This paper deals with an analysis of several techno-economic aspects of a transport-energy system of a retail company, which is assumed to include delivery electric vehicle (EV) fleet and renewable energy sources (RES). The analysis is based on the previously proposed and validated aggregate model of delivery EV fleet and corresponding dynamic programing-based charging optimisation method. The EV fleet model is parameterised by using the data collected for the case of 10 delivery vehicles and by simulating the developed model of individual EREV (Extended Range Electric Vehicle) truck of comparable speed and torque characteristics as the existing conventional one. The potential electricity production from RES, i.e. from solar panels, is modelled by using the sun irradiance data for the particular distribution centre location. The following main relations are investigated within the paper: (i) the total operating cost of the EREV fleet, and (ii) the CO2 emissions of the EREV fleet versus the conventional vehicle fleet for different scenarios of solar panels installed.