The Life of the Solar Pioneer Karl Wolfgang Böer

By Karl W. Böer

In 1973, Dr. Ber created the Solar One house, the first house to convert sunlight into electricity and heat. His leadership made a lasting impact on science, engineering, and the solar industry. The Life of the Solar Pioneer Karl Wolfgang Ber describes the life of one of the most influential and recognized solar energy pioneers. It is a must read for anyone interested in the modern development of solar energy, Bers dynamic life as one of the key movers in the field, and his world authority in CdS (Cadmium sulfide).

It provides rare insight into the personal life of a scientist growing up in turbulent postwar Berlin. After his emigration to the USA and his transformation as a leader in solar energy, he set the direction for the future in significant ways:

Bridged the divide between academia and industry
Wrote over 350 science publications, dozens of books, and patents
Created the most successful international solid state physics journal
Promoted worldwide implementation of solar energy

• Language: English
• Publisher: iUniverse
• Release date: Jul 13, 2010
• ISBN: 9781450228794

Karl W. Böer

KARL WOLFGANG BÖER, born in Berlin, Germany, a Distinguished Professor at thirty-five, immigrated to the United States in 1961. World authority in CdS, pioneer in solar energy, he created the Solar One house at the University of Delaware in1973 thereby initiating the modern movement of solar in the early 1970s. A collection of dramatic poems by the author, written in 1945/6 is published by iUniverse under the title War and Peace, by the Young Wolfgang Böer in original German with English translation.

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Contents

Preface CdS to Initiate Global Solar, the Golden Thread

Introduction: The Rise of a Prominent Scientist

Chapter 1    Growing Up in Berlin

Roots

Lessons Learned at Home

Family Time

Still More Lessons Learned

The Young Scientist

Radios also Capture Young Wolfgang’s Interest

High School Years

Chapter 2    The War

Preparing for the War

Daily Life during Wartime

Weltanschauung

Learning to Be a Pilot

Waiting

The Young Soldier

Letters from Home

A Difficult Decision

A Long Journey

Chapter 3    Recovering

Picking Up the Pieces

Improvising in Berlin

Living with His Uncle

Return to the University

Starting a Family

Flying through School

Professor Robert Rompe

Better Times

His Son

Return to his House

Chapter 4    Doctoral Student

A Foray into Film Animation

No Dumb Questions

A Crystal in a Drawer

New Challenges

Physics and Politics

The New Laboratories

Dielectric Breakdown.

Seven CdS Breakthroughs

The Group that Plays Together

No Challenge Too Great

Too Much Work Takes Its Toll

Traveling as a Way to Relax

Chapter 5    Professor Böer

Creativity in the Classroom

The Great Discovery

Another Important Discovery

Divorce and Marriage

The Road to Promotion

Creation of the Fourth Physics Department

The New Journal

The Berlin Wall

Leaving Berlin

Visiting Berlin as an American Citizen

Chapter 6    Anderes Land, Andere Sitten

Shoes, Rent, and Rooms without Walls

The Language Barrier

Freedom?

The Streets of New York

A Different Side of America

Friends and Neighbors

Moving to Delaware

University Life

CdS Research at the University of Delaware

One more Seminal Paper on High-Field Domains

Applied Research

Returning to the Wings

More Adjustments

Chapter 7    Solar Böer

Renate

Broader Horizons

A New Partnership

Stan Ovshinsky

Solar Energy

The Institute of Energy Conversion (IEC)

Delaware Conference to Evaluate the Potential of Solar Energy

Katie

The Foster Children

Dirk

Dora

The Böer Farm

Katie the Entrepreneur

Reinhard

All in the Timing

Solar One

The Böer Residence

The Solar Museum

Solar Energy Systems, Inc.

