Operation and maintenance of HESS hydroelectric power plants in 2017
The hydroelectric power plants operated by the company HESS – HPP Boštanj, HPP Arto-Blanca, HPP Krško and HPP Brežice – generated a combined total of 456 GWh of electricity in 2017, of which 115 GWh at the newly built HPP Brežice during the testing of its generating units and the continuation of its trial operation. The year was characterized by rather unfavourable hydrological conditions, which was also reflected in the total electricity generation output.
In the past year, the company reached a major milestone on the project to build hydroelectric power plants on the lower course of the Sava river – the opening of a new member of the chain, HPP Brežice, whose construction began in April 2014. The new HPP started its one-year trial operation on 10 October.
Before HPP Brežice was opened, HPP Boštanj and HPP Arto-Blanca were operated unmanned in normal hydrological conditions via remote control from GEN energija Control Centre and with supervision from a remote control station at HPP Krško, where a plant operator was stationed. A plant operator was also present at HPP Brežice, where a remote control station was set up in September for monitoring and supervising the operation of upriver hydroelectric power plants.
In the past year, all planned maintenance operations were carried out in accordance with our annual maintenance plan, allowing us to run a safe and efficient production of electricity. Periodic inspections and scheduled overhauls of generating units started at HPP Boštanj as early as January, and continued at HPP Arto-Blanca and HPP Krško. In the course of regular operation, all the three hydroelectric power plants underwent all planned preventive, predictive and other regular maintenance activities, as well as regulatory equipment inspections. Periodic inspections and overhauls were accompanied by maintenance work on the shared systems, hydromechanical equipment, power generation components, switching substations, and grid-connected 110kV transformers. Modifications were also carried out on some devices and equipment components at individual power plants so as to increase their operational reliability and to facilitate systems maintenance. Being in trial operation, HPP Brežice underwent several equipment inspections and checks in the last few months of the year. The inspections were conducted in order to verify the correct functioning of the equipment and to eliminate any defects and anomalies before the end of the trial operation period.
Maintenance work was also carried out on water infrastructure facilities: mowing and removal of invasive plants, reconditioning work on the reservoir banks, periodic maintenance of aquatic organism passage facilities (fishways), maintenance of oil separators, etc.
The maintenance activities in the past year were again accompanied by periodic monitoring of technical surveillance of the reservoirs and monitoring of surface water; seismic monitoring and land surveying observations, in addition to technical surveillance, were also carried out at the dam structures of individual hydroelectric power plants.
High-quality maintenance was successfully and efficiently completed by HESS crews in compliance with applicable maintenance directions, technical regulations and the law and in accordance with the results of analyses, tests and checks, as well as the company's business plan for 2017 – in association with HESS's subsidiary Partner d.o.o. and outsourced specialist contractors.
December saw the completion of the final planned maintenance activities and the preparations for carrying out maintenance work in 2018, which is scheduled to start early in January.