A detailed physical model of a hybrid photovoltaic/thermal system is p
roposed, and algorithms for making quantitative predictions regarding
the performance of the system are presented. The motivation for the pr
esent work is that solar cells act as good heat collectors and are fai
rly good selective absorbers. Additionally, most solar cells increase
their efficiency when heat is drawn from the cells. The model is based
on an analysis of energy transfers due to conduction, convection and
radiation and predicts the amount of heat that can be drawn from the s
ystem as well as the (temperature-dependent) power output. Special emp
hasis is laid on the dependence of the fin width to tube diameter rati
o. We attribute values to the model parameters, and show that hybrid d
evices are interesting concerning system efficiency as is also confirm
ed by previous experiments. Possible applications of such systems are
also proposed.