Frank Shuman’s Solar Arabian Dream
On a clear, blazing hot day in June of 1913, the cream of British colonial society in Egypt—including journalists, ranking civil servants, and diplomats—gathered in Maadi, a small farming village on the banks of the Nile several miles south of Cairo, for the grand opening of a most unusual irrigation plant. Sipping champagne and snacking on cheese and caviar, mustachioed men in Panama hats and pith helmets and elegant ladies carrying parasols strolled the grounds, marveling at the long, gleaming rows of trough-shaped mirrors concentrating sunlight onto cast-iron boilers running the length of each trough. Heated to just more than 200 degrees Fahrenheit, water in the boilers turned to low-pressure steam to drive a specially designed, 75 horsepower engine. As if by magic, running on nothing more than sunlight, the engine pumped thousands of gallons of water from the Nile, saturating the arid landscape.
Among the distinguished, well-dressed crowd, two men stood out. The most dazzling by far was Viscount Horatio Herbert Kitchener of Khartoum, a military hero famous for bringing Sudan under British control in the 1890s. Tall, with a thick walrus mustache and piercing eyes, Kitchener had accepted an appointment two years earlier, in 1911, as consul-general and minister plenipotentiary in Egypt, making him the most powerful man in the country. Valued for its proximity to the Suez Canal, Egypt was a prize colonial possession, but not one easily managed. To quell nationalist stirrings and bring Egypt more firmly under British control, Kitchener, trained as a military engineer, set about improving the country’s economy, first by strengthening its infrastructure. Chief among his goals was increasing the yield of Egypt’s valuable cotton crop—an initiative requiring drastic improvement in the country’s primitive irrigation system consisting mainly manpower and crude canals. Finding a way to pump water from the Nile to faraway cotton fields without spending a fortune on coal-powered irrigation pumps was high on Kitchener’s list.
An intriguing solution was provided by Kitchener’s host that hot July day—American inventor, engineer, and solar energy pioneer Frank Shuman. A dead ringer for Teddy Roosevelt, Shuman shared much of the former U.S. president’s energy and force of personality. Earlier success with his invention of “Safetee-Glass”—shatter-proof glass used for skylights, car windshields, goggles and machine tool guards—had made Shuman a wealthy man, freeing him to pursue his engineering passions in his Edison-like inventor’s compound in Philadelphia. Like many leading scientific minds of the early decades of the 20th century, Shuman feared that the industrialized world’s rapacious consumption of coal and, increasingly, oil, would soon result in drastic shortages of those finite fuels. And so, like Mouchot, Ericsson, and Eneas, all of whose work he knew well, Shuman began tinkering with solar motors in 1906. Well aware of Eneas’s all too public failure a few years earlier, Shuman set his sights on a simpler, sturdier, less-expensive design for a solar engine.
For inspiration he turned to the work of two of his colleagues, American engineers H.E. Willsie and John Boyle, who, building on the work of late 19th century French engineer Charles Tellier (the inventor of commercial refrigeration), were experimenting with low temperature solar motors—devices that used liquids with low boiling points, such as ammonia, to generate steam. The main advantage of the approach, for Shuman, was the simplicity of the technology, consisting mainly of rows of low-cost hotbox solar collectors fitted with pipes. After a year of lab experiments, in the summer of 1907 Shuman built a small-scale demonstration plant in his backyard in Tacony, a suburb of Philadelphia. To promote his solar motor and drum up interest among potential investors, Shuman circulated handbills throughout the city inviting the public to attend a demonstration of the sun machine “any clear afternoon between twelve and three p.m. during the next two weeks.” The exhibition had the precise effect Shuman was after. Large crowds flocked to see the strange device, consisting of more than 1000 square feet of low-lying hotbox collectors filled with a few inches of sun-heated water and laced with iron pipes containing ether, which has a relatively low boiling point. Vapor resulting from the solar-heated ether powered a 3 ½-horsepower steam engine used to pump a continuous stream of water. The motor ran so smoothly—and drew so much attention—that Shuman left it running throughout the fall and winter. Visitors in December and January were especially impressed to see the sun motor chugging along on sunny winter days, despite freezing temperatures and snow underfoot.
Encouraged by his initial success, Shuman set about improving the solar motor’s design and performance. His main challenge was to generate enough steam to power a larger, more impressive engine, and to that end Shuman made several significant changes. First, he replaced ether with water. Although ether was useful for its lower boiling point, its equally low center of gravity produced vaporous wisps instead of the dense clouds of steam necessary to generate larger amounts of horsepower. Water was a better bet. But using water necessitated turning up the heat. To that end, Shuman better insulated the collector boxes and added a lower pane of glass beneath the top pane with an inch of dead air in between. And despite his initial aversion to the sort of expensive, breakable reflectors used by Mouchot and Eneas, Shuman recognized the utility of adding concentrating mirrors to the design, fixing one square yard angled reflectors to the top and bottom end of each hotbox.
