Presently, the analysis of the impact of the thermopower plants on the environment as a result of harmful gas emissions is done individually for each type of gas. There is no general methodology to treat this problem globally, that is, to take into consideration all the cumulative effects of the respective gases and also to make the necessary analysis from the point of view of estimating all the pollution effects in correlation with the useful energy produced. In this paper we present, for the first time, a methodology which offers the possibility to treat as a whole, globally, this efficiency problem of the thermopower plants regarding their impact on the environment in two aspects: first, regarding the harmful gas emissions in the atmosphere, and second, regarding the quantities of the corresponding emissions in relation to the unit of useful energy produced. To achieve this, we generated the model described herein.