A reciprocating solar engine includes a) a seesawing platform having a central fulcrum support upon which to reciprocally rotate the platform; b) a first container located on the platform on one side and a second container located on the other side of the platform; c) a solar reflector located adjacent each container; d) a connecting tube connecting the first and second containers; e) an evaporative fluid contained within at least one of the containers; f) a roof above the platform with a window located above each of the containers; g) shutter devices at each of the windows; and b) shutter device controls to activate the shutter devices to present alternating exposure of sunlight and shading at each of the containers to effect reciprocal movement.