Energy
Technology invariably involves the manipulation of materials. Its advances have afforded endeavors at scales both large and small; but tinkering the tiny has been the most impressive.
The ability to build the monstrosities of modern architecture pales in comparison to bending molecules to human will. In coherently channeling electrons, computers take this miniaturization to the subatomic level. Yet materiality is an aside to what the most critical technology actually does, and that is to provide energy.
The earliest technologies, from the Stone Age to the establishment of settlements, aimed at the most intimate energy: food. Controlling fire played a crucial role in human descent.
Fire Pistons
A fire piston starts with handheld straw-like cylinder sealed at one end and open at the other. The cylinder is fitted with a piston that makes an airtight seal.
Pushing the piston compresses the air within. Quickly ramming the piston down into the cylinder generates enough heat to set a tiny bit of tinder within ablaze. That ember can then be dropped onto kindling to start a fire, assisted by some wind to encourage a flame.
Fire pistons were used prehistorically in southeast Asia. Application of the concept was reinvented many times.
The fire piston was patented in 1807 in both England and France by different men. This was after a public demonstration in 1802. So much for novelty in invention.
Fire syringes, as they were called, became popular household items in Europe during the early 19th century. They were supplanted by the safety match, which was invented in 1844, and was less safe than the fire piston. So much for truth in terminology.
The fire piston probably inspired German engineer Rudolph Diesel in his late-19th-century invention of the piston-based engine that bears his namesake. Fire pistons and diesel engines rely upon the same principle.
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An exclusive focus on food-energy slowly relented. Animal domestication offered beasts of burden as a supplement to human exertion. Then man turned his attention to controlling energy as a substitute for his own labor.
Early attempts worked with water, then wind. Both involved circular motion: waterwheels and windmills.
Rotary motion was ever the ultimate object of engines; at first for mechanical work, and then the generation of electricity: pure energy that can be transmitted over distance for a vast variety of local applications.
A turbine is a machine designed to capture energy from a moving fluid to put to work. 1 of 4 fluids is usually involved: water, wind, steam, or gas. Blades catch the moving fluid. These blades rotate about an axle, which drive a machine.
There are 2 types of turbines – impulse and reaction.
The blades of an impulse engine run around the axle and are usually bucket shaped. Waterwheels are an exemplary impulse engine.
In a reaction turbine, fluid flows past blades that face the end of the axle like flower petals. Windmills are reaction turbines.
Waterwheels were known in Roman times and changed little during the Middle Ages. Like windmills, their earliest use was in grinding grains, especially corn.
By the 10th century there were tens of thousands of waterwheels in England, engaged as a prime mover in various tasks, from pumping water to sawing wood, forging metal, fulling cloth, and operating bellows. This situation was typical throughout Europe, as population centers were near rivers which facilitated cargo transport.
The origin of windmills is obscure, but they seem to have evolved independently in Persia and northern Europe in the 7th century. The likely inspiration was sailing ships.
Heat Engines
A machine, receiving at distant times and from many hands new combinations and improvements, and becoming at last of signal benefit to mankind, may be compared to a rivulet swelled in its course by tributary streams, until it rolls along a majestic river, enriching, in its progress, provinces, and kingdoms. ~ English clergyman and educator John Stuart at the dawn of the 19th century
Fire returned to the forte with the concept of heat engines, which convert thermal energy into mechanical power. Heat engines were known from antiquity, but their utility as machines only came to the fore during the 19th century, when they powered the Industrial Revolution.
Steam Engines
As an amusement, Greek mathematician and engineer Hero of Alexandria made a simple bladeless radial steam turbine called an aeolipile in the 1st century CE.
The aeolipile was a vessel with pipes running into it, sitting in a basin of water which is heated, providing the steam source. The aeolipile had a stream release in the form of 2 nozzles (tipjets). When the vessel was pressurized, steam vented from the tipjets, generating thrust via the rocket principle, making the vessel rotate.
Italian engineer and architect Giovanni Branca described an impulse steam turbine in his 1629 book Le Machine. It bore no relation to later applications of steam power and was not much of an advance over the aeolipile. Branca’s turbine was one of many different mechanical inventions that he wrote of, some of which he himself had envisioned. English historian Alex Keller later commented that Branca’s book was of “armchair inventions which seldom ever had any 3-dimensional working counterparts.”
In 1678, Jean de Hautefeuille proposed using a piston in a heat engine powered by gunpowder. 2 years later, Christiaan Huygens and French inventor Denis Papin built a prototype.
Heat engines under steam power were first meaningfully employed for mining. As demand for coal and metals grew the desire to dig deeper grew stronger. Flooding from going below the water table was the chief obstacle.
English engineer Thomas Savery patented a steam pump in 1698 which he called “The Miner’s Friend.” A few were tried in the following decade, mostly in Cornish tin mines. They had several defects, among them a tendency to explode.
