As demand for electricity grows around the world, so does the need for rigorous evaluation of energy policy interventions. In this dissertation, I use large datasets and modern econometric methods to study two such policies at scale - rural electrification in India and energy efficiency subsidies in California. I find that the benefits associated with these interventions are substantially smaller than previously thought, highlighting the importance of using new techniques for causal inference in these settings. In Chapter 1, I study the impacts of grid-scale rural electrification in India, using a regression discontinuity framework. In Chapter 2, I evaluate energy efficiency upgrades in K-12 schools in California using high-frequency data a...