The purpose of this study is to compare two PV-energy storage systems through simulation and measurement. In the initial case, only batteries are used for energy storage, while the comparative case uses a new battery- ultracapacitor hybrid. Simulation of the performance of the two energy storage systems is done using VisSim, with the future goal of using TRNSYS, a modular FORTRAN-based energy modeling software. A model of the ultracapacitor is being made that incorporates this frequency dependent behavior. This model is compatible with TRNSYS using which the battery-ultracapacitor hybrid system will be simulated. The testing will be performed on stand-alone PV systems and compared with simulation results. The results of the tests will enable us to directly compare measured system performance to modeled performance. The performance parameters compared are load response and peak power delivered for both the systems.