While working on an article on the history of early wind turbines, I tumbled down a very deep rabbit hole. How was Dimitri Stein able to work on wind energy in Berlin during the height of World War II? This was post Kristallnacht, and Stein lived and worked right under the nose of the Third Reich.
Stein led a remarkable life. Surviving the war in Nazi Germany was just one part of it. He died in 2018 at the age of 98 after a successful career in business, industry, and academia.
Stein, Wind, and the Third Reich
Yet it was his research on wind energy during the war years that intrigued me. I’ve written about other Germans developing wind turbines as part of the Nazi war machine’s plans for energy autarky or self sufficiency, so I have a keen interest in the subject. The Reich also wanted to use wind turbines to aid German settlement of the East once the local population had been exterminated.[1]
Son of Russian refugees from the Bolshevik revolution, Stein grew up in Berlin.[2] In 1938 he enrolled at TU-Berlin (today the Technischen Universität-Berlin) in a program leading to a doctorate in electrical engineering. This was well after the Reichstag fire of 1933, and before the disastrous invasion of the Soviet Union. The Nazi’s were at the peak of their power.
Stein received his engineering degree in 1942 and began work on his doctoral thesis. In the fall of 1943, he submitted his dissertation. The curt response he received from the Nazi party commissar was “half-breed, grade 1.” Stein’s father was Jewish.[3]
We can only imagine how Stein’s world must have come crashing down. Once an up-and-coming researcher, he was now a marked man.
In the spring of 1944, Stein fled the Gestapo with the aid of his faculty adviser, Alfred Dennhardt, hiding in lower Bavaria until the war’s end. This was at great risk to Dennhardt. The penalty for harboring a Jew was death.
Germans were much vaunted at the time for their efficiency and meticulous record keeping, no doubt due in part to Nazi propaganda that they were so. Nevertheless, Stein published extensively as a graduate student during the period from 1941 to 1944. And the topics he published on were of interest to the Nazi war effort. In other words, He wasn’t in hiding. He was quite visible. Yet he wasn’t picked up and sent to a camp.
The Nazi’s missed Stein, or overlooked him.
Stein was part of the Reich’s wind power working group or committee (Reichsarbeitsgemeinschaft Windkraft). As part of that group, Stein wrote reports on wind turbine development in Denmark, subsequently publishing them in an engineering journal. He also published an article on how wind turbines were being used in agriculture in the USSR.[4] Both countries were occupied by the Wehrmacht at the time. And as noted, the Third Reich had a program for German settlement of the “eastern lands” with the aid of wind energy.[5]
I have read translations of these reports that Stein published in German and could find no political content or perfunctory rhetoric designed to endear him to Nazi officialdom, though I haven’t seen the original German documents. This wasn’t always the case among those working with wind energy during the Third Reich.[6]
Until he was exposed by the local gauleiter, Stein must have led a charmed life.
But the end of the war is not the end of our story.
Nordwind and the Universal Windmotor
In 1946, Stein and others founded the company Nordwind near Holzminden in Niedersachsen (Lower Saxony) between Hannover and Göttingen. They developed what they called a Universal Windmotor that could be used to pump water or generate electricity by delivering power to ground level via a vertical shaft.
Meanwhile, an island in the Wattenmeer off the coast from Hamburg was in need of power. Neuwerk lies in the mud flats at the mouth of the Elbe River. It had used a combination of wind and diesel to power a few farm houses and an important light house. Both machines had failed at the end of the war and the local utility called for a replacement.
Nordwind won a contract in 1947 to install a wind turbine on the island. Franz Villinger led Nordwind’s design team and supervised installation of one of its Universal Windmotors in 1949.[7] By this time, Stein had emigrated to the United States where he eventually taught at North Dakota State University before moving to City College of New York. In New York City, Stein met his wife, a fellow Berlin ex-pat, and a simultaneous translator at the United Nations.
At 15 meters in diameter, Nordwind’s wind turbine was large for the day, sweeping almost twice as much area of the wind stream as the better known contemporary Allgaier wind turbine designed by Austrian aeronautical engineer Ulrich Hütter.
The Nordwind machine had several unique features by today’s standards. First, it drove a DC generator at ground level. Modern wind turbines generate electricity at the top of the tower in the nacelle. However, traditional European wind mills transmitted mechanical power through a vertical shaft for grinding grain. Similarly, early Danish wind turbines, such as that pioneered by Poul la Cour, the Danish Edison, and the commercial spin offs from his work also used a vertical shaft to drive a dynamo at ground level. And we know that Stein and the Reich working group had studied Danish design.
Nordwind’s three-blade, upwind rotor also closely resembles the appearance of Danish wind turbines that became common in the 1970s and 1980s. The planform or shape of the blades look quite similar.
In another striking parallel between the Nordwind blades and those of the modern Danish wind revival were the pitchable blade tips. The outer third of the Nordwind blades changed pitch to regulate power much like later Danish wind turbines of the 1970s and 1980s. Danish wind turbines evolved from those designed by Johannes Juul during the 1940s and 1950s.[8]
The Nordwind turbine also used a large fantail to orient the rotor into the wind. The fantail could also be used to mechanically turn the rotor out of the wind during storms. Fantails were a common feature of both Danish and German wind turbines well into the 1980s.
The question arises, who was influencing whom. Were Stein and Villinger influenced by Danish thinking at the time? After all, Stein had published a paper on Danish wind turbine design in 1942. Or had Juul based his wind turbine at Vester Egesborg in 1950 on Stein’s work or a conversation with Stein? Or was this simply common mill craft of the day?
