Post: MISO alerts…explained

MISO alerts…explained

During extreme summer heat or volatile winter weather, the Midcontinent Independent System Operator (MISO) issues a series of notifications that escalate as conditions tighten.

Weather Alert

MISO issues a Hot, Cold or Severe Weather Alert for situational awareness when weather conditions may affect generation or transmission capacity. It’s an early flag that conditions bear watching, rather than a call to action.

Conservative Operations

This is also a situational-awareness notification, but it also provides an early indication that system conditions may require emergency procedures. When Conservative Operations is declared, non-critical equipment maintenance is suspended or, in some cases, returned to service. Members are asked to review outage plans and work out which planned maintenance or testing can be postponed.

Capacity Advisory

A Capacity Advisory tells MISO participants that, based on projected system conditions and capacity levels, there may be a need in the coming days to bring additional generating units online.

EOP events

Beyond these advisory-level notices sits MISO’s emergency operating procedure structure, which is built around escalating Emergency Operating Procedures (EOPs): advisories, alerts, warnings, and events.

If conditions continue to tighten, MISO can declare a Max Generation Event. From June 1, 2026, MISO simplified this structure, consolidating what had been a five-step framework into three steps to align more closely with the NERC Energy Emergency Alert (EEA) levels.

Energy Emergency Alert levels

When electricity demand is greater than the supply, MISO begins emergency operations to prevent an uncontrolled system-wide outage. There are three levels of Energy Emergency Alerts:

• EEA 1: MISO can no longer meet projected electricity demand and operating reserve requirements without additional measures. This is the first level of emergency action
• EEA 2: operating reserves continue to decline and additional actions are needed to balance supply and demand. MISO operators can access emergency generation resources not available under normal conditions, seek emergency energy from neighbouring grids where available, and implement further demand-reduction procedures. A public appeal asking utilities to encourage voluntary conservation can be issued at this stage
• EEA 3: this is reached when MISO can no longer maintain minimum contingency reserves and co-ordinated load interruptions may be required as a last resort

Looking ahead

NERC’s 2026 Long-Term Reliability Assessment, released in January, places MISO among the areas facing heightened resource-adequacy concern over the medium term. It projects that MISO could move from elevated to high risk by 2028 as demand from data centres and electrification accelerates.