Solar harvester automatically switches between heat/ electricity output based on ambient temperature: no sensors, motors, electronics

https://techxplore.com/news/2026-03-harvesting-electricity-sun.html

"Fresnel lens, sealed cavity containing water... above dew point water remains vapor creating high refractive contrast focusing sunlight sharply onto small, high-efficiency PV cell, maximizing electricity production for air conditioning... below dew point water condenses into thin liquid film blunting lens's focusing power, sunlight bypasses PV cell/ enters building with 90% solar-to-heat conversion efficiency... scalable, could be integrated into smart windows/ building facades... future: wide-angle for more hours"