Kemijoki Oy is one of the most significant producers of hydro and regulating power in Finland since it produces about one-third of Finland’s total hydropower. The company owns 20 power plants and nearly 40 hydropower units, most of which are located in Lapland along the Kemijoki and Kitinen rivers.

The Vajukoski hydropower plant, which was commissioned in the early 1980s, had been in use for 35 years. It was now time to update the automation system of the plant to meet today’s standards and VEO was selected as the main supplier of the renovation project that would take place.

”Vajukoski is our first power plant in a long time, whose new automation solutions are supplied by an external partner. In tendering, VEO’s offer stood out thanks to their cost-efficiency and security of supply. In addition, VEO has many long-term hydropower experts who had previously gained some of their knowhow as employees of our company,” says Sami Soudunsaari, senior specialist at Kemijoki Oy.

The Vajukoski hydropower plant, on the Kitinen river, was partly renovated during the summer of 2019.

”The delivery included the unit and station automation based on a Siemens S7-1500 TIAPortal system, a VEO G800 generator excitation system and a Siemens Siprotec 5 generator protection system. The automation systems were also integrated into the power plant’s existing systems with distributed-IO, in order to achieve the most cost-efficient solution,” explains Juha Mäki, VEO’s Hydropower Sales Manager, and Vajukoski’s renovation Project Manager.

Implementation of information accessibility and usability

Power plant technology has developed by leaps and bounds over the last 40 years. As a result, the renovation of the automation systems at Vajukoski was necessary to be able to bring the plant’s operations into line with today’s technological standards. For both VEO and Kemijoki, the Vajukoski power plant renovation was to be a pilot project in a number of ways; it was VEO’s first project where their new automation platform was commissioned and it was Kemijoki’s first power plant to comprehensively use modern technology, including IEC-compliant data transfer and access control system connections.

In the Vajukoski project, special attention was paid to the usability of the automation system. When more relevant data becomes available from the power plant, the plant’s rehabilitation will improve, faults will reduce, and problems can be quickly detected.

”The users of the power plant were able to comment on the plans in advance and thereby influence the outcome. We worked very closely with VEO during the design phase. It is easy to be satisfied with the result when you have had an impact on it,” says Soudunsaari. 

Tight schedule throughout the project

As with most renovation projects, the Vajukoski project was made on a very tight schedule. The cooperation agreements were signed before Christmas 2018, and the work began immediately after the turn of the year. In less than eight months, the entire renovation was completed.

”Vajukoski was a very successful project. The schedule itself is often the Achilles heel of renovations, but at Vajukoski we were able to keep to the schedule, thanks to the high expertise of our employees and their mutual understanding with the customer,” says Juha Mäki.

Keeping to the schedule plays a critical role in power plant projects, not only because the shutdown is always a cost for the power plant owner, but also because of the availability of energy.

”All the power plants along the Kitinen river are single turbine plants, so the entire power plant must be shut down during the renovation. It is a waste of energy to run water past the turbine,” Soudunsaari explains.

”We are pleased with the outcome and will continue to work with VEO on similar projects in the future.”

”Commitment to the schedule was one of the reasons why VEO was selected as a supplier. The schedule was tight because we wanted the shortest possible lead time for the shutdown – and that is what we got. VEO performed well during the downtime. For Kemijoki, it was important that everyone kept to everything that was agreed on, and this was well implemented in the Vajukoski project, both in terms of schedule and cost. Overall, we are pleased with the outcome and will continue to work with VEO on similar projects in the future. Our next cooperation project will be the Porttipahta power plant, which will be renovated in the same style as Vajukoski.”

The automation and excitation of Kemijoki Oy’s Vajukoski hydropower plant were made on an extremely tight schedule.