Renewable energy mini-grids are a key technology for extending electricity access to over 500 million people worldwide. Yet, for such a critical infrastructure, the mini-grid sector is far from standardized and faces several challenges. This course takes a deep dive into the rapidly evolving technologies, business models, policies, and project development approaches that are driving innovation in rural electricity access. Students learn the context of energy poverty, how limited energy access underlies numerous development challenges, and the various current approaches for rural electrification. The course then focuses specifically on renewable energy mini-grids, introducing the technology stack — generation, power conversion, energy storage, distribution, and metering — their different architectures and business models for service delivery. Students learn specific tools and methods for the mini-grid project development process, including feasibility studies, demand estimation, risk assessment, and project financing. Students also learn participatory planning and community engagement techniques that align project design with community expectations and increase community agency. The course draws on case studies and contributions from active practitioners, particularly from Sub-Saharan Africa and South Asia. Students completing this course come away with a deep understanding of mini-grid technology, the opportunities and challenges around rural energy access, and the latest tools and methods for mini-grid project development.