Semi-transparent solar energy thermal storage device

Claim 1

A visually transmitting solar energy thermal storage device comprising, a visually transmitting exterior panel having interior and exterior surfaces, a visually transmitting solar absorber panel located interiorly of said exterior panel and substantially parallel thereto, sealing means between the exterior panel and absorber panel for forming a liquid-tight containment chamber therebetween, a visually transmitting thermal storage liquid substantially filling said containment chamber, a low vapor pressure liquid layer that floats on and seals the top surface of the thermal storage liquid, a heat mirror substantially covering a surface of said exterior panel for reducing radiative heat transfer through said device, said sealing means comprising peripheral containment walls having a filler hole in an upper portion thereof, and further comprising a porous filter plug in said hole for preventing the introduction of contaminants into the containment chamber, said thermal storage liquid including an algicide, and said thermal storage liquid including a chelating compound for keeping metal ions in solution.