homepage logo


Energy alerts impact central and western Iowa

By Staff | Feb 21, 2021

From Iowa Lakes Electric


Utilities across the Midwest,

including Corn Belt Power

Cooperative, Iowa Lakes Electric

Cooperative’s wholesale power

supplier, was 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 do

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.

Corn Belt Power’s times of curtailment included:

On Monday, Feb. 15 @ 12:15 p.m., SPP called for Corn Belt Power to curtail 5 megawatts of load for approximately 45 minutes. Of the approximately 1,500 accounts who lost power throughout the Corn Belt Power system, 279 were member-owners from Iowa Lakes Electric Cooperative lasting 33 minutes.

On Tuesday, Feb 16 between 6:45-10:15 a.m., SPP called for Corn Belt Power to curtail 24 megawatts of load. Of the approximately 12,500 accounts who lost power throughout the Corn Belt system, 3,392 were member-owners of Iowa Lakes Electric Cooperative. Of the seven substations Corn Belt Power de-energized, all but one was re-energized in just over one hour. There was a switch failure in one of the seven substations that kept the substation offline for just over two hours.

These outages referred to as rolling blackouts, 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 member-owners in the dark for hours, possibly even days. Thanks to the efforts of Corn Belt Power, as well as several other utilities across the SPP footprint, the electric grid experienced only minor levels of service disruption.

Corn Belt Power collaborated with its member cooperatives as well as state and regional partners to react and respond to the ever-changing EEA alerts impacting central and western Iowa. In addition, electric member-owners 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.