Recent modelling work of the energy distribution throughout a local small-scale combined energy generation system (CEGS) has been based on the Dutch SOMES code. This is presently being revised at Loughborough University, to reflect more closely the operating conditions of the CEGS and to facilitate overall control optimisation. Extensive data monitoring equipment has been installed, to provide validation data for the model and to facilitate real-time analysis of the system. This paper presents the operational characteristics of the CEGS and explains progress with the system modelling.