Changing Times

A Difficult Truth

One Last Try

The Dissolution of a Dream

Chapter 8    New Horizons

The American Solar Energy Society

Physica satus solidi Anniversary

Böer as an Author

German Reunification, Berlin, 1989

Looking for the Past

Researching with Former Colleagues

Advising WISTA

Working with Renate

Celebrations

Chapter 9    The Man within the Scientist

Travel Together

Sports and Hobbies

Flying

Builder

Sports and Games

Chapter 10 Conclusions

University Professorships

Honors, Awards, International Acclaim

Awards

The Karl W. Böer Solar Energy Medal

The Awardees

Karl W. and Renate Böer Professorship

Afterword    The Future of Solar Energy

Goals for the Future

Solar Cells

Environmental Factors

Other Effects of Pollution

Initiatives to Mitigate

Changes to Humanity

Appendix    Selection of Böer’s Work

Selected Publications in Chronological Order

Preface

CdS to Initiate Global Solar, the Golden Thread

About ten years ago, I was named a solar pioneer by a distinguished panel at an international congress. When I heard the laudation, detailing how I had brought solar energy into focus with the Solar One house that we built at the University of Delaware, I much appreciated the honor; however, the main purpose to build the house, was the CdS1-based solar cell on its roof that made the concept of such a house promising for the future. A thin layer of this material was able to convert solar energy into useful energy for the house. It was the first time in the world this material had been used as part of the roof; it converted sunlight with the same solar cell panel into heat and electricity. It was built into the roof, not on top of it. And we stored the heat and electricity for the time later in the day when we needed it. Today, I know that we were about three decades ahead of the time, because it is just recently that such panels have been commercially produced and built into roofs instead of on top of their plywood and shingles.

Already then, Solar One was the platform for us to make CdS known worldwide. I hoped that this model house would be covered by the press on every continent, because it was so unusual, so advanced. I could only hope that one day CdS would be one important ingredient in the solar panels on most of the roofs that would harvest solar energy and provide us with the highest form of energy: electricity.

Today, the use of CdS on top of another layer of cadmium telluride, has become a multibillion-dollar industry. Here CdS is used to improve thin-film solar cell efficiencies from 8 percent to 16 percent2. I know now that my expectations could indeed become reality in the future.

How did I get there? A few decades earlier, as a young student, I stumbled by accident upon a number of small crystals in one of the drawers at the physics institute. These crystals turned out to be cadmium sulfide (CdS) platelets.

Through my investigation of the electrical and optical properties of these crystals, I earned my diploma and my PhD at Humboldt University in Berlin. With many of my students, first in Berlin and later, after my emigration to the United States, at the University of Delaware, I authored over two hundred publications reporting the results of our research on this material. Later, as the director of the Institute of Energy Conversion and the CEO of SES, Inc., I led a large research and development group to further improve the CdS-based solar cells.

After an intermission of almost three decades in which I became active in developing the American Solar Energy Society and wrote many books on solar energy and solid-state physics, and followed many invitations to present our results worldwide, I recently decided to focus again on the subject of my life: CdS. With many new research results at hand, I was able to contribute to solving the puzzle of why CdS improves the solar energy conversion of thin-film solar cells so dramatically. I published these results just recently (Böer 2010a), as a fitting culmination of my life’s work on the global impact of this material.

Dr. Ester Riehl, an adjunct professor at the Institute of Foreign Languages at the University of Delaware, was recommended to me by its director, to give me a hand in developing my life’s story. I am grateful to her for undertaking the challenge to research my archives and interview me extensively, thereby becoming so familiar with my life that she could write about it.

I would like to especially thank my wife, Renate, who, for over four decades, has helped me in so many facets of my life, endured extended periods in which I seemed to be more married to science than to my family, and always encouraged me, enabling me to move through the ups and downs of life, always with a smile and holding my hand.

Karl Wolfgang Böer

Introduction: The Rise of a Prominent Scientist

Karl Wolfgang Böer, PhD, distinguished professor emeritus of physics and solar energy, holder of thirty patents, author of over three hundred and fifty scientific articles, founder and first director of the University of Delaware’s Institute of Energy Conversion, former chairman of the board and chief scientist of Solar Energy Systems, and two-term president of the American Solar Energy Society, recipient of many top awards from various professional societies, and now a fellow of four societies, has achieved it all. Highly respected by his peers and named a solar pioneer, he was recently inducted into the world’s Solar Hall of Fame. He has earned the right to rest and look back at a successful life.