By 1910 Shuman was ready to put his new design to the test and build a commercial scale solar power plant. Taking up an entire half acre of Shuman’s compound, the plant was roughly 10 times the size of the original installation, consisting of 572 individual hotbox collectors arranged in 26 arrays mounted on frames to keep them off the damp ground. Including the mirrors, the total sun collection area was more than 10,000 square feet. Pipes at one end fed the arrays with water that, brought to a low boil by the concentrated sunlight, turned to wt steam channeled through pipes at the opposite end of each array. When the low-pressure steam arrived at the engine it entered a partial vacuum chamber that Shuman had designed to ramp up the motor’s power. Under normal conditions, water boils at 212 degrees Fahrenheit. But the lower the air pressure, the lower the boiling point of water (which is why water boils more readily at high elevations). In the vacuum chamber built into Shuman’s steam engine, water boiled at only 102 degrees Fahrenheit. When water heated by the collectors to just below its normal boiling point hit the vacuum chamber, it exploded into high-pressure, high-powered steam to drive a large turbine.
At its best, Shuman’s new and improved sun machine produced around 600 pounds of steam per hour, generating 25 horsepower—enough to pump 3000 gallons of water per minute to a height of 33 feet. Although this was paltry compared to industrial-sized, coal-powered steam engines that produced more than 100,000 hourly pounds of steam to drive a 3000-horsepower engine, it was an impressive accomplishment nonetheless. And it convinced Shuman that he was on the verge of a major breakthrough in commercial solar power. To compete with coal on more equal footing, he reasoned, a solar plant would need to be able to run an industrial sized, 1000-horsepower steam engine. To do so, Shuman calculated, would require approximately 160,000 feet, or four acres, of solar collecting area, at an upfront cost of around $40,000. Equally adept at promotion as he was at mechanical engineering, Shuman began talking up his plan to any deep-pocketed investor willing to listen. “One thing I feel sure of,” Shuman wrote in a letter published in Scientific American in 1914, “and that is that the human race must finally utilize direct sun power or revert to barbarism.” Backed by daily headlines predicting imminent shortages of coal and gasoline, he described an exciting solar future where far-flung deserts in remote corners of the world could be made to bloom with the aid of sun-powered irrigation. Shuman Within a few short decades, Shuman confidently predicted, solar energy would be a main source of power across the globe.
The Philadelphia investors who’d backed (and profited handsomely from) Shuman’s Safetee-Glass venture, though, were not nearly as sanguine about the prospects for solar power. Already heavily invested in Pennsylvania’s booming coal industry, Philadelphia money-men saw little to be gained by putting $40,000 into an alternative energy technology with such a history of commercial failure. Stymied at home, Shuman turned his sites across the Atlantic to London, where his colleague and consultant, British engineer A.S.E. Ackermann, had contacts in scientific and investment circles. For several weeks during the summer of 1911 Shuman hit the speaking circuit, making the rounds of London’s most prestigious scientific societies where he wowed audiences with idealistic visions of massive solar motors freeing the world from dependency on fossil fuels. On a more prosaic but equally persuasive note, Shuman reminded his listeners the solar power was not only visionary but also economically practical, especially in far-flung, hard-to-reach regions of the British Empire where the high cost of coal hindered development. Admired for his Teddy Roosevelt-like passion and Thomas Edison-like ingenuity, Shuman quickly became a celebrity among London’s intellectual and industrial elite, and investors began reaching into their pockets.
Meanwhile, as researchers funds began pouring in, Shuman and Ackermann got down to the business of ironing out important details, such as where to build the plant, and to what purpose. The ideal location, they reasoned, was one where the sun shone brightly year round, where coal had to be imported at considerable cost, and where there was need for steam-powered irrigation—the very task that Shuman’s model plant had performed so impressively in his backyard. Egypt fit the bill on all counts. Coal there was expensive, but land and labor were cheap. The copious, unrelenting sunshine that baked much of the land into desert was a source of free, constant solar fuel. Plus, the need for mechanized irrigation was paramount; without it, only lands adjacent to the Nile River were arable. And finally, Egypt was a constant source of worrisome headlines in the British press. Although invaluable for giving Britain control of the Suez Canal, Egypt was in many ways a backwater, lacking sewers, hospitals, doctors, and other basic amenities of modern civilization. Crushing national debt and resentment over British occupation spurred intermittent nationalist uprisings among Egyptian peasants, weakening the British Empire’s tenuous hold over one of its most valuable possessions. In short, the future of Britain’s presence in Egypt was a hot topic. Building a solar-powered irrigation plant there was sure to garner lots of attention and free publicity.
