U.S. Patent 2,677,243 for a “Method and Apparatus for the Storage of Heat” is granted to Maria Telkes.
On 4 May 1954, Mária Telkes received U.S. Patent No. 2,677,243 for “Method and Apparatus for the Storage of Heat”. Complementing her patents on heat‑storage units and materials, this invention specified how to integrate those elements into a functioning system that could capture, store, and later release thermal energy.
The patent detailed an arrangement of containers, heat‑exchange surfaces, and phase‑change materials designed to work with solar collectors or other heat sources. By addressing both method and apparatus, Telkes provided a blueprint for operational solar‑thermal storage systems suitable for residential or experimental buildings.
Historically, this patent marks a critical step toward making solar heating more than a laboratory curiosity. It offered a concrete engineering solution to match the conceptual promise of renewable energy. The combination of multiple related patents granted to Telkes on the same day underscores her systematic approach: she tackled device design, material composition, and system integration together. As one of the few women directing such comprehensive technological development in the 1950s, she helped prove that sophisticated energy systems could be conceived and patented by women scientists, challenging both gender expectations and skepticism about solar power’s practicality.