Solar energy has been used since the beginning of time and is vital to all living things. In addition to solar energy being a constant resource, heat and electricity are other forms of energy that can be made from solar energy. Technology allows solar energy to be converted into electricity through solar thermal heat. The main advantages of solar energy are that it is clean, able to operate independently or in conjunction with traditional energy sources, and is remarkably renewable. Nanofluid-based direct solar receivers, where nanoparticles in a liquid medium can scatter and absorb solar radiation, have recently received interest to efficiently distribute and store the thermal energy. The objective of the present work is to investigate theoretically the effect of copper nanoparticles in the presence of magnetic field on unsteady non-Darcy flow and heat transfer of incompressible copper nanofluid along a porous wedge due to solar energy. It is of special interest in this work to consider that the similarity transformation is used for unsteady flow. Copper nanofluid flow over a porous wedge plays a significant role and absorbs the incident solar radiation and transits it to the working fluid by convection. (C) 2013 Elsevier Ltd. All rights reserved.