Abstract: A solar panel has a series of channels through which water or other fluids may flow for exposure to and heating by solar radiation. Common to all the channels are inlet and outlet manifolds through which, respectively, the water is directed into and discharged from the channels. Construction of the panel is simplified and is rendered economical by fashioning of the same from a pair of superposed, inexpensive metal sheets, as for example roofing tin. The sheets are readily preformed with the manifolds and channels, in such fashion that when the sheets are connected along their peripheries by means of mechanical expedients well known in the sheet metal art, the several channels are automatically defined between the sheets, and are further automatically brought into communication with the inlet and outlet manifolds.