Young Wolfgang was not a very good student in school. His grades were spotty. Even in high school, he liked the sciences, though he neglected many of his other subjects. His own point of view on this subject is best represented by the following exchange he reported having with his father.

When he brought home his yearly report card at age fifteen, he gave it to his father, who was sitting in the leather chair in his study, puffing on a big cigar. Father Böer was not happy with what he saw and said, Wolfgang, you have been excellent in physics and the other sciences, but you have neglected the humanities. How do you respond?

The young boy answered, True, it is the sciences that fascinate me, and I see a definite future in them. I think I could excel to the top and achieve significant results that will help all of us. I agree with you that a good basic knowledge of humanities is essential to be a respected person in society, but when I focus on one goal, I may have to postpone other parts of my education to the future and catch up at a later time.

His father was not satisfied and continued, What specifically do you have in mind? Do you want to be a medical doctor, or what?

No, not a doctor, Wolfgang replied. I cannot stand the sight of blood, but there is another reason why I feel strongly that I should not become a doctor. I see much higher rewards in becoming a scientist. Here, I can help to improve conditions in the society which may be beneficial to more than one or a few.

Wolfgang’s father recognized his determination and let him go his way.

Later, in the military, Wolfgang fulfilled his promise and read up on many subjects that he had neglected earlier.

After the war, he returned home to Berlin. His harmonic life had been interrupted by the tragic deaths of almost his entire family; losing with them the guiding hands of his parents. Yet his determination to succeed became even stronger. After his university, which was closed at the end of the war, opened again, he studied intensively, and the rewards he obtained from his success replaced the comfort and the advice he had been used to receiving from his parents. He excelled at every single step in his academic career and was soon recognized beyond the borders of his own country.

His smooth path to the top was suddenly interrupted by a devastating political event: the building of the Berlin Wall. He was forced to chose resigning from a prominent position at the Humboldt University and to start anew in the United States of America.

Continuing his research and teaching in the United States, he soon recognized that he needed to take one step further and turn from solid-state physics, his academic field up to this point, to solar energy. In this field, he turned out to be an inventor, an entrepreneur, and a leader. With creative ideas, dedication to his work, and strategic goal-setting, he started to move to the forefront and by his own example induced so many others to follow in his footsteps, which to him was even more of a reward.

He made a career of understanding solid-state physics which helped him to further develop solar cells, and the knowledge of the solar energy field, and his concerns about the planet, turned him into a passionate advocate of alternative energies. He still publishes and writes about the need to expand solar and other alternative energy sources. He has seen that the technology works, having directed the design and construction of the first solar demonstration house in 1973. Through that project, he learned what worked well and what did not and went on to solarize his own house in 1976. At the time he was developing these projects, the technology still needed a great deal of further improvement and the cost of converting to solar energy was too high for most people. More than thirty years later, the technology has improved, the economic cost has substantially decreased, and most important, the environmental urgency has dramatically increased. Böer insists that decreasing dependence on fossil fuels through expanded use of wind and solar energy would only require effort and incentives from governments and reassigned priorities in businesses. He now uses his contacts in the spheres of academia, business, and governments around the world to bring about change in how people produce energy. His life’s experiences have prepared him for this task, and he sees it as an obligation rather than an opportunity. He will not ignore his perceived call.

But with others recognizing the potential of his earlier work, he was invited by a prominent publishing house to summarize and compose a text book that would be of help to future student generations. He wrote a five-hundred page volume about the basic science that is necessary to understand solar cells. All of this was completed in less than a year, which would be enough work for most fifty-year-olds. But when Professor Böer wrote the summary of his earlier work, he suddenly recognized that bringing it all together could solve a decades-old puzzle. It was CdS then that was the center of his research and permitted his first pioneering effort into solar energy, and it is CdS now, that, as a thin layer on top of many thin-film solar cells, improves their conversion efficiency substantially. It did not take him long to put it all together, and he has now published three groundbreaking papers.