The final and perhaps most salient point in Egypt’s favor was the presence of Lord Kitchener, who Shuman and Ackermann rightly suspected would be intrigued by, and throw his considerable weight behind, the project. They were not disappointed. With Kitchener’s blessing, Shuman leased land in the farming village of Maadi—which was also the administrative center of Egypt and the location of Kitchener’s official residence—and prepared to have parts shipped from his compound in Philadelphia to Egypt. First, though, Shuman had to deal with an unwelcome intervention of the form of famed British physicist Sir Charles Vernon Boys, who’d been brought in as a consultant by Shuman’s British backers to evaluate Shuman’s schematics. To Shuman’s annoyance, Boys suggested a major change: replacing the hotbox collectors with trough-shaped parabolic mirrors. The advantage of the mirrors, Boys argued, was that they would concentrate sunlight on the boiler on all sides, thus producing heat and steam more efficiently. The disadvantage, Shuman countered, was that replacing cheap hotboxes with pricey mirrors would raise the cost of the plant well beyond the initial $40,000 estimate. After all, Shuman’s commercial strategy centered on building a solar plant that could compete with coal-fired plants in terms of both power and cost. Building the collectors with more expensive material without going over budget would mean including fewer collectors, thereby dramatically scaling back the plant’s power output from a robust 1000 horsepower to a comparatively measly 85.
Although Shuman firmly believed that the path to commercial success lay in demonstrating that a solar power plant could run an industrial-sized steam engine, he was forced to concede to Boys, whose opinions on matters scientific were taken as gospel in British engineering circles. And so, summoning the can-do American spirit for which he had become famous, Shuman forged ahead. Rather than build parts in Philadelphia and have them shipped to Egypt, as per the original plan, Shuman decided to build the plant from scratch in Maadi, using local materials.
As rows of trough-shaped mirrors began to appear in Maadi, word spread throughout Egypt and all the way back to England, where Shuman’s investors followed the plant’s progress. A few months later, the plant was complete. After years of honing his technical expertise and preaching the solar gospel, Shuman had in hand a technology he believed capable of convincing not only his financial backers and the editors of Scientific American but the entire world that solar power had arrived as a viable alternative to coal power. And on that June day in 1913, as the sun plant’s specially designed steam engine chugged into action, pumping thousands of gallons of water to dramatic effect, Shuman stood triumphant. Like the celebrated Wright brothers, who only a decade earlier had made real the seemingly impossible dream of human flight, Shuman had finally, is appeared, succeeded where all other solar visionaries had failed. Here, for the first time in history, was a commercial scale solar plant doing useful work previously impossible due to the high cost of coal.
Solar power truly seemed to have crossed a threshold, now standing on the brink of widespread commercial success. Lord Kitchener certainly thought so. Thrilled at having found a cost-effective way to upgrade Egypt’s irrigation system and increase the country’s lucrative cotton crop, Kitchener offered Shuman a 30,000- acre cotton plantation in British Sudan on which to build a much larger version of the solar plant. The German government, whose ambassador to Egypt was among those invited to the Maadi plant’s grand opening, awarded Shuman $200,000 in Deutschmarks to design and construct a solar-powered irrigation system in German-controlled African, in the southwest part of the continent. Flush with success, fame, and funds, Shuman envisioned solar power plants on vast scales, going so far as to begin sketching designs for a 20,000 square mile plant in the Sahara desert to generate 270 million horsepower—an amount, he noted, equal to all the fuel burned around the world in 1909.
Although Shuman had taken solar power further than any of his predecessors, the immediate future of solar power was ultimately at the mercy of forces far beyond his—or anyone’s—control. Soon after his success at Maadi, Shuman’s grand solar plans were scuttled by the most unlikely of sources—Franz Ferdinand, Archduke of Austria and Royal Prince of Hungary and Bohemia, whose assassination by a member of a secret Serbian military society in 1914 plunged Europe and, eventually, the United States into the first World War. Suddenly, solar power, which Shuman had made seem so vital to the future health of Western industry, fell to the wayside as England, France, Germany and other European powers mustered all available resources for the war effort. Engineers working at the Maadi plant, including Shuman, returned to their home countries and within several months the plant itself was dismantled for parts and scrap metal.
Although Shuman, in his 50s, was too old to fight, he was, in a sense, a casualty of the Great War. For nearly a decade he had poured all of his considerable energy and ingenuity into advancing the cause of solar power and hoped to resurrect solar-powered irrigation after the war. But as the first conflict almost entirely dependent on fossil fuel burning trucks, tanks, ships and airplanes, WWI helped to more firmly entrench not only coal but also oil as fuels indispensible to industry. Greater production of both fuels spurred by the war lowered costs, making it more difficult for solar technology to compete on equal economic footing. And when oil companies—including Britain’s Anglo-Persian Oil Company—discovered and began to harvest vast amounts of oil in the Middle East, South American, California and other hot, dry places where fossil fuels had once been scarce and expensive, solar energy appeared to lose its most alluring advantage. For all intents and purposes, the great age of 19th and early 20th century solar entrepreneurship and invention, an age dominated by Auguste Mouchot, John Ericsson, Aubrey Eneas, Frank Shuman, and other intrepid, idealistic inventors, had come to an end.