Energy Alerts impact central and western Iowa

Energy Alerts impact central and western Iowa

A map of temperatures below 0 degrees Feb. 14-16 (dark blue) and SPP’s 14-state balancing authority area (red).

Feb. 18, 2021 - Utilities across the Midwest, including Midland Power Cooperative’s power supplier Corn Belt Power Cooperative, were called upon to implement load curtailment measures to some meters on Feb. 15 and 16. Corn Belt power is a member of a regional transmission organization (RTO) known as Southwest Power Pool (SPP). The events of this week were unprecedented as extreme and prolonged arctic weather significantly impacted the RTO’s 14-state footprint, stretching from Canada to northern Texas. Regional power supply energy emergency alert declarations were proclaimed as unprecedented and historic energy demand was placed on the system.

Many electric utilities across the country are members of one of nine RTOs and independent system operators (ISOs), also referred to as power pools. These federally regulated entities work on a regional scale to coordinate, control, and monitor supply and demand on the electric grid. RTOs do not own the power grid, but they work as “air-traffic controllers” of the grid to ensure reliable supplies of power, adequate transmission infrastructure and competitive wholesale electricity prices on behalf of their members.

SPP issued Energy Emergency Alert (EEA) Level 2 and Level 3 orders to its member utilities across several states on Monday through Wednesday, calling for high levels of electric load reduction/curtailment to match available supply. To put it simply, there was not enough available generation/supply to meet this exceptionally high electric demand. This is the first time in its 80-year history SPP issued an EEA Level 2 or Level 3 warning.

Power outages caused by electric load curtailment in north-central Iowa included:

  • Monday, Feb. 15, 5 megawatts of load was curtailed for approximately 45 minutes around the noon hour. Approximately 1,500 accounts were without power. None of these were Midland Power members.
  • Tuesday, Feb. 16, 24 megawatts of load was curtailed between 6:45 – 10:15 a.m.  Approximately 12,500 accounts were without power at some point during the event, including approximately 1,600 Midland Power consumers.

These outages occurred without much advanced warning, as SPP manages electric supply and demand minute-by-minute in real time. Corn Belt Power Cooperative had minutes to shed specific electric load levels as they complied with Level 3 orders.

Outages and load curtailment measures are necessary to protect the entire SPP power grid. If electric generation cannot keep up with electric demand, grid reliability can be severely compromised. In this worst-case scenario, power plants across the SPP footprint are at risk of cascading outages that would leave tens of thousands of electric consumers in the dark for hours, possibly even days. Thanks to the efforts of utilities across the SPP footprint, the electric grid experienced only minor levels of service disruption.

In addition, electric consumers are continuing to be encouraged to practice energy conservation measures such as turning down thermostats, covering drafty windows, avoiding use of large appliances like clothes washers, dryers, and ovens especially during times of peak demand such as early in the morning or late in the afternoon.

As our cooperative emerges from this week and begins to experience decreased strain on the system due to warming temps and more moderate weather forecasts, it is anticipated that there will be less demand from generation resources.


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