By trial-and-error tinkering English ironmonger and lay preacher Thomas Newcomen succeeded in making a workable steam pump in 1712. Newcomen had a business that specialized in designing, manufacturing, and peddling tools to the mining industry. Newcomen’s contraption combined innovations by Savery and Papin, who had created the steam digester, a forerunner of the pressure cooker.
Though by no means efficient or especially reliable, the Newcomen steam pump was commercially viable for 75 years, as was Savery’s less-expensive steam engine. Their use spread throughout Britain and continental Europe. Then these pumps were replaced by a superior steam engine, designed by Scottish mechanical engineer and chemist James Watt, who began studying steam engines in the early 1860s.
Watt concluded that Newcomen’s engine wasted 80% of the steam, as steam was used to heat the cylinder rather than providing motive force. Taking Newcomen’s engine as a baseline, Watt made numerous improvements in design and materials, resulting in his own steam engine in 1781. Watt’s tireless dedication resulted in technology that enabled the widespread use of stationary steam engines.
At the time, the power of steam engines was limited by low pressure, cylinder displacement, condenser capacity, and the rates of combustion and evaporation. Efficiency was constrained by the relatively low temperature differential on either side of a piston.
This meant that a Watt engine had to be quite sizable to produce a useful amount of power. They were therefore expensive to build and install.
As the 18th century unfolded the call was for higher pressures. Watt strongly resisted this. Watt mistrusted the materials technology of the day, especially boilers being able to withstand high pressure. So, Watt used his patent monopoly to prevent others from building high-pressure engines and using them in vehicles.
Watts’ reservations did not apply in the US, where his patent power did not reach. Several advocates of “strong steam” built high-pressure engines. One was American engineer and businessman Oliver Evans. A pioneer in cylindrical boilers, his radical designs were criticized by other engineers.
Evans did suffer several serious boiler explosions, validating Watts qualms. But Evans persisted, and introduced high-pressure steam engines to the riverboat trade on the Mississippi.
English mining engineer Richard Trevithick was the son of a mine captain. He grew up watching steam engines pump water from deep mines in Cornwall. In 1799, Trevithick was first to make a successful high-pressure steam engine. Unlike the more insouciant Evans, Trevithick worked incrementally: experimentally finding out what worked and what did not.
Trevithick had his first patent for a high-pressure steam engine in 1802, having built both stationary and vehicular engines.
Trevithick’s work was not without mishap. In 1803, one of his stationary pumping engines exploded, killing 4 men. Trevithick’s response was to incorporate safety valves and other measures to warn of impending danger.
American mechanical engineer George Henry Corliss developed a reliable stationary steam engine which he patented in 1849. His work became recognized as the greatest advance in steam power since Watt.
One of the final developments in stationary steam engines was running them at high speed: several hundred rpm (revolutions per minute), which was a necessity for electricity generation. As a turbine generates rotary motion, a turbine is particularly suited to drive an electrical generator.
In 1882, Swedish engineer Gustaf de Laval designed an impulse steam engine that subjected the turbine to severe centrifugal forces. This limited output due to the weakness of materials available at the time.
Appreciating the practical flaws in Laval’s turbine design, Anglo Irish engineer Charles Parsons invented the modern steam turbine in 1884. He immediately employed it to drive an electrical generator he had designed.
It seemed to me that moderate surface velocities and speeds of rotation were essential if the turbine motor was to receive general acceptance as a prime mover. I therefore decided to split up the fall in pressure of the steam into small fractional expansions over a large number of turbines in series, so that the velocity of the steam nowhere should be great. I was also anxious to avoid the well-known cutting action on metal of steam at high velocity. ~ Charles Parsons
Parsons’ steam turbine made plentiful, cheap electricity possible. It also revolutionized marine transport and naval warfare.
~85% of electricity generated worldwide today comes via steam turbines, including those powered by coal, geothermal, solar, gas, and atomic decay. The different energy inputs go to the same end: to boil water.
The energy conversion efficiency of modern steam turbine power plants is typically 33–45%: the rest of the energy leaves the power plant as waste heat.
Internal Combustion Engines
An internal combustion engine is an engine with working cylinders in which combustion occurs within the cylinders, providing mechanical power. Assorted designs of internal combustion engines were developed before the 19th century, but their commercial employment was hindered until petroleum became widely available in the mid-1850s. By the late 19th century internal combustion engines were employed in a variety of applications.
Internal combustion engines were patented as early as 1807, but none of these were commercially successful. The first such engine to succeed was by Belgian engineer Étienne Lenoir, who built a single-cylinder 2-stroke spark-ignition engine in 1858 that could be operated continuously. Lenoir’s engine differed from more modern 2-stroke engines in not compressing the charge before ignition.
