Two European hydropower plant operators have turned to Canada’s Thordon Bearings to replace bearings on their Francis turbines, citing issues with oil leakage from their original metal bearings.

In separate contracts facilitated by Thordon's authorized distributor for the region, Croatia-based Skoring d.o.o., wicket gate bearings were supplied to the 36.8MW Hrvatska Elektroprivreda-operated plant in Rijeka, Croatia, in July. Subsequently, in August, new turbine guide bearings were retrofitted to turbines at the 1500kW Elektro Ljubljana-operated HPP Sava Brod plant in Slovenia.

For Hrvatska Elektroprivreda (HEP Group), the decision to replace the original greased bronze wicket gate bearings on the Rijeka plant’s 18.4MW Turbine B was an easy one to make, given the longstanding relationship with Skoring, the authorized distributor for Thordon Bearings in the region.

Skoring’s Technical Manager, Goran Orlic, highlighted the strong ties: “We have a great relationship with Hrvatska Elektroprivreda, an important customer for us. We have provided the utility supplier with numerous bearings over the years, with our first installation taking place at the Ozalj hydropower plant in 2002. Since then, we have retrofitted turbines at HEP plants in Fuzine, Zagreb, Lepenica, and more.”

In July 2021, ThorPlas-Blue wicket gate bearings were retrofitted to Turbine A of the Rijeka plant, followed by Turbine B in May 2023. The Thordon scope of supply for each turbine included twenty self-lubricating ThorPlas-Blue bearings and twenty 135mm (5.31in) Thorseal polymer lip seals.

The smaller 100-year-old Elektro Ljubljana plant near Ljubljana, Slovenia, underwent retrofitting with Thordon SXL water-lubricated turbine guide bearings in August. The SXL bearing material was supplied by Skoring to local turbine refurbishment company Hydro-hit for final machining to fit shaft diameters of 305mm (12in).

Axel Swanson, Thordon Bearings’ Business Development Manager – Hydro & Industrial, emphasized the longstanding collaboration with these operators: “Skoring has a long history supplying Thordon seals and bearings to these operators. Both HEP Group and Elektro Ljubljana have been very satisfied with the performance and environmental efficiency of our products and they often upgrade their turbines with Thordon’s bearing and seal solutions at each refurbishment to achieve the ultimate wear life and eliminate the risk of pollution.”

Swanson highlighted Thordon's environmental advantages, stating: “Thordon solutions do not pollute, are simple to maintain, and offer excellent wear performance and abrasion resistance compared to other oil- or water-lubricated bearing solutions in the marketplace. Of course, shorter lead times and competitive pricing also play a part!”

Malcolm Barratt, Thordon Bearings’ Regional Manager – Southern Europe & Gulf Med, emphasized the potential benefits of upgrades and refurbishments in the hydropower industry: “Globally, more than half of all active hydropower plants were originally commissioned over half a century ago but upgrades, refurbishments, and the use of more reliable turbine components, such as Thordon’s pioneering elastomer technology, can be hugely beneficial in reducing downtime and keeping the lights on.”

Commissioned in 1968, HPP Rijeka is a high-pressure derivation plant that annually produces about 84.45GWh of electricity from the Rječina watercourse. The historic HPP Sava Brod, operational since 1928, draws water from the Sava River in Brod, a village north of Ljubljana, Slovenia.

Above: Thordon SXL bearings being bonded into the turbine guide bearing housings; top: Thordon’s ThorPlas-Blue wicket gate bearings being installed