U.S. Patent 2,808,494 for a “Method and Apparatus for Storing and Releasing Heat” is granted to Maria Telkes.
On 1 October 1957, U.S. Patent No. 2,808,494, titled “Method and Apparatus for Storing and Releasing Heat”, was granted to Mária Telkes. Building on her earlier work, this patent refined the processes by which heat could be stored in specially designed units and then released in a controlled manner.
The invention described improved configurations and operational methods for phase‑change heat‑storage systems, enhancing efficiency and reliability. It reflected Telkes’s continued experimentation with materials and system design to solve practical problems in solar heating. By the late 1950s, she was among the world’s leading experts on thermal storage for solar applications.
This patent is significant because it illustrates the evolution of solar‑thermal technology from initial prototypes toward more mature, deployable systems. Telkes’s series of patents formed a coherent body of intellectual property that influenced later designers of solar‑heated buildings and contributed to the knowledge base of modern renewable‑energy engineering. As a woman inventor with multiple patents in an era when women were often excluded from engineering leadership, Telkes’s 1957 grant affirmed her long‑term role in shaping the technical trajectory of solar energy and underscored the depth of her expertise in managing the intermittent nature of renewable heat sources.