The long-term annual thermal energy delivery per unit of collector area of commonly used collector types and configurations, for a range of operating temperatures, are calculated for representative locations in Zimbabwe. A well-known model found in the literature is the basic tool of analysis, the only modifications being, the use of a locally-derived correlation of the monthly average diffuse fraction of hemispherical radiation to the monthly average clearness index, and the use of temperature-dependent collector heat loss coefficients. The results are presented as plots of annual specific thermal energy output against collector receiver temperature gain (T-r-T-a). The results, though founded on a number of simplifying assumptions on some collector parameters, provide a sound basis for the economic evaluation of solar thermal applications in Zimbabwe.