places · updated 2026-08-11
Dover Sun House
confidence: high volatility: cold verified: 2026-08-11fresh
The 1948 Dover, Massachusetts solar house by Maria Telkes and Eleanor Raymond, funded by Amelia Peabody. Used 21 tons of Glauber's salt for phase-change heat storage. Achieved 91% solar heating its first winter but failed by the third. Demolished 2010.
Built 1948 on Amelia Peabody‘s estate in Dover, Massachusetts (42°13’36”N, 71°15’30”W). Designed by architect Eleanor Raymond with MIT solar researcher Maria Telkes. ~1,620 sq ft, wedge-shaped and south-oriented.
Solar heating system
56 double-glazed modular panes over black metal sheet formed the south-facing heat collector. Fans blew sun-warmed air into three ground-floor “heat bins” containing metal drums filled with 28 tonnes of Glauber’s salt (sodium sulfate decahydrate). The salt underwent phase change at 32°C — melting while absorbing heat during the day, recrystallizing at night to release stored heat. No backup heating system was installed.
Achieved 91% of space heating demand in the 1948–49 winter. Life magazine (1949): “A New House in Dover, Mass., Has Been Comfortably Warm All Winter Without a Furnace.” Popular Science called it “more important, scientifically, than the atomic bomb.”
Failure and demolition
By the third winter, sodium sulfate stratified into layers, losing its phase-change capacity. Containers corroded and leaked. Electric heaters and eventually an oil furnace were added. The solar system was removed entirely in 1954. The house was demolished in 2010 and replaced with a new structure featuring a modern solar array.
Full article: Dover Sun House
See also
- Maria Telkes
- Eleanor Raymond
- Amelia Peabody
- Hoyt Hottel
- Dover Sun House (concept article)