Vijay Modi is a professor in the Department of Mechanical Engineering at Columbia University and a member of the Earth Institute faculty. His areas of expertise are energy resources/access, energy planning for access and renewable integration, demand estimation and role of novel payment systems in breaking barriers to upfront costs. His laboratory, the Quadracci Sustainable Engineering Lab (QSEL), has been responsible for innovations such as a low-cost lead-acid charge/discharge circuit for solar lanterns (2005), fully digital pay-as-you-go minigrids that have been continuously operating as pilots since 2011, battery-less PAYG smallholder irrigation systems (2013-15) and widely used tools such as “Network Planner” for making technology choices under demographic, demand and geographic variations. His recent work has been on energy infrastructure design and planning; solar energy; energy efficiency in agriculture, and data analytics spanning from urban settings to remote rural settings. He is currently working to understand how energy services can be more accessible, more efficient and cleaner and examining minigrids in the context of energy efficiency.