Abstract: A solar heating panel having a curvilinear flow passageway through which a fluid flows to be heated by solar energy, comprising a top sheet having a plurality of upwardly protruding convex upper-portions shaped to reflect a portion of incident energy from the sun to adjacent upper-portions, and a bottom sheet sealingly engaging the top sheet and having a like plurality of upwardly protruding convex lower-portions which underlie a corresponding one of the upper-portions, and protrude upwardly into such upper-portions of the top sheet thereby defining a hollow space therebetween which has a crescent-shaped cross-section, wherein the hollow spaces thereby formed are interconnected to form the flow channel. As a further refinement, undulations, protuberances or depressions may be further provided along the length of the flow channel to introduce turbulence in the fluid flow to thereby increase the rate of heat exchange between the solar heating panel and the fluid.