A Simulation model for simulation of a single solar cell and two solar cells in series has been developed using Simelectronics (Matlab/Simulink) environment and is presented here in this paper.  A solar cell block is available in simelectronics, which was used with many other blocks to plot I-V and P-V characteristics under variations of parameters considering one parameter variation at a time. The effect of variation of parameters such as series resistance, Rs, shunt resistance Rsh, diode parameters: diode saturation current, Is and ideality factor, N, could be seen on the characteristics of a single solar cell. Effect of two environmental parameters of temperature and irradiance variations could also be observed from simulated characteristics.  Matlab coding has been done to find the maximum power output, Pm, and voltage at maximum power output, Vm, of a single solar cell and two solar cells (in series) under different values of parameters.  The Pm and Vm values are tabulated here in this paper for variation of one parameter at a time, considering the diode parameters: Is and N, resistances: series and shunt, temperature and irradiance.