The porous-medium flat-plate solar collector is an interesting alternative to conventional fin-and-tube designs if higher pumping power requirements do not offset collector efficiency gains. In this paper, complementary to a transient two-phase heat transfer study where Darcy's law had been used, a non-Darcy flow equation and the convection-conduction heat transfer equation are solved numerically. The coupled fluid flow and heat transfer mechanisms are analyzed for a porous-medium solar collector, and its high-performance efficiency is compared with advanced tubular-type collectors.