Navigating History and Hydropower at HPP Tainionkoski

Situated along the Vuoksi River in the South Karelia region of Finland, the Tainionkoski hydropower plant is a vital piece of Nordic energy infrastructure.
Owned and operated by Fortum, the plant was initially constructed starting in 1947, reaching full commercial operation in 1950. For over seven decades, it has reliably generated renewable energy, currently boasting an average annual production that covers the electrical heating needs of over 15,000 households.

The Technical Foundation

HPP Tainionkoski operates with a unique mixed-turbine configuration designed to maximize the potential of its relatively low 7.8-meter net head.

The powerhouse features four turbines in total: three traditional Kaplan turbines and one Bulb turbine.

These turbines drive a set of four electric generators—three rated at 18 MVA and one larger unit rated at 22 MVA—providing the combined plant capacity of 62 MW.

The Challenge: maintaining a century of heritage

Operating a power plant that dates back to the post-war era presents highly specific maintenance and modernization challenges. Much of the original civil and mechanical engineering was designed before the advent of modern computational tools.

• When critical structural or mechanical components, such as the massive dam floodgates, require replacement, engineering teams often face a lack of original calculations or physical blueprints.
• Modernizing these components frequently involves complex reverse engineering.
• For example, recent renovations at the site required translating roughly 100-year-old, cast-iron gate designs with straight-sided teeth into modern, single-piece machined involute gear profiles to ensure safer and more cost-effective operation.

Conclusion

Tainionkoski stands as a prime example of how historic low-head hydropower installations can continuously adapt to modern standards. Through strategic modernization, careful reverse engineering of heritage components, and robust operations, the plant remains a reliable and crucial cornerstone of clean energy generation in Finland.