Otter Tail Corporation is a holding company that operates an electric utility, manufacturing businesses, and plastic pipe businesses. The company provides electric generation, transmission, distribution and sale services in western Minnesota, eastern North Dakota and northeastern South Dakota. Its manufacturing segment produces metal fabricated parts and thermoformed plastic products, while its plastics segment manufactures PVC pipe for municipal water infrastructure. These operations serve a diverse set of customers across the United States and Canada.

Revenue is generated primarily from the sale of electricity to residential, commercial and industrial customers, as well as from transmission services and wholesale market transactions. The manufacturing segment earns income from the production of metal components for original equipment makers and from thermoformed plastic products sold to various industries. The plastics segment derives revenue from the sale of PVC pipe to distributors who serve municipalities, contractors and other end users involved in water infrastructure projects.

The company operates through the following segments: Electric, Manufacturing, and Plastics.

• Electric: This segment encompasses the generation, purchase, transmission, distribution and sale of electric energy, serving approximately 134,000 customers in a predominantly rural and agricultural service area covering western Minnesota, eastern North Dakota and northeastern South Dakota.

• Manufacturing: This segment includes metal fabrication services that produce custom machine parts and components, as well as thermoformed plastic products for horticulture, medical and industrial markets, with facilities in Georgia, Illinois and Minnesota.

• Plastics: This segment manufactures polyvinyl chloride (PVC) pipe used mainly in municipal water, wastewater and storm drainage systems, operating plants in North Dakota and Arizona and selling primarily in the western half of the United States and Canada.

Otter Tail Corporation holds a distinct position as a regulated electric utility with a low cost rate advantage, while its manufacturing and plastics businesses compete in fragmented markets where breadth of capabilities and customer relationships provide differentiation. In the electric sector, the company faces competition from municipal utilities, rural electric cooperatives and occasional distributed generation, but its rates remain substantially below regional and national averages. The manufacturing segment contends with numerous small fabricators and larger diversified firms, winning business through its extensive tooling, automation and long term OEM relationships. The plastics segment operates among a limited number of domestic PVC pipe producers, competing on product availability, service responsiveness and adherence to quality standards.

The electric segment serves residential, commercial and industrial customers across more than 400 communities, with two unspecified customers accounting for 16% of segment revenues in 2025. The manufacturing segment sells to a range of original equipment makers, including Caterpillar Inc., CNH Industrial N. V., Cummins Inc., Deere & Company, Honda Motor Co., Kawasaki Heavy Industries, Polaris Inc. and The Toro Company. The plastics segment distributes its PVC pipe through a network of over 200 distributors, with two national distributors contributing a significant share of sales, while end users consist of municipalities, contractors and other governmental entities involved in water infrastructure.