Creating the Twentieth Century

by Vaclav Smil

  The battle of the systems thus ended abruptly in 1890, although some accounts date it as expansively as 1886–1900. The latter delimitation is correct if one wants to include the period when AC became virtually the only choice for new central electric systems. And it must be also noted that, Edison’s reasoning (no matter if guided mainly by stubbornness or strategic cunning) aside, the battle had its vigorous British version as the DC side—led by two luminaries of the new electric era, R.E.B. Crompton and John Hopkinson—was joined by one of the world’s foremost physicists, Lord Kelvin. Sebastian Ziani de Ferranti, W. M. Mordey, and Sylvanus Thompson were the leading British experts behind HVAC.

  While in 1886 one could see the DC–AC competition as something of a standoff, by 1888 the choice was fundamentally over thanks to the rapid advances of three technical innovations that assured the future AC dominance: the already described invention of induction motors, commercialization of an accurate and inexpensive AC meter, and the introduction of the rotary converter. No more needs to be said about the advantages of electric motors. In April 1888, Westinghouse engineer Oliver Shallenberger designed the first reliable meter for AC, and the very next year Westinghouse Electric began to manufacture it. But as David (1991) points out, neither the AC motors nor the AC meters could have dislodged the entrenched DC systems (by 1891 they accounted for more than half of all urban lighting in the United States) without the invention of rotary converter that made it possible to connect old DC central stations, as well as already fairly extensive DC transmission networks, to new long-distance HVAC transmission lines.

  The first rotary converter was patented in 1888 by another of Edison’s former employees, Charles S. Bradley. The device combined an AC induction motor with a DC dynamo to convert HVAC to low-voltage DC suitable for distribution to final users. When the original single-phase AC systems began to be replaced by more efficient polyphase transmission, new converters were eventually developed to take care of that transposition, and its reverse proved very useful during the 1890s when it made possible to use the existing DC-generating equipment to transmit polyphase HVAC over much larger areas than could be ever reached by a DC network. And so really the only matter that was unclear by 1890 was how fast will the AC systems progress, how soon would the superior polyphase AC generation and its high-voltage distribution become the industry standard.

  A few bold projects accelerated this inevitable transition. The first one was the already mentioned Deptford station planned by the London Electric Supply Corporation, a new company registered in 1887, to provide reliable electricity supply to central London (figure 2.22). The site, about 11 km from the downtown on the south bank of the Thames, was chosen due to its location on the river and easy access to coal shipments by barges. Sebastian Ziani de Ferranti (1864–1930), the company’s young chief electrical engineer, conceived the station on an unprecedented scale. Large steam engines were to drive record-size dynamos whose shafts, weighing almost 70 t, were the largest steel castings ever made in Scotland (Anonymous 1889b). Because of the magnitude of the service (more than 200,000 lights) and the plant’s distance from the main load area in the downtown, Ferranti decided to use the unprecedented voltage of 10 kV. The company’s financial difficulties eventually led to his dismissal from the project’s leadership in 1891 and to the scaling-down of the Deptford operation, but Ferranti’s unequivocal conviction about the superiority of high voltage was fully vindicated.

  America’s first AC transmission over a longer distance took place in 1890, when Willamette Falls in Oregon was linked by a 20-km, 3.3-kV line with Portland, where the current was stepped down first to 1.1 kV and then 100 and 500 V for distribution (MacLaren 1943). A more decisive demonstration of inherent advantages of long-distance HVAC transmission took place at the Frankfurt Electrotechnical Exhibition in 1891 (Beauchamp 1997). Oscar Muller built a 177-km-long line to a generator at Lauffen on the upper Neckar River in order to transmit 149 kW of three-phase AC, initially at 15 kV. The first small three-phase system in the United States was installed by the newly organized General Electric in 1893 in Concord, New Hampshire, and there is no doubt that the tide was completely turned when Westinghouse Co. and General Electric made designs for the world’s largest AC project at the Niagara Falls (Hunter and Bryant 1991; Passer 1953).

