•Proposal of a novel cogeneration of power, cooling, and heating using solar energy.•Utilization of zeotropic mixtures for efficiency improvement.•Evaluation of the system performance from the energy and exergy viewpoints.•Highest exergy and energy efficiencies of 20.26% and 15.81%. In this study, a novel power, cooling, and heating cogeneration system was devised. In the proposed system, parabolic trough solar collectors were used as the primary energy source. Also, the zeotropic mixtures were employed as the working fluid of the dual-pressure organic Rankine and ejector refrigeration cycles for efficiency improvement. The system was analyzed from the energy and exergy viewpoints in MATLAB software using library data of Refprop and Coolprop toolboxes for obtaining the thermodynamic properties of working fluids. The best performance of the system was obtained under some circumstances, including a constant rate of solar radiation (DNI) as 1000W·m-2 and using 410 solar collectors with an area of 28976m2, and employing Pentane (0.5)/Trans-2-Butene (0.5) and Isobutane (0.2)/Isopentane (0.8) as the zeotropic working fluids in the dual-pressure organic Rankine cycle and the ejector refrigeration cycle. In these conditions, the electrical power, cooling load, and heating capacity were calculated by 4082.6kW, 51.52kW, and 1 616.4kW. Also, total exergy loss of the system was obtained by 22.19MW, and the highest exergy and energy efficiencies were computed by 20.26% and 15.81%, respectively.