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This Biophysicist 'Sun Queen' Harnessed Solar Power

Hungarian-American biophysicist and inventor Mária Telkes illuminated the field of solar energy. She invented a solar oven, a solar desalination kit and, in the late 1940s, designed one of the first solar-heated houses

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Paula Mangin

Today we tell the story of Mária Telkes, one of the developers of solar-thermal storage systems. Telkes was so dedicated to the world of solar energy that while she was working at the Massachusetts Institute of Technology, she earned the nickname the “Sun Queen.” Over her lifetime, she registered more than 20 patents, nearly all related to harnessing the power of the sun.

Her inventions that utilized solar energy included an oven, a desalination device and one of the first solar-heated houses, the Dover Sun House, constructed in 1948. We heard about Mária Telkes from Erin Twamley, a children’s book author who shares the stories, careers and the superpowers of everyday women. She said she would love to see Telkes in every fifth grade classroom to inspire young people.


[New to this season of Lost Women of Science? Listen to the most recent episodes on Flemmie Kittrell and Rebecca Lee Crumpler and Eunice Newton Foote.]

Lost Women of Science is produced for the ear. Where possible, we recommend listening to the audio for the most accurate representation of what was said.


Johanna Mayer: In 1948, a strange house appeared in Dover, Massachusetts. 

Today, Dover is a well-to-do suburb of Boston, but it used to be rural farm country. Narrow roads, yawning green lawns, fields with horses. The houses tended to be stately Colonials, or maybe the newer ranch style. 

So when this new house went up… it stuck out. Big time.  

Some say the house resembled a wedge of cheese. Imagine buying a triangular wedge of cheddar and placing it on the table with the wide side facing down. That’s the shape of this house. The slanted part of the cheese wedge – the back of the house – looked fairly normal, with brown siding and some windows. But the other side of the wedge - where the rind would be - was a futuristic space house. It was lined edge to edge with eighteen 10-foot-tall, imposing glass windows… designed to beckon in the sun.

I’m Johanna Mayer, and this is From Our Inbox, a series from Lost Women of Science. This unusual home was called the Dover Sun House. And it was the brainchild of Hungarian-American biophysicist Mária Telkes.

Erin Twamley:  My name is Erin Twamley. I am a children's book author who loves to share the stories, careers, and superpowers of everyday women. 

Johanna Mayer: Erin writes books about what she calls “everyday superheroes” – women who work in STEM, or science, technology, engineering, and math. It was Erin who first wrote to us about Mária Telkes. 

Erin Twamley: I would love Dr. Maria to be in every fifth grade classroom. Dr. Maria really helped to shape some of our understanding of what we can do with solar power.

Johanna Mayer: Mária Telkes was born in Hungary in 1900, and got interested in solar energy while studying at the University of Budapest. By 1924, she’d gotten her PhD in physical chemistry, and she decided to move to the US to work as a biophysicist at the renowned Cleveland Clinic. Biophysicists generally apply the principles of physics and math to biological systems – for example, when she was at the Cleveland Clinic, Mária worked on a photoelectric machine that recorded brain waves.  

After a few years, she moved to MIT. And she became so dedicated to the world of solar, that she soon earned a nickname: the Sun Queen.

Over her lifetime, the Sun Queen would earn more than 20 patents, nearly all of which had to do with harnessing the power of that great big burning ball in the sky.

Erin Twamley:  I think one of the neatest things that she came up with is called one of the first solar ovens that would be easy to use, and that could be used in remote places.

Michelle Addington: This one is near and dear to my heart because I built a portable, lightweight solar oven when I was a mechanical engineering student.

Johanna Mayer: This is Michelle Addington – she’s the former Dean of the University of Texas at Austin School of Architecture.

Michelle Addington: We cannot comprehend the stunning amount of thermal energy that is contained in the sun. We don't come close to comprehending it.

Johanna Mayer: Mária used this observation to build an ingeniously simple solar oven. Basically, it was that insulated room with a window, shrunk down to oven size. Metal plates and mirrors inside the box captured the solar wavelengths that came through the glass window – and the oven would heat up to 350 degrees. During a demonstration of the oven, Mária said, “Everything seems to taste so much better when it is cooked by the sun.” 

When World War II broke out, Mária was temporarily reassigned to the U.S. Office of Scientific Research and Development. And she was tasked with solving a serious problem: American soldiers, stranded in the Pacific theater, were dying of dehydration. Once again, Mária turned to the sun.

Michelle Addington: You take your saltwater. You sort of spread it on a surface ideally a black surface where it's going to receive direct sun. The water will evaporate. Obviously the salt will be left behind. So the water evaporates and it'll collect on a surface that's above it. Due to surface tension or friction, as the water vapor collects on that surface, it will start to condense. 

Johanna Mayer: And voila – drinkable water. The military would eventually include her solar desalination device in its official standard-issue emergency medical kits.

And in 1948, Dr. Mária Telkes turned her focus to what would perhaps be her most ambitious project yet: the Dover Sun House.That strange, cheese-shaped house with a row of 18 windows, designed to use solar energy to heat a home. 

The house was funded by the philanthropist Amelia Peabody and with the help of the prominent architect Eleanor Raymond, Mária designed a house fit for a Sun Queen.

