DCFlex Deliverables: Workstream 1

Cooling systems account for 30–40% of data center load yet remain one of the least-utilized resources for grid flexibility today. This report evaluates how modern cooling architectures can provide dispatchable, demand flexibility without impacting data center information technology equipment’s reliability and operation. Findings show that ride-through can be extended from seconds to tens of minutes or more through thermal mass, precooling, setpoint relaxation, and thermal energy storage (TES).

This report surveys the landscape of energy storage technologies applicable to data centers and evaluates their fit against EPRI’s Flex MOSAIC™ framework for characterizing large-load flexibility. It reviews electrochemical, mechanical, and thermal energy storage options, covering process descriptions, technology readiness, and key performance metrics. The report then maps these technologies against Flex MOSAIC’s five flexibility classes, identifying which storage types are best suited to each class’s notification, duration, and utilization requirements.

Rapid growth in artificial intelligence and high-density digital workloads is driving unprecedented demand for new data center capacity, but grid interconnection delays and transmission constraints increasingly limit the ability to secure reliable power. As a result, onsite generation, ranging from uninterruptible power supply systems and emergency backup generators to peaking units, primary power, and bridging power, has become central to data center design.

This report provides a primer on data center cooling equipment, offering both a foundational background and a current state-of-the-art review. It examines the cooling requirements and thermal standards that govern cooling system design, details modern cooling technologies, equipment configurations, industry best practices, and water use, and provides a high-level comparison across technology types. Perspectives from two major cooling equipment manufacturers are incorporated to ground the technical discussion in real-world design drivers and market context.

This report outlines the rapidly evolving permitting landscape for on-site backup and primary power at U.S. data centers, where multi-jurisdictional air, noise, water, and land-use requirements increasingly shape project feasibility and timelines. Federal emergency-use limits, state and local modeling and emissions rules, and growing community scrutiny constrain operational flexibility and drive early strategic decisions on generator classification, fleet design, siting, and fuel commitments.

This brief outlines the potential grid impacts of AI-DCs, their susceptibility to power quality disturbances, and touches on mitigation and monitoring strategies to ensure grid compatibility and operational resilience as computational demands continue to scale.

This report provides a summary of engine types for DC power generation, reviews RICE use for both primary power and emergency backup applications, and then details information gathered on RICE use for DCs from multiple engine vendors and a provider of engine units.

This publicly-accessible white paper takes a first step toward developing a common understanding of flexibility between power providers, grid operators, and data center stakeholders