Eigenvalues of a graph are the eigenvalues of its adjacency matrix. The multiset of eigenvalues is called the spectrum. There are many properties which can be explained using the spectrum like energy, connectedness, vertex connectivity, chromatic number, and perfect matching etc. So it is very useful to calculate the spectrum of any graph. The energy of a graph is the sum of the absolute values of its eigenvalues. In this paper we calculate the energy of some grid based networks. © 2012 IEEE.