Iowa Consumer Advocate Pushes for Scrutiny of Alliant’s $3.2 Billion Gas Plant Plans: Authorities confirm

Iowa’s Office of Consumer Advocate has formally challenged two proposed natural gas power plants from Alliant Energy’s Interstate Power and Light, filing a request for additional information and a public hearing on September 11. The filing takes aim at Riverhawk, a proposed 1,200-megawatt gas turbine facility planned for Cerro Gordo County next to the existing Emery Generating Station, and raises concerns about a second project, Morgan Valley, a 720-megawatt plant west of Cedar Rapids featuring three simple-cycle combustion turbines. Together, the advocate estimates the two projects would carry construction costs ranging from $2.1 billion to $3.2 billion, a figure that does not include ongoing fuel, maintenance, and financing expenses. Alliant has not publicly responded to that cost estimate, according to Iowa Capital Dispatch.

The central dispute involves when regulators should weigh whether the projects are actually needed and financially sound for customers. Iowa’s generating certificate process, which applies to power plants of at least 25 megawatts, is currently reviewing Riverhawk’s application. The consumer advocate, joined by Clean Energy Districts of Iowa and the Iowa Business Energy Coalition, argues that the certificate proceeding is the right moment to examine need, cost-effectiveness, and customer affordability — and that the commission should reject the certificate if Alliant cannot demonstrate the project clears those bars. Alliant disagrees, contending that prudency and cost questions belong in a separate rate case held after a certificate is granted. The company also asked regulators to waive a hearing entirely. The advocate warns that delaying this scrutiny risks allowing construction commitments to advance before any meaningful alternatives review takes place. Alliant’s two proposed plants are part of a broader buildout: the 720-megawatt Bobcat Energy Center in Marshalltown is already under construction and expected online in 2029, meaning all three projects combined would add roughly 2,640 megawatts to the grid if approved and completed. Alliant has pointed to surging electricity demand as justification, reporting approximately 3.4 gigawatts of contracted data center load across its system as of April 2026 and projecting 60 percent load growth by 2031. Morgan Valley is expected to begin operating in 2030, with Riverhawk targeted for 2031. Alliant says both plants would serve the broader grid during high-demand periods and that current customers would not bear the cost of capacity built to serve large new users. Critics, however, argue that confidential rate agreements with data center customers — such as a deal with QTS in Cedar Rapids — make it difficult to verify whether those large users are fully covering the costs of new generation.

“The consumer advocate says the commission should deny the certificate if Alliant cannot demonstrate that its proposal is cost-effective,” according to the September 11 filing, which also calls for a resource evaluation study comparing Riverhawk against alternative generation options.

The outcome of this regulatory fight carries significant financial implications for Iowa ratepayers. Although the $3.2 billion upper-end estimate does not represent a charge already passed to customers — project costs require a separate rate proceeding before they can enter utility bills — the advocate’s core argument is that waiting for that later review may come too late to meaningfully influence decisions once construction is underway. Simple-cycle gas turbines, the technology proposed for both plants, can ramp up quickly to meet demand peaks, but federal energy data indicate they consume more fuel per unit of electricity generated than combined-cycle alternatives, making long-term operating costs sensitive to natural gas prices. With Iowa already generating 63 percent of its electricity from wind in 2024 — the highest wind share recorded by any state that year — the question of how much new gas capacity the grid actually requires, and who should bear the cost of building it, sits at the heart of the proceeding now before state regulators.