Regional Transmission Service Rider Amended Filing

Strategic Insights -

Des Moines residents can expect changes to their electric bills starting June 2025, as Iowa Public Utilities Commission has approved an amendment to the Regional Transmission Service Rider (Rider RTS) tariff. The amendment, filed by Interstate Power and Light Company on May 19, 2025, corrects errors in the 2024 reconciliation and revises RTS rates for various customer classes. Customers can expect a decrease in their RTS rates, with a "Regional Transmission Service Refund" included in their June 2025 bills.

Key Takeaways:

  • The Regional Transmission Service Rider (Rider RTS) tariff has been amended to correct errors in the 2024 reconciliation.
  • Interstate Power and Light Company (IPL) has identified errors in the amount attributed to the interest related to the 2016-2020 wholesale expense true-up, totaling $376,258.30, which was mistakenly included in the 2024 reconciliation.
  • The total under-collection for 2024 is $1,017,286.32, including the interest discussed above, rather than the $1,362,110.60 under-collection originally filed.
  • RTS rates for various customer classes have been revised, with a decrease in rates for Residential, General Service, Large General Service, Large General Service-Supplementary, High Load Factor, Lighting, Standby, and other customer classes.
  • A "Regional Transmission Service Refund" has been included in the RTS rates for all customer classes, effective June 1, 2025.
  • The Federal Energy Regulatory Commission has approved a refund of a portion of the costs transmission providers charge customers.
  • The revised RTS rates for June 2025 are as follows:

+ Residential: $0.04067 per kWh (decrease from $0.04077 per kWh)

+ General Service: $0.03202 per kWh (decrease from $0.03217 per kWh)

+ Large General Service: $10.68 per kW (decrease from $10.72 per kW)

+ Large General Service-Supplementary: $6.43 per kW (decrease from $6.49 per kW)

+ High Load Factor: $11.90 per kW (decrease from $11.93 per kW)

+ Lighting: $0.03504 per kWh (decrease from $0.03533 per kWh)

+ Standby: $7.99 per kW (decrease from $8.08 per kW)

  • The Iowa Utilities Commission approved the amended filing on May 19, 2025, and the revised RTS rates are expected to take effect June 1, 2025.

Statistics:

  • The total under-collection for 2024 is $1,017,286.32.
  • The interest related to the 2016-2020 wholesale expense true-up was mistakenly included in the 2024 reconciliation, totaling $376,258.30.
  • The RTS rates for various customer classes have been revised, with a decrease in rates for Residential, General Service, Large General Service, Large General Service-Supplementary, High Load Factor, Lighting, Standby, and other customer classes.
  • The "Regional Transmission Service Refund" has been included in the RTS rates for all customer classes, effective June 1, 2025.

Sources:

  • Interstate Power and Light Company, Regional Transmission Service Rider Amended Filing, filed with the Iowa Utilities Commission on May 19, 2025 (Docket Nos. EAC-2025-0150, TF-2025-0019 and RFU-2025-0002)
  • Iowa Public Utilities Commission, Regional Transmission Service, accessed on [date] [link]