Abstract: A solar energy collector comprising a solar energy absorber, a light transmitting top plate spaced apart from and in a plane parallel to the solar energy absorber, and an array of light transmitting cells intermediate to and in a plane perpendicular to the top plate and solar energy absorber. The collector may also include a light transmitting bottom plate intermediate the solar energy absorber and the array of cells. The bottom surface of the top plate or bottom plate, preferably the latter, is coated with a low emissivity coating. All surfaces of the top and bottom plates may also be coated with an anti-reflective material.

Abstract: The present invention is a thermal insulating material comprising layers of thin walled hollow glass or plastic tubes stacked together so that their longitudinal axes are perpendicular to the direction of heat flow. The tubes are preferably eliptical in cross-section with the larger axes of the elipse also being aligned in a plane perpendicular to the direction of heat flow. The tubes may be sealed at each end or open; if sealed they may contain air or a low conductivity gas at atmospheric pressure or less than atmospheric pressure. In preferred embodiments the internal surface of the tubes are coated with a reflective material.