The Electric Power Research Institute on March 23 said it is launching Flex MOSAIC, a uniform flexibility classification framework for large electric loads, developed through its DCFlex initiative in collaboration with more than 65 utilities, system operators, regulators, hyperscalers, and technology providers.
The voluntary framework establishes a shared, credible way to define flexibility from large loads -- particularly data centers -- based on the magnitude, timing, duration, and frequency of their response. By enabling a common understanding of what flexibility a load can deliver, the framework may shorten interconnection timelines, improve grid planning confidence, and accelerate access to power without compromising reliability or affordability, EPRI said.
"Greater transparency and a consistent framework benefit all parties. Utilities and system operators gain greater confidence in integrating large, flexible loads while maintaining reliability. Meantime, developers can design facilities with flexibility in mind—unlocking faster, more predictable grid connections and expanding options for where projects can be sited," it said.
“As demand from AI and data centers grows at unprecedented speed, flexibility is becoming the third leg of the speed-to-power stool, alongside generation and transmission,” said EPRI President and CEO Arshad Mansoor. “This framework allows everyone — utilities, regulators, and large load developers — to have common language about flexibility and to trust what that language means. That shared understanding is essential to moving faster while maintaining reliability.”
The framework defines flexibility through practical performance characteristics, including how quickly a load can respond, how long adjustments can last, and how much power can be reduced or shifted. These characteristics are organized into a small set of uniform flexibility classes that utilities, system operators, and data centers can apply consistently across regions.
Initial framework participants include (public power utilities in bold):
• Alliant Energy
• Arizona Public Service
• California ISO
• Carrier
• El Centro Nacional de Control de Energía
• Compass Datacenters
• Constellation Energy
• DTE Energy
• Entergy
• Exelon
• Georgia Transmission Corporation
• Google
• Honeywell
• Independent Electricity System Operator (IESO)
• ING
• Jenbacher
• Korea Power Exchange
• KPMG
• LG Pado
• Lincoln Electric System
• Lower Colorado River Authority
• Meta
• Midcontinent Independent System Operator
• Nebraska Public Power District
• NERC
• NVIDIA
• Octopus Energy
• Portland General Electric
• PSEG
• Rayburn Electric
• Salt River Project
• Siemens
• Southern Company
• Southwest Power Pool
• United Power