Now, he is satisfied that his six-decade-long work in CdS will bring the fruit he has always hoped for. After reviewing what I found in the archives about his life, having already forgotten many details, he relaxed at his winter home in Florida, in his orchid garden surrounding his pool, to reminisce and to open up to hours of undisturbed interviews with me.

Ester Riehl

Chapter 1    

Growing Up in Berlin

Wolfgang, as he was called by his family, lived a sheltered life as the only child in his close-knit family. Most of his relatives lived within one block, and his parental grandparents were only a two-hour train ride away. They visited each other frequently.

Roots

Wolfgang’s mother, Charlotte Lotte Gruhlke, grew up in Posen with two older sisters and a younger brother. She lost her father through an accident when she was eleven years old, but her mother, Clara (Ciecinsky) Gruhlke, managed to educate the children well on a small pension. At the end of World War I, Posen became Posnan and part of Poland.

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Clara Gruhlke (Omi)

The Gruhlkes preferred to continue living in Germany and moved to Berlin. Here, the daughters contributed to the family’s budget, and they were able to live in a nice apartment in Charlottenburg, near the Tiergarten, a large park in the center of Berlin.

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Ella, Lotte at the Piano, Frieda and Omi, sitting

Lotte worked first as a junior secretary but quickly acquired the technical skills to become a personal assistant to Mr. Ohnesorge (12 years later the German postal minister). In 1925, she helped him to install the first radio link for an opera transmission from Königs-Wusterhausen to Berlin.

Wolfgang’s father, Karl (Wilhelm Ernst) Böer, grew up in the small garrison town of Ludwigslust (Mecklenburg) as the only child of Karl Böer, a military saddle-maker for the cavalry, and his wife, Marianne. Wolfgang together with his parents visited his grand parents often.

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Opa, Oma, Mutti and Wolfgang 5years old in Ludwigslust

Karl was determined to attend the Gymnasium, the college-preparatory high school about a hundred kilometers away in the town of Rostock, and later, to go even farther away, to Hannover to study at the university. He knew what he wanted. It was quite unusual for the son of a small-town military family to attend college. When he graduated in 1922 with a diploma degree in electrical engineering, he found a job at the Siemens Halske Company in Berlin, where he eventually became the chief engineer in the field of high-frequency furnaces that smelted metal by means of induction. Siemens sold these furnaces across Europe. Böer’s responsibilities were to deliver them to the clients and inspect the installation.

By 1932, he was considered important enough to warrant an assassination attempt by the Soviets while he was working for Siemens in Leningrad.

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Karl Böer (center) shown here on a mission of Siemens in Leningrad

Though it looked like an accident—a heavy steel beam fell and landed only inches from him—he and his colleagues at Siemens took it seriously and he no longer traveled to the Soviet Union, especially since a few weeks earlier, two British engineers had been killed. The Soviets apparently had learned enough from their European colleagues and planned to nationalize their European subsidiaries. The Siemens group in Leningrad would become Electrosila and would later produce the machines that separated uranium and lithium for their atomic bombs.

As a young engineer, he liked to walk in the Tiergarten. One Sunday morning, he witnessed two dogs fighting with each other. One was Lotte’s German shepherd, Prinz, who had been attacked by a Doberman. Karl came to the Prinz’s rescue and thereby met Lotte.

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Charlotte and Karl Böer at their wedding day, September 3, 1925.

After a short courtship, they were married on September 3, 1925. After the wedding, Charlotte stopped working (the usual custom for a German family at that time) and prepared herself to become a mother. Wolfgang was born on March 23, 1926, in Charlottenburg, a few weeks early. A complication with his birth prevented further pregnancies. This became a bit of a problem for Wolfgang. His attempts to rectify the situation by means of a sugar plate on the windowsill did not bring success; the stork did not find the sugar and did not deliver a baby, so he remained the only child.

