Scientists produce the knowledge upon which inventions are built, yet most innovation policies provide incentives for firms to innovate rather than directly creating scientific human capital. In this paper, we study how direct government funding for research and development shapes the supply of scientists in the energy sector. We measure the entry of scientists as the number of energy-related PhD dissertations produced from U.S. higher education institutions and exploit quasi-experimental variation in technology-specific funding “windfalls” that emerge when Congress appropriates more or less than what the Department of Energy (DOE) requests. We find that funding for energy research indeed increases the production of scientists. We also document a positive relationship between dissertation stocks and patent flows, demonstrating the importance of producing PhD-level researchers for fostering innovation. Our empirical framework allows us to estimate the number of PhD dissertations that would have been produced under alternative funding allocations. In ongoing work, we are quantifying counterfactual dissertation production with no DOE funding post-2000, a shift of research funding from fossil to renewable energy technologies, and a reallocation of funding to maximize the production of dissertations in total across all technologies.