In this research, we analyse how project risk allocation strategies impact the volume of private investment in renewable energy projects with the participation of both the public and private sectors. To this purpose, we analyse a sample formed by 2215 projects performed in 73 developing countries in the period 1997-2019 involving the following technologies: solar, hydro, wind, waste, biogas, biomass, and geothermal. Our findings reveal that those projects performed through governance schemes in which the private partner takes more project responsibilities attract more private money. Additional drivers for attracting private investment at the project level and institutional level are found. Furthermore, we reveal that the transference of project risks to the private partner emerges as a very relevant project feature that interacts with some of the project and institutional factors, revealing both complementary and substitution effects. The significance of this research extends beyond academia, since there are factors influencing private investment that can be controlled by various stakeholders in projects (such as policymakers, private investors, and project managers). Understanding their impact, significance, and interaction effects-factors that sometimes moderate or accentuate private investment-is crucial. The identified patterns illuminate optimal risk allocation practices, offering practical insights to enhance the effectiveness and sustainability of projects.