This thesis describes full-scale and wind tunnel investigations aimed at determining the forced convection heat loss from flat plate solar collectors to the wind as a function of wind speed, type of supporting structure, and collector location on that structure. Associated with these investigations was an examination of the relevant data and analyses in the literature, including a detailed investigation of the relation currently used in estimating the heat loss term in question. The fullscale data to a good degree corroborated the wind-tunnel results. Thus, some confidence is expressed in the major result of the study: a series of design relations based on the wind tunnel data.