Otter Tail Power Company, a wholly owned subsidiary of Otter Tail Corporation (NASDAQ:OTTR), today announced the South Dakota Public Utilities Commission approval of the settlement agreement reached between Otter Tail Power and commission staff, concluding the rate proceeding.

Investor highlights:

Net revenue increase of $3.3 million
Achieved 58% of original request; 75% after considering adjustments for rider treatment
Blackbox settlement regarding return on equity and capital structure
Return on rate base of 7.09%
Moratorium on increases to base rates until December 1, 2029, with certain exceptions

"Today's outcome reflects a constructive regulatory process, and is expected to support safe, reliable and economical electric service for our South Dakota customers," said Otter Tail Power President Tim Rogelstad. "We appreciate the collaboration with the South Dakota Commission and staff throughout the proceeding."

Final rates are anticipated to be implemented on April 1, 2026. Even with the increase, Otter Tail Power is expected to continue having some of the lowest electric rates in the region and country.

Forward Looking Statements

This release includes forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements can be identified by words such as "anticipate," "expect," "will" and other similar words and expressions. Such statements are based on the current beliefs and expectations of management. Forward-looking statements made herein, which may include statements regarding the approved net revenue increase, the authorized return on rate base, our ongoing capital investment plans, the anticipated financial and operational impact of the South Dakota rate review and the implementation of final rates as well as other assumptions and statements, involve known and unknown risks and uncertainties that may cause our actual plans or results to differ from our assumptions or expectations.

Our risks are more fully described in our filings with the Securities and Exchange Commission, including our most recently filed Annual Report on Form 10-K, as updated in subsequently filed Quarterly Reports on Form 10-Q, as applicable. Forward-looking statements speak only as of the date they are made, and we expressly disclaim any obligation to update any forward-looking information.

About the Corporation

Otter Tail Corporation, a member of the S&P SmallCap 600 Index, has interests in diversified operations that include an electric utility and manufacturing businesses. Otter Tail Corporation stock trades on the Nasdaq Global Select Market under the symbol OTTR. The latest investor and corporate information is available at www.ottertail.com. Corporate offices are in Fergus Falls, Minnesota and Fargo, North Dakota.

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Investor contact: Beth Eiken, Manager of Investor Relations, (701) 451-3571

Media Contact: Stephanie Hoff, Director of Corporate Communications, (218) 739-8535

Otter Tail Power Company Completes Rate Review in South Dakota