, and potassium 40). The latter flux is more important, and while the definite partitioning of the heat’s origins is still impossible, we have plenty of measurements to enable us to conclude that the aggregate global power of this geothermal energy amounts to some 44 TW. ([View Highlight](https://read.readwise.io/read/01jncbb1vj2mmws9wekn1eaeez)) - About sixty per cent of the Earth’s heat is converted into the formation of new sea floor along some 55,000 km of the ocean ridges, which divide the Earth’s crust (its thin, solid, topmost layer) into rigid and slowly moving geotectonic plates ([View Highlight](https://read.readwise.io/read/01jncbem6n1hv2c4ewfbpek18f)) - This continuous recycling explains why there is no ocean floor older than about 200 million years (most of it is younger than 100 million years) and why the most violent earthquakes (often causing massive tsunami) and volcanic eruptions are concentrated along the subduction fronts. ([View Highlight](https://read.readwise.io/read/01jncbg7m0zb6ab9njrf3exhma)) - Photosynthesis is energized by the absorption of light by pigments in the thylakoid membranes inside bacterial and plant chloroplasts (the cellular organelles that give plants their green color). The energy efficiency of the conversion of simple inorganic inputs into new phytomass is surprisingly low. Introductory textbooks often outline the entire process in a simple equation in which the reaction of six molecules of CO2 and six molecules of water produces one molecule of glucose and six molecules of oxygen: 6CO2 + 6H2O = C6H12O6 + 6O2. The reality is vastly more complex. The key sequential steps were revealed for the first time in 1948 by Melvin Calvin (1911–1997) and his co-workers (Calvin received the 1961 Nobel Prize for Chemistry for this discovery). Most importantly, the process entails not only carbon fixation and oxygen evolution, but is also the complex exchange of oxygen and CO2 in two, closely related, cycles (the other being photorespiration). ([View Highlight](https://read.readwise.io/read/01jncbhx50bjew76tc2ydvhjay)) - Unfortunately, most widely cultivated staples, as well as most vegetable and fruit species, use the C3/C2 cycle, giving the so-called C3 plants (which include rice, wheat, barley, rye, all tubers, all leguminous grains, and all oil crops) inherently low energy conversion efficiencies. Their cultivation also demands a great deal of water. ([View Highlight](https://read.readwise.io/read/01jncbw4beds5ft3629nsmbn95)) - The maximum theoretical net efficiency of photosynthesis (after subtracting all respiration losses) is about four per cent of insolation, but this rate can be approached only during brief periods and in the presence of adequate water and nutrients. Intensively tended (irrigated, fertilized) crops can average two per cent efficiency during their growing season; the most productive temperate and tropical forests approach 1.5%. The global continental average is only 0.33%, and, because oceanic phytoplankton convert less than 0.1% of insolation into new aquatic phytomass, the average for the entire biosphere is less than 0.2%. To put it differently, the energy of only one in 500 photons which reach the planet’s ice-free surface gets converted into new phytomass. ([View Highlight](https://read.readwise.io/read/01jncc1cbpe1yx17rb53r5zn8v)) ## New highlights added March 6, 2025 at 6:22 AM - Like coal, crude oil has been known since antiquity. There were many locations (particularly in the Middle East) where oil seeps, pools, and tar ponds indicated its subterranean presence but its only documented use was for heating the (late) Roman baths in Asia Minor. Modern extraction of crude oil was stimulated by the search for a cheaper illuminant to replace the expensive, and increasingly scarce, oil rendered from the blubber of sperm whales, a perilous pursuit that was immortalized in Herman Melville’s (1819–1891) masterpiece, *Moby Dick.* ([View Highlight](https://read.readwise.io/read/01jnnwejpac2ba6h6rcve8psra)) ## New highlights added March 7, 2025 at 9:50 PM - We have three choices if we wish to keep on increasing energy consumption while minimizing the risks of anthropogenic climate change (due mostly to rising combustion of fossil fuels) and keeping atmospheric levels of greenhouse gases from rising to as much as three times their pre-industrial level: we can continue burning fossil fuels but deploy effective methods of sequestering the generated greenhouse gases, we can revive the nuclear option, or we can turn increasingly to renewable energy. None of these options is yet ready for large-scale commercial adoption, none could be the sole solution, and all have their share of economic, social, and environmental problems. ([View Highlight](https://read.readwise.io/read/01jnt3fxyvx47j21cw73fta7xw)) - Despite of a great deal of theoretical research, and much interest shown by industries and governments, CO2 sequestration is only in the very early experimental stages; its eventual contribution to the management of the global warming challenge is uncertain. In contrast, we have half a century of experience of large-scale commercial generation of nuclear electricity, which has shown us what to avoid and what techniques to favor. The general expert consensus is that any development of the nuclear industry cannot be a replica of the first generation; there has been no shortage of new, ingenious designs aimed at minimizing or eliminating the concerns that contributed to the stagnation (and in some countries even retreat) of nuclear electricity generation. Several, so-called, inherently safe nuclear reactor designs provide passive guarantees of fail-proof performance: even operator error could not (as it did in Chornobyl) lead to a core meltdown. ([View Highlight](https://read.readwise.io/read/01jnt3j8nmd7m8cpt81k0pn0rm)) - . Increased concerns about the possibility of terrorist attacks in the post-9/11 world are a powerful counter-argument to substantial expansion of nuclear generation. But the future of the industry will not depend primarily either on better designs (they have been available since the mid-1980s), or on the fears of a terrorist attack (there are already hundreds of reactors in operation, and many other high-profile targets). What has to change is the public acceptance of this, potentially risky, but very rewarding, form of electricity generation, and I have argued that there is little chance of any substantial worldwide return to nuclear generation unless led by the world’s largest economy. ([View Highlight](https://read.readwise.io/read/01jnt3mc1cracsfm2ee7ha3krf))