MISO Proposes Technical Standards for Large-Load Connections as FERC Reviews Six Grid Tariffs
FERC's simultaneous review of six grid operators' large-load tariffs is pushing data centers toward higher upfront costs and stricter technical performance requirements.
MISO proposed on Friday (2026-08-28) that large electricity users must meet specific ramping and ride-through specifications before connecting to the Midcontinent grid, in a framework the grid operator says will improve its visibility into how those loads behave during stress events.5
The proposal, which MISO labels "interconnection reliability requirements," addresses a vulnerability that has grown as data centers and AI-linked facilities have crowded interconnection queues. A large industrial load that trips offline suddenly during a frequency disturbance can propagate instability across a regional grid. Requiring ride-through capability before connection is a direct response to that risk.5
FERC supplied the legal impetus. The commission voted unanimously in June (2026-06-18) to issue show-cause orders to all six regional transmission organizations and independent system operators under its jurisdiction, directing each to justify or rewrite its large-load tariff structure under Section 206 of the Federal Power Act. FERC staff said the orders address "the pressing need in the RTO/ISO regions," a territory covering nearly two-thirds of U.S. electricity load and more than 200 million people in over 30 states and the District of Columbia.1
Six grids are now running simultaneous tariff reviews. MISO's August (2026-08-28) technical filing is one of the more concrete responses to emerge. Others remain in stakeholder consultation or early regulatory proceedings, with no uniform timeline.5,1
Duke Energy's position in North Carolina shows how contested the financial details can become. The utility filed special data-center tariff rules this summer after months of pressure from clean-energy and consumer advocates who wanted Duke to create differentiated pricing for large industrial users. Duke's proposal recommends that large customers pay for at least 75% of their maximum potential energy use — below the 85% floor that advocates sought.2
Duke filed those proposals while defending a rate-increase request before state regulators at hearings that began July 7 (2026-07-07). The company lowered its initial request but still seeks a substantial increase, according to Canary Media. Asking regulators to accept a cost-causation framework for data centers at the same proceeding where residential and commercial customers face higher bills is not a comfortable position.2
The pressure on grid operators runs beyond the United States. More than 32 GW of planned data-center capacity spread across more than 1,150 projects is reshaping how power networks across Asia-Pacific handle large users, with regulators in the region imposing new requirements on reliability, flexibility, and clean-energy procurement as electricity demand strains networks, Eco-Business reported.3
In Texas, the scale of what is coming is sharper still. Peak demand in ERCOT territory could reach 120 GW by 2030, growth of more than 30% above the unofficial all-time peak recorded on July 22 (2026-07-22), though Ascend Analytics noted in a market report that supply constraints will limit how quickly that demand materializes.4
Across U.S. jurisdictions, tariff revisions are moving in a consistent direction: higher obligations before large loads can draw on grid capacity. The specific levers vary — minimum load factors, exit fees, upfront interconnection payments, and now in MISO's case, technical performance conditions embedded in the connection agreement itself. For project developers who modeled capital deployments against an assumed tariff structure, a rewrite under FERC's Section 206 authority can materially change what a project pencils out to.1,2,5
The minimum load-factor question is the one most directly in play. Duke's 75% recommendation sits below the 85% mark advocates are pushing; where state commissions ultimately land will set a reference point other utilities will cite in their own proceedings. MISO's August filing addresses the technical side of the ledger. The financial floor is still being argued, and FERC's six-grid review keeps the pressure on all of them to reach a conclusion before the commission runs out of patience with the existing structures.2,5,1