IUB grants reconsideration in part to Alliant Energy's application for advance ratemaking principles
Decision gives company 30 days to file specific new information
(Des Moines) – The Iowa Utilities Board (IUB) today issued an order granting reconsideration in part to an earlier order that denied an application for advance ratemaking principles filed by Interstate Power and Light Company (IPL), a subsidiary of Alliant Energy. On November 9, 2022, the IUB denied the application after finding IPL did not meet the statutory requirements of Iowa Code § 476.53 as it did not demonstrate that the proposed Duane Arnold Solar I and Duane Arnold Solar II projects, an additional 200 megawatts of solar generation, and a battery storage project were reasonable when compared to other feasible alternative sources of electric supply.
IPL filed a motion for reconsideration or rehearing on November 29, 2022, along with providing additional testimony and exhibits. The Office of Consumer Advocate, a division of the Iowa Department of Justice, filed an objection to IPL’s motion, but stated it did not oppose a rehearing if the IUB required IPL to provide specific additional information. The Environmental Law & Policy Center and the Iowa Environmental Council filed a joint response recommending reconsideration or rehearing.
In today’s order, the IUB finds there is no basis for reversing its decision that IPL did not meet the statutory requirement for the project as a whole. However, the IUB found potential new and updated evidence could allow IPL to meet the statutory requirement that the two Duane Arnold solar facilities are reasonable when compared to other feasible alternative sources of supply and granted reconsideration to allow IPL to file that additional evidence. The order denies reconsideration for the additional 200 megawatts of solar generation and the battery energy storage system.
For the IUB to determine the reasonableness of those facilities compared to feasible alternatives, IPL will be required to file the following additional evidence:
- an updated economic analysis based upon updated costs and market prices
- an analysis of cost-per-unit of accredited capacity
- an economic analysis of IPL building and owning a natural gas simple-cycle combustion turbine, including the cost-per-unit of accredited capacity
- availability and pricing of a power purchase agreement (PPA) with NextEra Energy Resources, LLC, for generation from the Duane Arnold Solar facilities
- an economic analysis of available PPAs from sources of electric supply other than solar that IPL could enter into to meet the capacity needs
- an analysis of the Inflation Reduction Act of 2022 with regard to the potential impacts the Act will have on the electric market and other sources of supply
Other parties will have 20 days after IPL files additional evidence to file their responses. The IUB will then consider whether the additional evidence shows that the two Duane Arnold solar facilities are reasonable when compared to other feasible sources of supply.
Documents regarding the proposed IPL solar and battery storage projects are available for review in the IUB’s electronic filing system under Docket No. RPU-2021-0003.