A different Mnx(x= 0.03, 0.05, 0.07) doped on CuO1-x has been successfully synthesised by a co-precipitation method by maintaining a pH-12. The nature of Mn doped CuO nanoparticles has been characterized with the help of X- Ray Diffraction (XRD). The Mn in the lattice sites of CuO gives the monoclinic crystal structure with C2/c space group which has been confirmed through JCPDS card no: 05-0661. The morphology variations with Mnx doping have been examined with the help of field emission scanning electron microscope (FESEM) and Energy Dispersive X-Ray Spectroscopy (EDS). Additionally, band properties have also been noticed via Ultraviolet-Visible (UV) Spectroscopy. The band gap of material has been calculated as 2.39 eV, 1.96 eV and 2.25 eV for energy harvesting modelling through MATLAB with temperature difference behaviour of material. The thermodynamic modelling has been used for energy harvesting application with the help of MATLAB and the Seebeck coefficient has been calculated for thermoelectric modelling of CuO-Mnx.