As grid constraints, carbon mandates, and AI workloads converge, data centers are under pressure to deliver more power with fewer emissions and greater predictability. This roundtable will explore how operators, utilities, and infrastructure partners are addressing the realities of sustainable energy sourcing in 2025. From on-site generation and long-duration storage to the rise of strategies involving microgrids, PPAs, and/or nuclear pilots, the discussion will surface the tradeoffs between speed-to-power and decarbonization and how “clean firm” energy is being defined in practice.