  FIGURE 2.22. Massive exterior of London Electric Supply Corporation’s Deptford station and one of its record-size Ferranti-designed dynamos under construction. Reproduced from The Illustrated London News, October 16, 1889.

  On August 26, 1895, some of the water was diverted to two 3.7-MW turbines to generate electricity at 2.2 kV and use it at nearby plants for electrochemical production of aluminum and carborundum. In 1896, part of the output was stepped up to 11 kV and transmitted more than 30 km to Buffalo for lighting and streetcars. By 1900, 10 of Westinghouse two-phase 25-Hz generators of the first powerhouse (total of 37.3 MW) were in operation, and General Electric built 11 more units (total of 40.9 MW) for the second Niagara station completed by 1904. The project’s aggregate rating of 78.2 MW accounted for 20% of the country’s installed generating capacity (figure 2.23). Successful completion of the Niagara project confirmed the concept of large-scale HVAC generation and transmission as the basic paradigm of future electric systems.

  General Electric’s thrust into polyphase AC systems was greatly helped by insights and discoveries of Charles Proteus Steinmetz (1865–1923). Steinmetz was a brilliant mathematician and engineer who emigrated from Germany to New York in 1889, where he worked first for Rudolf Eickemeyer’s company and was hired from there in 1893 by GE (Kline 1992). Steinmetz’s work ranged from finding practical solutions to high transmission losses (his first patents at GE) to highly theoretical mathematical techniques used to analyze AC circuits with complex numbers. Between 1891 and 1923, he received more than 100 AC-related patents and published a dozen books. After 1900, Steinmetz had a critical role in setting up a new science-based laboratory at GE (one of the precursors of large-scale corporate R&D institutions) and guiding its early progress.

  FIGURE 2.23. Generator hall of Niagara Falls power plant. Reproduced from Scientific American, January 25, 1896.

  After the mid-1890s, it was only a matter of time before all of the necessary technical capabilities were put in place to support the expected expansion of AC systems. Parsons built the world’s first three-phase turbo-alternator in 1900 for the Acton Hall Colliery in Yorkshire, where the 150 kW machine was to energize coal-cutting machinery. The first public supply of the three-phase current (at 6.6 kV and 40 Hz) came from the Neptune Bank station (still powered by steam engines) that was officially opened Lord Kelvin, the former opponent of AC, in 1901 (Electricity Council 1973). But long after the dominance of AC was assured, the commonly observed inertia of complex techniques made DC linger. In the United Kingdom, DC still had 40% of all generating capacity in 1906 (Fleming 1911). In the United States, DC’s share in the total end-use capacity was 53% in 1902 and still 26% by 1917 (David 1991).

  The trend toward increasing transmission voltages that was set during the first decade of AC developments continued, albeit at a slower pace, for nearly 100 years. Highest American ratings rose from 4 kV during the late 1880s to 60 kV by 1900 and to 150 kV in 1913; the first 300 kV lines were installed in 1934, and by the 1970s AC was transmitted by lines of 765 kV (Smil 1991). By the 1980s HVAC interconnections tied together most of the European continent as well as the eastern and western part of the United States and Canada, while east—west links across the continent remained very weak. And by the early 1970s, transmission techniques made a full circle by returning to DC, but this time at high voltages (HVDC).

  HVDC, made possible by the use of mercury arc rectifiers that convert AC to DC and then reconvert it back to AC for distribution, was pioneered in Canada to transfer large blocks of electricity from hydro-projects in northern regions of Manitoba, British Columbia, and Quebec (Arrillaga 1983). This option becomes viable as soon as the cost of this conversion eq
uipment is appreciably less than the money saved by building a cheaper two-conductor DC line. HVDC has been also used in submarine transmission cables, first pioneered on a smaller scale in 1913 when the British Columbia mainland was connected with Vancouver Island. In 1954 came the first large-scale application when the Sweden—Gotland cable carried 20 MW at 100 kV over 96 km, but a decade later New Zealand’s two islands were connected in 1965 by a 250-kV tie that carries 600 MW.

