Abstract: A tool is provided for manufacturing parabolic solar reflectors. The tool employs an improved smooth convex parabolic surface terminating in edges remote from the parabolic vertex which are preferably placed under elastic tension tending to draw the edges toward each other. The improved convex surface is a film of plastic coated with chromium metal on its exterior surface. A multiple layered thermosetting plastic reflector support is molded onto the convex surface of the tool. The reflector support is removed from the tool and a layer of aluminum is vacuum deposited onto the interior concave parabolic reflector surface.

Abstract: A solar energy collection system is provided in which a parabolic trough is oriented by a drive mechanism to reflect the rays of the sun onto an energy collector located at the parabolic focus. The system is constructed to track the sun to maintain focusing of reflected solar radiation during daylight hours. A counterweight is employed in association with the drive mechanism to effectuate tracking and to maintain gravitational equilibrium of the reflector trough despite changes in elevation of the center of the gravity of the trough. Shock absorbers are provided which inhibit disorientation of the trough by gusts of wind, yet which allow the trough to track the sun. Coaxial construction of the solar energy collector with an evacuated sleeve of parabolic configuration positioned thereabout allows a heat collection medium to circulate in the collector, yet minimizes radiant heat loss.