Abstract Renewable energy sources are becoming more and more vital around the word from the last decades, due to the limited reserves of fossil fuels and environmental matters. Starting from this consideration, this paper investigates the possibility to provide a new urban agglomeration in Naples (Italy) with power, heat and cooling, by a modern trigeneration plant. The study was performed for thermal and refrigeration needs of the planned settlements. The analysis was carried out considering two alternative schemes, both based on internal combustion engines: in the first system solution the engines are fueled by natural gas, in the second one, by renewable vegetable oils. Energy and economic evaluations were carried out in order to assess the pay-back period of the investment for the two different systems: the plant configuration based on a renewable energy source was more convenient and profitable. For this power plant solution, finally, an environmental analysis was performed in order to assess the impact of this power system on the territory surrounding the trigeneration plant: the effect on local air quality state was minimal. This environmental analysis was carried out using the Gaussian dispersion model ISC, that determines the pollutant concentrations due to a point emissive source.