Last Updated 1 hour ago by Kenya Engineer
As electricity demand grows and power grids accommodate more wind and solar generation, hydropower plants are being called upon to deliver dependable electricity while meeting increasingly demanding operational requirements. For plant operators, this puts a premium on equipment reliability, effective control systems and the ability to maintain ageing assets without necessarily rebuilding entire facilities.
A modernisation programme at Norway’s Vikfalli hydropower complex illustrates this approach. In 2026, ABB was selected by Statkraft to upgrade the control, protection, excitation and electrical systems at three power stations with a combined installed capacity of 184 MW.
The project reflects an important consideration for electricity utilities: strengthening existing generating assets can complement investment in new capacity. However, the benefits depend on the condition of the equipment, the scope of the work and how effectively new systems are integrated with the machinery already in place.
Upgrading the systems behind generation
The Vikfalli complex comprises the Målset, Refsdal and Hove power stations, with installed capacities of 24 MW, 92 MW and 68 MW respectively. According to ABB, the five generating units produce approximately 830 GWh of electricity annually.
The upgrade covers a range of equipment, including a distributed control system, electrical systems, excitation equipment, protection devices, vibration monitoring and cybersecurity measures. The new control platform will also be integrated with existing turbine systems supplied by other manufacturers.
These components perform different but closely related functions. Turbines convert the energy of moving water into mechanical power, while generators convert that power into electricity. Control and electrical systems regulate the operation of the generating units, monitor their condition and protect them when faults or abnormal operating conditions arise.
A distributed control system brings plant monitoring and operational functions into a coordinated environment. It gives operators information on equipment performance and enables them to manage plant processes through an integrated platform.
Protection systems serve a different purpose. They detect faults such as short circuits and abnormal electrical conditions, initiating the appropriate response to isolate affected equipment and limit damage. Their settings must be coordinated with the generator, transformer, switchgear and wider power system.
Excitation equipment is equally important. It regulates the magnetic field in a synchronous generator, helping control terminal voltage and the generator’s contribution to reactive-power management. These functions support the operation of the generating unit within the electrical limits of the plant and the requirements of the grid.
Updating these systems can improve monitoring, control and maintainability. It does not automatically increase the amount of electricity a turbine can produce or improve its hydraulic efficiency; those outcomes depend on the condition and performance of the generating machinery itself.
Why excitation and protection
A hydropower plant must operate within the voltage, frequency and stability requirements of the electricity network to which it is connected. Changes in grid conditions can place different demands on generators, particularly when the balance between generation and consumption shifts.
Excitation systems help generators regulate voltage and manage reactive power within their operating limits. Protection systems, meanwhile, must identify faults quickly and coordinate with other protective devices to prevent damage from spreading through the installation.
These capabilities remain important as the generation mix changes. Wind and solar power can vary with weather conditions, increasing the need for effective system balancing and appropriate voltage support. Hydropower units can contribute to these functions, depending on their design, operating condition, available water and the requirements of the grid.
ABB’s Vikfalli programme includes UNITROL 8000 excitation systems for all five generating units, alongside modernised control and protection infrastructure. Vibration monitoring is also part of the scope, allowing operators to track indicators of mechanical behaviour and investigate developing problems.
Such monitoring can help maintenance teams identify changes that warrant inspection before they develop into serious failures. Its effectiveness depends on the quality of the measurements, appropriate alarm thresholds and a maintenance regime that responds to the information collected.
The project also includes cybersecurity measures. As plant control systems become more digitally connected, operators must manage access rights, network connections, software vulnerabilities and the risks associated with unauthorised access. These safeguards need to be designed around the requirements of operational technology, where an inappropriate intervention can affect physical equipment and electricity production.
Extending asset life without rebuilding the plant
Modernising selected systems can be an alternative to replacing an entire hydropower installation, particularly where the main civil structures, turbines and generators remain serviceable.
A complete refurbishment may involve major mechanical works, generator replacement, civil engineering and lengthy outages. A targeted programme can instead concentrate on equipment that is ageing, difficult to maintain or no longer adequately supported by its manufacturer.
The right approach must be established through condition assessments and engineering studies. If a turbine has suffered substantial wear or a generator has deteriorated, replacing the control system alone will not resolve the underlying problem. Conversely, where the main machinery remains in good condition, modernising controls, protection and excitation equipment may address important operational risks without the cost of a complete rebuild.
Integration presents its own challenges. New control equipment must communicate reliably with existing turbine governors and other plant systems. Protection settings need to be coordinated, and the combined installation must be tested to confirm that it responds correctly under normal operating conditions and during faults.
Outage planning is another important consideration. Each generating unit may need to be taken out of service for installation and testing, reducing available capacity during the work. Scheduling must balance these requirements against electricity demand, maintenance needs and the availability of other generating units.
According to ABB, site work is scheduled to begin at Målset in 2028, followed by Refsdal and Hove in 2029. The programme is therefore a planned upgrade, and its actual effects on reliability and performance will become clearer after installation, commissioning and operational assessment.
What hydropower operators can learn
For Kenya and other countries operating established hydropower stations, the relevant question is which investments will deliver the greatest improvement in reliability and long-term asset performance.
That decision should begin with evidence. Equipment-condition assessments, failure histories, maintenance records, outage data and performance measurements can help identify whether recurring problems originate in turbines, generators, electrical protection, controls or auxiliary systems.
The investment case should then consider the cost of equipment replacement against the consequences of continued failures, unplanned outages and difficulties obtaining spare parts. Operators should also assess cybersecurity, staff training, technical support and the availability of replacement components over the expected life of the new systems.
Where efficiency gains are anticipated, performance should be measured against an established baseline. Where the objective is improved reliability, useful indicators include forced-outage rates, maintenance requirements, equipment availability and the time needed to restore a unit to service.
Modernisation is not a substitute for maintaining the turbine, generator or dam itself. It is part of a wider asset-management strategy that must address the condition of the entire installation.
The Vikfalli programme demonstrates how upgrades to control, excitation and protection systems can be coordinated across an existing hydropower complex. For operators facing ageing equipment and growing demands on their generating assets, the priority is to identify where targeted investment can keep plants dependable, maintainable and fit for the requirements of the electricity system.
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