Here’s how it worked. Those windows? They were sun collectors. There were two layers of glass, separated by some airspace and backed by a black sheet of metal. As the sun shined, the air in that space would warm up. And Mária put giant vats of Glauber salts near that warm air. 

Michelle Addington: And so what would happen is these sort of salts began to liquefy. They were absorbing and absorbing and absorbing and absorbing and absorbing heat. They basically functioned as a battery. You know, so if there was no place for them to dump the heat, you know, they would just keep going more and more liquid. 

Johanna Mayer: So how do you extract the warm air from those salts? 

Michelle Addington: Simply just sort of pass air over that. If you passed air over that, you started to cool down these large containers of salts. You'd heat up the air as you were cooling down the vats of salts, as they were giving up their heat.

Johanna Mayer: Fans circulated that warm air throughout the house.

Michelle Addington: This allowed for stable conditions; it acted as a fantastic battery, uh, and it could function for a number of days without having sun on it because of the amount of energy that was contained within this sort of large collection of vats. 

Johanna Mayer: For two years, the house functioned pretty much as planned. A family moved in, and took up residence in the cheese-shaped Sun House, giving tours to reporters and curious rubberneckers alike. It was the only home in the world heated entirely by solar power. But during the third New England winter, cold hard reality set in. 

Michelle Addington: Two problems: The salts themselves are extremely alkaline and therefore given to corrosion. And corrosion is actually what sunk the project. 

Johanna Mayer: Ultimately, because of the endless melting and cooling and recrystallizing of the Glauber salts, the substance wasn’t being mixed properly. 

And the other problem? Well, it’s one that maybe wasn’t top of mind for Mária back in the ‘40s, but is essential for us to think about today.

Michelle Addington: The biggest problem is the fact that cooling is one of our our biggest needs. So much of the focus, of the entire passive solar movement, a lot of natural systems for buildings was built on the assumption that we needed heat. That's not the world that we're in. It's easy to heat. It's really hard, takes much more energy to cool, three times more energy to move a BTU of heat out of a building than it is to put a BTU of heat into a building. 

Johanna Mayer: By 1954, the Sun House’s solar heating system officially went dark. But Mária Telkes wasn’t discouraged. The Sun Queen knew that no single house could answer the world’s solar power issues.            

She once said: “The problem of the sun-heated house cannot be solved by one or two experimental houses. But each new house is another experimental stepping stone toward the use of the sun as a fuel resource.”

Dr. Mária Telkes died in 1995, at age 94. But her legacy lives on. Today, the number of people installing solar panels in their homes is consistently rising – and in a recent Pew study, 39% of homeowners surveyed said they were seriously considering going solar.

And to those people still considering… I’ll leave you with the Sun Queen’s own words, from 1951: She wrote:  “Sunlight will be used as a source of energy sooner or later anyway. Why wait?”

Katie Hafner: Thanks to Erin Twamley for writing to us about Dr. Mária Telkes. If you want to learn more about her children’s book series on women who work in STEM, check out her website. There’s a link in our episode description.

This episode of Lost Women of Science: From Our Inbox was produced by Johanna Mayer and engineered by Aaron Peterson. The senior producer was Erica Huang. Our executive producers are Amy Scharf, and myself, Katie Hafner. Lizzy Younan composes our music. We get our funding from the Alfred P. Sloan Foundation and Schmidt Futures. And Paula Mangin did our wonderful From Our Inbox art. PRX distributes us and our publishing partner is Scientific American. 

Here at Lost Women of Science, it is our goal to rescue female scientists from the jaws of obscurity, but we need your help! If you know of a female scientist who's been lost to history, let us know! You can go to our website to send us an email at lost women of science dot org. You'll also find the phone number to our tip line. We love getting calls to the tip line. I’m Katie Hafner. Thanks for listening.

Thanks for listening.

Further reading:

Libguides: MIT Buildings: Dover Sun House.” Dover Sun House - MIT Buildings - LibGuides at MIT Libraries,

Nemethy, Andrew. “In 1948, We Were Human Guinea Pigs in the Strangest House in Dover - The Boston Globe.” BostonGlobe.Com, The Boston Globe, 20 Mar. 2019.

“The Marvelously Inventive Life of Mária Telkes.” PBS, Public Broadcasting Service, March 17,2023 

Johanna Mayer is a writer, host and producer.
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Katie Hafner is host and co-executive producer of Lost Women of Science. She was a longtime reporter for the New York Times,, where she remains a frequent contributor. Hafner is uniquely positioned to tell these stories. Not only does she bring a skilled hand to complex narratives, but she has been writing about women in STEM for more than 30 years. She is also host and executive producer of Our Mothers Ourselves, an interview podcast, and the author of six nonfiction books. Her first novel, The Boys, was published by Spiegel & Grau in July. Follow Hafner on Twitter @katiehafner
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The Lost Women of Science Initiative is a 501(c)(3) nonprofit with two overarching and interrelated missions: to tell the story of female scientists who made groundbreaking achievements in their fields--yet remain largely unknown to the general public--and to inspire girls and young women to embark on careers in STEM (science, technology, engineering and math).
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