High-efficiency bulk heterojunction (BHJ) organic solar cells with power conversion efficiencies of more than 5 % can be fabricated using the green solvent 2-Methyltetrahydrofuran (2-MeTHF). The active layer comprise a blend of a molecular semiconductor donor with intermediate dimensions and the soluble fullerene derivative [6,6]-phenyl-C61-butyricacidoctylester (PC61BC8). Absorption spectroscopy, atomic force microscopy, and grazing incidence wide-angle X-ray scattering reveal no significant modification of morphology when processing from 2-MeTHF compared to processing from chloroform. Space Charge Limited Current (SCLC) hole mobilities of the optimized solar cell conditions showed no difference in the transport properties between the 2-MeTHF and chloroform processed systems. These results show that green solvents can be excellent alternatives for large-area printing of high-performance organic photo voltaics (OPVs) and thus open new opportunities for sustainable mass production of organic solar cells and other optoelectronic devices.