This paper presents modeling and simulation of microturbine (MT) models to analyze its load following performance as distributed energy resource (DER) with general as well as critical priority loads. Two different models of MT were considered for performance analysis. The first model consists of speed governor, acceleration control, and temperature control blocks while the other is GAST model of MT. The system comprises of a synchronous generator and a MT coupled to it. Simulations are carried out in islanded and grid-connected mode of the system to observe its behavior when supplying customerpsilas variable loads. The load following characteristics is observed and validated for this MT-synchronous generator model in Matlab-Simulink environment with power system block sets. This is applicable with combined heat power (CHP) generators both with general fuel as well as bio-fuels. The use of bio-fuels is very much promising for generating green power preventing green house gas emissions for fighting against global warming. But it may take some time to be in the market place for its commercial use.