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Delia J. Smith

Over 70 Years Ago, Dr. Maria Telkes Built America’s First Solar House

In the late 1930s, Hungarian-born scientist Dr. Maria Telkes took a position as a researcher and professor in the Massachusetts Institute of Technology’s Solar Energy Conversion Project. Already a famous scientist for having invented a photoelectric device that could record brain waves Dr. Telkes was determined to create a home that could be heated without fossil fuels. 

Though her efforts were temporarily delayed by World War II (during which, she invented a portable water desalination kit for stranded pilots and sailors), she returned to her solar research.

Something new under the sun: a home without a furnace

In 1948, she had the good fortune to team up with two other talented and powerful women: sculptress and heiress Amelia Peabody and the talented architect Eleanor Raymond. Peabody’s resources supported the effort, (the technology cost about $3,000 at the time, roughly $32,000 in today’s money), and Raymond designed the residence, located just outside Boston in Dover, Massachusetts. The home was shaped like a wedge - somewhat like a normal home if one chopped it in half – in order to maximize the amount of sunlight harvested. 

The second story south-facing wall (a story higher than the north-facing side) included 18 windows. Sunlight streaming in was then captured by a collector consisting of double layers of plate glass backed by an 800 square foot black metal heat-absorbing sheet. The resulting warm air was then circulated by means of fans to a storage area holding metal drums containing 21 tons of sodium sulfate decahydrate (known as Glauber salts). This phase-change material would melt, storing heat at a constant temperature (just as melting ice consistently keeps the surround water at 32 degrees F). When the temperature of the home dropped at night or during cloudy days, the salts would recrystallize and release heat, which would be circulated by the fans throughout the home. The system was sized to retain sufficient heat to ride through ten consecutive cloudy or stormy days.

The solar home functioned effectively for over two years before the salts permanently separated and lost their effectiveness. Though the project ended, partly resulting from tension between MIT and Dr. Telkes, she continued to invent other solar technologies in the ensuing years. These included a solar cookstove deployed widely throughout India, as well as materials utilized in the U.S. space program. She eventually owned 20 patents, including one filed at the age of 90 for a solar air conditioner, five years before her death in 1995 at the age of 95.