  Expanding Generation and Consumption

  Proliferation of electric supply was very rapid: already in 1890 the United States had some 1,000 central electric systems and many more isolated generation units (Hunter and Bryant 1991). Many companies owned more than one station, and their service areas kept expanding. The Edison Electric Illumination Co. of New York, whose northernmost service boundary in 1883 was Nassau Street, reached 59th Street by 1890 and 95th Street by 1998, and by 1912 it served practically every street in Manhattan and the Bronx (Martin 1922). In terms of 50-W lightbulb equivalents, its connections rose from 3,144 lights on December 1, 1882, to nearly 1.5 million lights by 1900 and to more than 12 million by the end of 1913. By 1900, every major city in Europe and North America, and many on other continents, had various systems of public electric supply from central stations. This electricity was used initially for lighting and transportation and soon also for a variety of household and industrial tasks (Wordingham 1901; Gay and Yeaman 1906).

  During the first decade of the 20th century, many of these large cities were the first places where small stations that were located in or near downtowns or other densely populated areas were shut down and new, larger plants were built either on the outskirts of urban areas or directly in such coal-producing districts as the Midlands and Yorkshire in England and the Ruhr in Germany. In 1904 the Newcastle upon Tyne Electric Supply Co. commissioned its Carville station, whose design set the basic pattern for all subsequent large generating stations (Electricity Council 1973). The initial version had two 3.5-MW and two 1.5-MW units (combinations of boilers, turbines, and alternators that became later known as a turbogenerator) operated from a control room.

  Large generating stations, mostly at mine-mouth locations when coal fired, have remained a preferred choice for Western utilities ever since. Plants of increasingly larger capacities were built until the 1960s in the United Kingdom, primarily in the Midlands, and in the United States concentrated in Pennsylvania, Ohio River Valley, and the Tennessee Valley Authority region. All of these stations burn finely pulverized coal that is blown into their boilers in order to maximize combustion efficiency. The first experiments with this technique began at the Willesden station in England in 1903. By 1914 the use of powdered coal was developed into a successful commercial practice (Holmes 1914), but most electricity-generating plants adopted it only after WWI.

  The two pre-WWI generations also set the course for the construction of large-scale water power projects thanks to the introduction of two new turbines that eventually came to dominate hydroelectric generation. Several new water turbine designs appeared during the two decades after Benoit Fourneyron built his first reaction turbines during the late 1820s and the 1830s (Smith 1980). The most successful design was the one patented first in the United States in 1838 by Samuel B. Howd and then improved and commercially deployed by James B. Francis (1815–1892). This machine is known as the Francis turbine, but it is clearly a product of multiple contributions (Hunter 1979). Originally it had an inward flow, but during the 1860s it was developed into a mixed-flow turbine. During the 1880s Lester Allen Pelton (1829–1908) developed and patented an impulse turbine driven by water jets discharged into peripheral buckets, a design for very high water heads. In contrast, in 1913 Viktor Kaplan patented a reaction turbine with adjustable vertical-flow propellers that has become a preferred choice for low dams.

  Before WWI more than 500 hydroelectric stations were in operation around the world (mostly in Europe and in North America), and the world’s first pumped storage stations were also built. These stations use electricity produced during low-demand periods (mostly during the night) to pump water into a nearby high-lying reservoir, where it is available to be released into downpipes and converted almost instantly into hydroelectricity during periods of peak demand; a century later this is still the most economical way of an indirect electricity storage. But the period of hydroelectric megaprojects—exemplified in the United States by the Tennessee Valley Authority and by the Hoover and Grand Coulee dams—came only during the 1930s (ICOLD 1998).

  Expanding availability of electricity led almost immediately to applications beyond household and street lighting. Few facts illustrate the rapid pace of post-1879 developments than the frequency of major national and international exhibitions that were devoted exclusively to that newly useful form of energy or where electricity played a major part (Beauchamp 1997). Of 38 international expositions that took place during the exceptionally inventive 1880s, seven were devoted solely to electricity, including the already noted Paris Electrical Exhibition of 1881 and similar displays in London in the same year, Munich (1882), Vienna (1883), and Philadelphia (1884). Electricity was a major attraction at British Jubilee Exhibitions in 1886–1887 and even more so at Chicago Columbian World Fair in 1893 (Bancroft 1893).