Lessons Learned at Home

After the family’s move from Charlottenburg to Spandau, their home was about a mile from the elementary school. Wolfgang soon walked to school by himself; he was never late, but it took him a long time to adjust. He was fidgety, and his mind always wandered to other things—though, when asked, he usually knew what the teacher was talking about. His grades stayed low, ranging from satisfactory to fair. One day, his mother went to see his teacher. From then on, she supervised his homework, sometimes guiding his hand to improve his handwriting. All his grades rapidly improved to good or better. His mother’s concern and assistance had left a lasting effect on the young schoolboy.

Wolfgang also learned to be organized from his mother. As he collected toys and books over the years, they began to clutter his room. His mother bought a bookcase for him. After stacking his books and toys on the shelves, he called his mother to show off his work. Seeing that he had just piled them up on the shelves in no particular order, she simply told him, No, that won’t do. Then she showed him how to organize it, packing similar items into small boxes and placing them in neat rectangular order. He began keeping his desk neat as well: pencils, books, and papers lay in straight rows, and everything on the shelf behind the curtain was always neat.

He learned that it was easier to find what he needed if everything was well organized. This habit stayed with him; he always kept his work space neat. Even his color pencils were ordered in rainbow sequence—and they still are.

Though his family put great emphasis on his intellectual development, they did not ignore the importance of physical health. When he was small, his mother would send him outside with his scooter to get fresh air and play with other children. From his father, Wolfgang learned the precept of mens sana in corpore sano: a healthy mind exists only in a healthy body. Despite an injured knee, the senior Böer used to walk regularly with Wolfgang through the nearby forest and insisted on other regular exercise.

Wolfgang frequently visited his grandmother, the matriarch of the family, who lived only a block away, and was often challenged to help with little things. One day, he found an old alarm clock that no longer worked. He asked her whether he could repair it. She didn’t believe he could but didn’t object. So he took it apart, put all the parts on white paper, cleaned and oiled them, and put the clock back together; it worked again. Omi was impressed. He was six years old. When he tried this later with his aunt and dared to take the spring out of its housing, it snapped. That was the last time he was permitted to take a clock apart.

The family also visited Wolfgang’s paternal grandparents in Ludwigslust every summer, and Wolfgang and his father went for long walks there. These walks among the quiet trees provided not only physical exercise but lessons on nature for young Wolfgang that he still vividly remembers. He admired the trees in their orderly, straight rows and that it would take a half of a human lifetime before they could be cut for lumber. His father pointed out the different varieties of trees and ferns, and Wolfgang learned to recognize many kinds of wild mushrooms and carefully picked some of the eatable ones.

Family Time

In Spandau, they kept a small sixteen-foot sailboat and sailed almost every weekend on the Wannsee in the summer. Here, young Wolfgang could play in open air. Wolfgang’s father was an avid swimmer. One day, when Wolfgang fell from the deck and his father had to jump in to fish him out, he decided it was time for swimming lessons. He had to pass two official swimming tests before he would be allowed to swim in the lake. He proved his stamina by swimming with his father to the opposite bank of the small lake and back.

When they later bought a twenty-four-foot cruiser with a cabin big enough for the three of them to sleep in, they took much longer trips. Wolfgang learned about sailing. His first responsibility was to man the foresail and also to have the sheet rolled together neatly like a snail on deck.

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Weekends on the boat: young Wolfgang and cousin Dieter with his parents, aunts Ella and Frieda, and Omi

They took one long trip from Spandau to Lübeck Bay. There, Wolfgang watched his mother embroidering and decided he wanted to do some of it too. He first embroidered a small tablecloth and then finally finished one for his grandmother for Christmas.

