Slovenia’s only pump-storage hydropower facility is set for a significant technical upgrade after Soske Elektrarne Nova Gorica (SENG), a subsidiary of HSE, finalized an agreement with Japan’s Hitachi Mitsubishi Hydro Corporation (HM Hydro) to refurbish the generator at the Avce plant.
The modernization works are scheduled to begin in 2027 and are expected to take around seven months. The project will be financed entirely from SENG’s own resources and is aimed at securing stable, safe, and dependable operation of the facility over the long term. Financial details of the contract have not been disclosed.
This represents the second major generator refurbishment at HPP Avce. The first overhaul, completed between 2018 and 2019, delivered strong technical results, prompting the operator to continue with a similar approach to extend the plant’s operational lifespan. The upcoming upgrade is designed to ensure full availability of the unit until the next major reconstruction, currently anticipated around the summer of 2036.
Commissioned in 2010, HPP Avce holds a unique position in Slovenia’s energy system. It was among the earliest pump-storage facilities in Europe to feature variable speed technology in pumping mode, allowing for greater operational flexibility and efficiency.
Within the HSE Group, HPP Avce is regarded as a cornerstone of Slovenia’s green energy strategy. By storing surplus electricity during periods of low demand and feeding it back into the network when consumption rises, the plant plays a crucial role in balancing the electricity system. Its ability to support renewable integration also makes it a key asset in the country’s broader transition toward a low-carbon energy future.