The Nordwind turbine used two forms of speed control. The hub contained a centrifugal gearing system that pitched the outer third of the blades to maintain a relatively constant rotor speed to run the dynamo. The orientation fantail was also used to furl the rotor out of the wind in storm conditions.
Stein’s thesis was on speed regulation and his ideas would have likely played a part in how the Nordwind turbine’s rotor was regulated.[9]
In contrast to traditional millcraft, the Nordwind turbine was a “fast runner” or what we would call a high-speed turbine today. Villinger, the Nordwind engineer, reported that the turbine had a tip-speed ratio of 6. Stein, in a retrospective for IEEE’s in house publication on the Neuwerk turbine in 2009 wrote that its tip-speed ratio was 7.5.[10] Stein was 89 at the time.
Both are probably right as the Nordwind turbine was rated at two different wind speeds and it’s not a critical distinction.[11] In either case, Nordwind’s rotor speed was far superior to traditional European windmills and corresponds to the trend toward modern wind turbine design.
Nordwind didn’t exist long before it was absorbed by Allgaier who was marketing Hütter’s much more sophisticated wind turbine for similar applications: water pumping and electricity generation.
Hütter’s design used three slender blades downwind of the tower and a generator at the top of the nacelle, transmitting electricity to ground level. Electricity could be used to pump water with an electric motor or for any other purpose.[12]
During this period Nordwind had won a contract with Algeria, subsequently shipping five to the country where two were installed to pump water. The other three turbines were still in their crates when Algeria’s war for independence from France broke out.[13]
One of the Nordwind’s installed in Algeria was erected in an oasis at Adrar, some 1,500 km south of Oran in the midst of the Sahara Desert. The wind turbine was intended for an agricultural experiment station, now part of a local university. The turbine was intended to pump water from a 40 meter deep well for the oasis. Remarkably, despite revolution, war, and the ravages of time, the turbine was still standing in 2011 when researchers were planning to repair it. French historian Etienne Rogier has found a Youtube.com video showing the turbine and its components.[14]
Stein was active into his 90s and his published account of the Neuwerk turbine differs some from the historical record. Stein wrote that the turbine was installed in 1946. Matthias Heymann, in his history of German wind energy, found that the previous wind turbine on the island was destroyed in 1947, leading to the installation of the Nordwind turbine in 1949.[15] This makes sense with the data that Stein provides in his 2009 article showing the production of nearly 30,000 kWh in 1950 from the Nordwind turbine. If he had earlier data he would have provided it.
Stein also wrote that the turbine operated for twenty years. This is extremely unlikely for a one-off turbine at a windy remote site with untested technology by a company that didn’t last more than a few years. As it is, Stein himself wrote that the 1950 production didn’t include any generation in December because the turbine was out of service due to a bearing failure—not a good sign for any wind turbine’s longevity.
In an article in Die Welt, Stein claimed the turbine operated for 12 years until a cable was laid to the island in 1958. This is much more realistic. And most likely the turbine operated sporadically for eight years from 1950 to 1958.
Juul’s Gedser turbine operated commercially for eight years and it was the most commercially successful of the early post war wind turbines. So Stein’s Neuwerk turbine was as successful as any of the period though it has largely been forgotten.
TU-Berlin Makes Amends
Stein, was, as we say today, well connected both in the ex-pat community and in post war Germany and Russia. Stein likely spoke Russian as well as German. With his language skills and academic background, he launched another career as an American liaison with German manufacturers, universities, and research institutes as well as with Soviet industry.[16]
It was through these circles that he finally obtained his PhD. Oh his behalf, a friend approached TU-Berlin to redress the injustice done to Stein when they refused his thesis because his father was Jewish. Though his thesis had long since disappeared, the university accepted the paper Stein published summarizing his work in September 1943. After 65 years, TU-Berlin granted Dimitry Stein his doctorate in 2008 in an emotional ceremony.[17]
For me, the story comes full circle. In the mid-1990s, Klaus Kaiser approached me about hosting some of my articles at TU-Berlin. Kaiser was a doctoral student in the Aerospace Institute’s Department of Construction and Design and part of the university’s wind turbine work group (Arbeitsgruppe Windkraftanlagen). You could say that this group was the institutional descendent of the group of students that Stein contributed to in the 1940s. TU-Berlin hosted my articles on wind energy until 2003 when I created my own web site. I am grateful to TU-Berlin and their faculty for making this possible and I was proud to be a part of their work. It’s heartening that TU-Berlin made amends for their grave mistake in 1943.
What Might Have Been
We can only imagine what Stein might have done if his country had welcomed his contributions instead of persecuting him. Maybe he would have been able to continue working in his chosen field. He might have been a counterpoint to the more technocratic approach taken by Hütter and, thus, moving early German work closer to that of the Danes. It was the Danes and Danish design influence that came to dominate the wind industry and not that of Germany and the design philosophy espoused by Hütter.
As I said, this was one very deep rabbit hole. What other pioneers of wind energy have I missed?
See also Bibliographic Entries for Dimitri Stein German-American Engineer.
Stein, Dimitri. “Bedeutung und Fortschritte der Windkraftausnutzung in Dänemark.” Elektrizitaetswirtschaft 41 (1942): 346–49, 370–74, and 390–92.
Stein, Dimitri. “Verwertung von Windkraft in der Landwirtschaft der UdSSR.” Elektrizitaetswirtschaft 40 (1944): 54–56.
[15] Heymann, Matthias. Die Geschichte der Windenergienutzung.