At home, the family relaxed together by making music. Mother or Father played the piano, sometimes choosing folk songs that they could sing together, sometimes the classical music of Mozart, Haydn, or Bach. When he was six, his mother wanted him to learn to play the piano. Like so many children, the idea sounded good to him, but he did not realize how much practice would be necessary. He started about a month before Christmas 1932. Wolfgang thought he could surprise his father by playing some Christmas carols when he returned home, and he did.

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Wolfgang and his family celebrated Christmas in 1932

after his father returned from Russia

with framed oil panting as the Chritmas gift.

He would come to regret that he didn’t devote more time to practicing when he later wanted to play the piano but did not have the capability to play as well as he wanted.

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Wolfgang still playing occasionally piano

The family was saving money to build a house, so Wolfgang received only a few Christmas gifts. They included a carefully selected book or some kits. There were also some building sets, deliberately chosen to teach him how to finish each project with the parts he received.

Still More Lessons Learned

His mother, however, did take pity on him when he faced a more substantial failure. When he was ten years old, he found an old crystal radio from his mother’s time working with Mr. Ohnesorge. It was tucked away in a corner of the attic. He took it apart to rebuild it, just as he had done earlier with the alarm clock. Using the battery and bulb from his flashlight, he sent an electric current through the parts of the radio, and he was happy to see that the inductor and some other parts allowed the current to go through and lit the lightbulb. But when it came to the capacitor, he had no such luck. Wolfgang assumed that it was defective. He fiddled until he had created a short circuit, allowing the current to pass through, and then put the parts back together. Now the radio was truly broken. This exercise with the radio was Wolfgang’s first foray into electrical engineering. His mother observed his efforts, which were tenacious but without success. After a discussion with his father, she bought Wolfgang a new crystal radio, even though this purchase went against the family’s philosophy of enjoying only music that they played themselves. Wolfgang had to promise to listen to the radio only occasionally in his bedroom.

He also collected butterflies and mounted them, grew plants, and fed little animals in his terrarium, as many other boys his age did. His collections included a large number of stones and minerals and a variety of metals and alloys. He put them all in drawers with dividers to order and label them.

After they moved into the new house, Wolfgang was able to set up his own workshop in the basement. He equipped it with tools he had received from his grandfather. This became the foundation of his more elaborate shop.

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A typical gathering of the extended family, circa 1937: Standing in back, Frieda Gruhlke, Charlotte Böer, Ella Hartwig, Else Grulke; seated, Wilhelm Gruhlke, Klara Gruhlke, Willi Hartwig, Karl Böer, Marianne Böer; on the floor, Wolfgang Böer and Dieter Hartwig.

The Young Scientist

Young Wolfgang also set up his first little chemistry laboratory, based on a kit he received for Christmas in 1937. He put it in a separate room of the basement. With his father’s help, the small lab grew to include a larger variety of chemicals, some test tubes and beakers, an Erlenmeyer flask, and a spirit burner. Over the years, his stock grew, and by 1941, he had more than two hundred different chemicals, along with distillation systems, petri dishes, and all types of tools and devices with which to test and perform even complicated organic chemical reactions.

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The young scientist engages in smelly chemistry experiments on the veranda.

With growing interest, Wolfgang performed chemical experiments that were more fun than the biological or physical experiments, because they generally gave results more quickly. They were sometimes also quite exciting. At first, he followed the instruction manual that came with his chemistry set, but then he looked up experiments from other books, such as Die Chemie im Haushalt (Chemistry in the Household).

He quickly learned the properties and uses of many chemical compounds. One such was the powerful oxidation agent sodium perchlorate. He came up with a practical application for it. His mother had a porcelain bowl that had food burned on it. When he melted a bit of sodium perchlorate in the bowl and cautiously swished it over the burned area, small flames appeared, and with a little poof at the soiled spot, it was clean again. His mother soon saw how useful it was to have a chemist in the house, and Wolfgang became her right hand when she had to remove stains from kitchen utensils and from clothing. Since different stains required different chemicals to remove them, he had to check the necessary chemicals carefully. Years later, when he was a soldier away from home, his mother