The boundary element method (BEM) is used to model short circuit electron transport in TiO2 grains in a dye-sensitized nanocrystalline solar cell. BEM is a highly efficient way of tackling any problems involving complex topography. We find that the geometry of the electrode has a noticeable effect on the short-circuit photocurrent, which is calculated from the gradient of the conduction band electron density at the anode. The modelling has established how the electron charge density distribution in the grains is distorted by the geometry of connected grains. The successful demonstration of the boundary element method here suggests that it could have applications in quite different contexts. (C) 2003 Published by Elsevier B.V.