More renewable energy may complicate regional power grid: MISO assessment

Wind and solar generation are projected to span 60 percent of the regional energy capacity by 2041 — which could make it more complicated to plan and operate the power grid, according to a report released this week by the Midcontinent Independent System Operator, or MISO.

MISO manages Iowa’s energy on the power grid along with that of 14 other states and a Canadian province. It is tasked with making sure the right amount of electricity is generated across its north, central and south zones. That energy can then be sold and transmitted between its member utilities that distribute the power to their customers.

MISO’s 2022 regional resource assessment evaluated how its member utilities’ energy portfolios are evolving — based on any plans announced as of Jan. 31 of this year — and any effects on energy reliability, affordability and sustainability in the next 20 years.

It also modeled additional resources that members could build to help accommodate energy needs.

The region historically sported a diverse energy portfolio with relatively consistent energy generation and demand.

The assessment discussed how today’s transforming energy market — influenced by changing economics, environmental regulations and more — is making the regional portfolio more saturated with renewable energy.

In the next two decades, MISO utilities are planning to add more than 30 gigawatts of installed capacity — the maximum energy a resource can theoretically produce under ideal conditions — of mostly wind and solar projects, according to the assessment.

Within the next five years alone, MISO could receive as much as 30 percent of its energy from wind and solar generation.

However, wind and solar energy are dependent on regional weather conditions. That makes their output less reliable than non-renewable generation that can operate at any time.

As a result, renewable energy is typically assigned a lower expected energy output.

As wind and solar energy grows, contributions from coal and natural gas are expected to drop. So even with more planned investments in energy generation, the amount of energy MISO can expect to manage will drop at least 10 gigawatts in the next two decades, complicating widespread energy distribution.

“Before, planning was a relatively well-understood task, akin to arranging generally uniform building blocks,” the assessment said. “Now planning is far more complicated, like assembling a jigsaw puzzle with many disparate pieces.”

Renewable energy additions are largely motivated by state and company decarbonization goals, the assessment said. Emissions in the territory are expected to drop 65 percent by 2030, compared to 2005 levels.

They should reach an 80 percent reduction by 2041.

The region’s existing and planned energy generation should meet anticipated energy needs for the next four years — but only barely. If energy demands surpass expectations or if plant retirements are accelerated without replacement generation, the risk of energy shortfalls will increase, according to the assessment.

By 2027, anticipated energy generation may not be enough to reach forecast demands. MISO modeled that member utilities may need to build more than 100 gigawatts of new energy generation within the next 10 years to achieve their energy needs while maintaining grid reliability — “an unprecedented volume for the MISO region,” the assessment stated.

However, MISO couldn’t consider utility plans that haven’t been announced yet in its assessment, which could increase the projected energy capacity.

“This study, like all MISO studies, is sensitive to the assumptions made and limitations of the data available to shape assumptions,” the assessment stated. “One such limitation is visibility into company plans.”

In the face of more renewable generation, MISO is identifying attributes that should be preserved to supplement energy reliability. For example, the assessment recommended adding more resources that can produce on-demand energy.

It also highlighted how using battery storage to hybridize solar generation can improve energy contributions.

Emerging technologies — such as green hydrogen and smaller nuclear reactors — may aid the power grid in the next two decades. But it’s hard to predict when these resources will be available commercially.

How might Iowa be affected?

Although MISO’s overall territory is projected to meet the necessary capacity within the next four years, energy demands for its Region 3 — which is comprised of Iowa and parts of Illinois and Minnesota — are projected to be greater than the resources available next year.

During these situations, regions can lean on their neighbor’s energy. An intricate web of contracts gives MISO access to generators elsewhere that can provide needed power.

Over the next 20 years, Region 3’s energy demand is expected to increase by 1.6 gigawatts. At least 0.8 gigawatts worth of its coal-fired and natural gas-fired fleet will retire by 2030.

In the meantime, around 2.5 gigawatts of wind energy, solar energy and battery storage is expected to be added.

MidAmerican Energy and Alliant Energy have announced plans to expand their renewable energy generation in Iowa.

Alliant’s Clean Energy Blueprint has mapped hundreds of new megawatts of renewable energy generation in the state for the coming years.

MidAmerican Energy has, too, although some environmental groups, tech companies, manufacturers and a lawyer in Iowa said they are skeptical of the plans without seeing more data.

In light of its Lansing, Iowa, coal-fired power plant closing by the end of this year, Alliant previously told The Gazette that energy reliability shouldn’t be compromised with the addition of more renewable energy thanks to natural gas and battery storage that can help supplement solar and wind.

Brittney J. Miller is the energy and environment reporter for The Gazette and a corps member with Report for America, a national service program that places journalists in local newsrooms to report on under-covered issues.

Comments: (319) 398-8370; brittney.miller@thegazette.com