Alliant accepts Iowa Utilities Board order to build new Marshalltown power plant

Alliant Energy's Interstate Power and Light utility subsidiary on Tuesday filed a notice accepting the proposed Iowa Utilities Board decision and order issued Nov. 8 for the Marshalltown Generating Station.

The decision and order will become permanent on Nov. 25 unless the Iowa Utilities Board decides to appeal it or an appeal is filed by any party involved in the regulatory approval process.

In the filing, Interstate Power and Light of Cedar Rapids affirms its plan to construct the plant and cover costs of related high-voltage transmission upgrades and allowance for funds used during construction within the $920 million cost cap established in the proposed order.

Iowa Utilities Board Chairwoman Libby Jacobs issued the proposed decision conditionally approving an electric generation certificate and establishing advance rate making principles for the Marshalltown power plant.

The order also contains cost recovery factors to be included in a future rate case, including an 11 percent rate of return on equity and a depreciation lifetime of 35 years for the company to recover its investment.

The Iowa Utilities Board approval is conditional on the company attaining other state and federal permitting approvals necessary to construct and operate the natural gas-fired generating station.

On Monday, the company received a proposed decision and order approving the needed pipeline construction to serve natural gas to the Marshalltown Generating Station, which is one of the key approvals needed before construction begins.

Interstate Power and Light  must still get approval of several permits on the local, state and national levels, including air and water permits.

Pending obtaining all regulatory approvals, Interstate Power and Light expects to begin construction in 2014 and begin operations in 2017.

The proposed plant is part of Alliant Energy's long-term energy plan that includes about $440 million in upgrades to existing power plants by reducing air emissions, a proposal to extend its nuclear power purchasing agreement from the Duane Arnold Energy Center, and more investment in renewables and energy efficiency.