The rapid increase in distributed generation (DG), especially commercial and household solar PV systems in distribution networks necessitates the development of tools that provide greater insights in the behaviour of large numbers of DGs. Simulation models do not accurately capture the response of DGs to grid disturbances, and analysis of a single inverter is not representative of the behaviour of other inverters. This paper presents the development and preliminary use of an aggregation tool that allows modeling of DG response to frequency disturbances based on experimental data across a distribution feeder. By altering different renewable energy (RE) penetration levels and/or composition of inverter models in a feeder the tool can model and observe a diverse range of responses to the same grid disturbance. The tool provides preliminary insight into whether a broader simplified model of DGs is possible in distribution networks and can assist network operators with managing systems with high renewable energy penetration.