This report is part of the evaluation work carried out at Ecole Centrale on central receiver plants. THEMIS system peformance is evaluated with emphasis given to energy production. The daily energy production is established on the basis of both plant modelization and actual plant production results. This analysis is performed at different levels of the system: receiver output, salt loop output, turbine-generator output and net plant output. In each case an input-output characteristic curve is established, considering the daily direct normal solar radiation as the input of the system. This input is defined for a given site by a meteo distribution, i.e. a yearly distribution of the daily direct normal solar radiation. The yearly plant production is then deduced by adding over the year the daily production calculated by combining the input-output characteristics with the meteo distribution of the considered site. Using this method, the energy production of THEMIS is estimated, assuming different meteorological conditions. The influence of the meteorological conditions and other parameters, on the plant output is finally discussed. 15 refs., 61 figs., 41 tabs.