Sustainable energy systems for data infrastructure leverage renewables, waste heat recovery, energy storage, and AI-driven energy optimization to power and cool data centers. This reduces reliance on fossil fuels and improves energy efficiency. Benefits include lower operational costs, minimized environmental impact, and improved grid resilience. Leaders such as Google, Amazon Web Services, and Switch are deploying solar, wind, and hydropower, alongside innovations like liquid cooling and microgrids. With supportive policies and high patent activity, these systems are becoming central to sustainable digital transformation.