Such a system had been invented in 1801 by French engineer Lebon d’Humberstein. It had a power stroke at each end of the cylinder, which worked quietly but also inefficiently. d’Humberstein was assassinated before he could work through the flaws in his patented design.
In 1861, French engineer Alphonse Beau de Rochas publicized his design for a 4-stroke engine, which he never built. Meanwhile, German engineer Nikolaus Otto built his first gasoline-powered engine the same year.
Otto tinkered away for decades. In 1876, he built a 4-stroke engine that efficiently burned fuel in a piston chamber. This process became known as the “Otto cycle.” It was the first practical alternative to the steam engine.
American engineer George Brayton developed a 2-stroke kerosene engine in 1873, but it was too large and slow to be commercially viable.
2-stroke engines complete a power cycle in 2 strokes of a piston – up and down – during a single crankshaft revolution. In contrast, a 4-stroke engine requires 4 strokes to complete a power cycle: 1) intake (for the air-fuel mixture), 2) compression (in a closed piston), 3) power (the engine delivers power to turn a crankshaft), and 4) exhaust (expelling the spent air-fuel mixture).
In a 2-stroke engine, the intake and exhaust functions simultaneously. 2-stroke engines have a higher power-to-weight ratio and fewer moving parts, so can be more compact and much lighter.
Scottish engineer Dugald Clerk designed the first successful 2-stroke engine in 1878. Although the form was simplified somewhat by English engineer Joseph Day in 1891, Clerk’s basic design remains in use today.
Owing to their power, low cost, and simple design, 2-stroke petrol engines were very popular throughout the 19th and 20th centuries in devices needing small engines, such as motorcycles, outboard motors, and chainsaws. But they emit more pollution. In the US, when the federal government mandated more stringent emissions, manufacturers switched to 4-stroke engines.
German engineer Gottlieb Daimler constructed the prototype of the modern gas engine in 1885. It was small and fast, with a vertical cylinder, using gasoline injected through a carburetor. A carburetor is a device for mixing air with vaporized fuel to produce a combustible or explosive mixture.
While others were contemporaneously working on their own automobile designs, German engineer and engine designer Karl Benz was first to patent an internal combustion engine automobile, in 1886. Benz patented his engine in 1879, and then patented the processes that made the internal combustion engine feasible for autos.
In 1889, Daimler introduced a 4-stroke engine with a much higher power-to-weight ratio. It had 2 cylinders arranged in a V, with mushroom-shaped valves. With the exception of an electric starter, most modern gasoline engines are descended from Daimler’s models.
A starter is an electric motor that initiates an internal combustion engine. The starter’s job is done once the engine starts. Before electric starting, internal combustion engines got going via a hand crank: a difficult and dangerous undertaking. Engines can be unpredictable during startup. An engine can kick back, causing sudden reverse rotation.
The first electric starter was installed in 1896 by its developer, English electrical engineer H.J. Dowsing. Starters became common in the early 1920s.
Rudolf Diesel developed his namesake compression-ignition engine in 1892. Fuel was injected at the end of compression and ignited by the high temperature created from the compression. Diesel demonstrated his engine at the 1900 World’s Fair using peanut oil for fuel.
Vehicles
Leonardo da Vinci pondered a self-propelled vehicle in the 15th century. The idea was thereafter vigorously pursued.
Steam-engine vehicles preceded those powered by petrol. A steam-engine automobile was built by French engineer Nicolas-Joseph Cugnot in 1769. Steam carriages had a heyday in Britain in the 1830s. By 1840 it was clear that steam coaches had a fleeting future. They had much to contend with, including public antipathy to machinery and the enmity of the horse-coach trade.
In Britain, the Locomotives on Highways Act of 1865 took the steam out of steam-powered transport: reducing permissible speeds and requiring 3-man crews for each vehicle. The act was repealed in 1896, having been in effect long enough to stifle the development of road transport in the British Isles.
The attitude toward automobiles was altogether different in the US. Americans were always gung-ho on innovation, with scant thought to externalities.
Methodist minister and physics professor J.W. Carhart built a working steam car in 1871 in Racine Wisconsin. This induced the State of Wisconsin to offer a $10,000 award to the first party to produce a practical substitute for animal transport (1875). The offer led to the first car race in the United States (1878).
Internal combustion engines also had numerous industrial applications, serving alternately to replace manual labor or to aid worker productivity. But getting folks to-and-fro became these engines’ primary employment.
Wings were strapped onto petrol engines in the early 20th century. For most of the century, air travel was a luxury reserved to the moneyed class. Deregulation that began in the US at the end of the 1970s changed that, letting everyman fly the skies like sardines in an airborne can.
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On modern energy, which is in the next chapter, on economics history.
