This study investigates alternative equity-based financing models and proposes a waqf-owned (that could also be called philanthropy-, endowment-, trust-, foundation-, and third sector-based) financial intermediary (WOFI). We do so by developing the agent-based model and scenario-based computer simulations for financing solar powerplants. For this purpose, we redesign a waqf-based financing system and analyze the changes in wealth inequality, capital pooling, and social prosperity for a future time frame. As a proof-of-concept, the simulation results show that for the given case study, the proposed WOFI reduces wealth inequality dramatically, whereas conventional debt-based financing models raise inequality. Besides, restructuring the waqf-based financial intermediaries also enables the capital pooling essential for large projects and absent in the conventional waqf system. In short, this study proves that waqf-based institutions have a remarkable potential to contribute towards sustainable development goals by taking account of long-run social implications, economic growth, and environment-friendly projects.