  But already in Paris in 1881 several exhibitors showed, still as a curiosity rather than as a commercial proposition, sewing machines, lathes, and a printing press powered by electric motors. By 1890 General Electric was selling electric irons, fans, and an electric rapid cooking apparatus that could boil a pint of water in 12 minutes (Electricity Council 1973). Household appliances were introduced to the British market during the Crystal Palace Electrical Exhibition in 1891, and they included irons, cookers, and electric fires with the heating panels set behind wrought-iron screens. Two years later many more of these gadgets—including hot plates, fans, bells, bed warmers, radiators, and a complete Model Electric Kitchen with a small range, saucepan, water heater, broiler, and kettle—were featured at Chicago exhibition (Bancroft 1893; Giedion 1948). Early electric ranges resembled the well-established gas appliances, and the first toaster had only one set of resistance wires (figure 2.24).

  Chicago displays also contained an enormous array of industrial applications of electricity ranging from ovens and furnaces to metal- and woodworking machines (lathes, drills, presses) and from railway signaling equipment to an electric chair. Among the notable pre-WWI commercial introductions, I should at least mention (with the dates of initial appearance in the United States) the electric washing machine (1907, featured soon afterward in the Sears & Roebuck Co.’s catalog), vacuum cleaners (originally called electric suction sweepers), and electric refrigerators (1912). Willis Haviland Carrier (1876–1950) designed his first air conditioning system in 1902 after he realized that air could be dried by saturating it with chilled water in order to induce condensation. His first working system, with the cooling capacity of nearly 50 t of ice a day, was installed to control temperature and humidity for Brooklyn printing company Sackett-Williams. These controls eliminated slight fluctuations in the dimensions of their printing paper that caused misalignment of colored inks (Ingels 1952).

  FIGURE 2.24. Frank Shailor’s “electric heater,” the first practical toaster whose U.S. Patent 950,058 was assigned to GE, which began its production in 1909. Its construction was made possible by a new nickel-chromium alloy; Shailor used John Dempster’s (U.S. Patent 901,428) combination of 62% Ni, 20% Fe, 13% Cr, and 5% Mn for resistance wires.

  Carrier’s first patent (U.S. Patent 808,897) for the “Apparatus for Treating Air” was granted in 1906, and in 1911 he completed Rational Psychrometric Formulae, which has become a lasting foundation of basic calculations required to design efficient air conditioning systems (ASHRAE 2001). Textile, film, and food processing industries were among the first commercial users of air conditioning, while the cooling for human comfort began only during the 1920s with department stores and movie theaters. The first air-conditioned Ame
rican car was engineered in 1938, and in the same year Philco-York marketed the first successful model of a window air conditioner (NAE 2000). Widespread use of household air conditioning, and with it the large-scale migration to a suddenly comfortable Sunbelt, had to wait until the 1960s. By the end of the 20th century almost 70% of all U.S. households had either central or window air conditioning, and central units were being installed in virtually all new custom-built U.S. houses, regardless of their location.

  While mechanical refrigeration for commercial operations (cold storages, ice making, meatpacking, dairies, breweries) was perfected during the 1880s, its large equipment, the need for manual operation by skilled personnel, and the use of potentially dangerous ammonia as the refrigerant did not make the technique readily transferable to household use. The first practical design for a kitchen unit, patented by Fred Wolf in 1913, used self-contained copper tubing with flared joints to reduce the risk of leaks—and it even produced ice cubes (Nagengast 2000). But the first affordable household refrigerator, General Motor’s Frigidaire, became a common possession only during the late 1920s. Cost of refrigeration fell, and its safety rose, with the replacement of dangerous refrigerants by chlorofluorocarbons in 1931 (NAE 2000). But during the 1980s these gases were incontrovertibly implicated in the destruction of stratospheric ozone. Genesis, and solution, of this environmental concern will be covered in this book’s companion volume. By the year 2000, only color televisions rivaled refrigerators as virtually universal household possessions in affluent countries.