The Multiscale Analysis Group of the Politecnico di Torino (Italy) is involved in the experimental analysis and modelling of the CHP-100 SOFC Field Unit built by Siemens Power Generation Stationary Fuel Cells (SPG-SFC). The experimental analysis of a large SOFC generator in operation is a complex task, due to the large number of variables which affect its operation, the limited number of measurements points in the generator volume, the necessity to avoid malfunctions in the real operation. As a consequence, the experimental analysis of the CHP-100 SOFC Field Unit has been developed with methods of Design of Experiments, and with a statistical analysis of the collected data. The experimental sessions have been designed in order to investigate the effect of two important operation factors in order to characterise the operation of the single sectors of the SOFC generator, and to obtain the sensitivity maps of the main investigated dependent variables. Furthermore, the main result is the estimation of the local values of fuel utilisation of the various sectors of the generator, through the combination of the experimental voltage sensitivity analysis to overall FC and an analytical model of polarisation, to outline the distribution of fuel inside the generator. Finally, the sectors of the generator, of different pedigree and position, are compared in terms of the polarization effects, showing how the local fuel utilisation and temperature affect the estimated local anode exchange current density values.