With benefits including reduced operations and maintenance (O&M) costs, improved data analysis and enhanced project management, digitalisation is a growing trend in the power industry. Hydropower plants are required to ramp up or down generation depending on the grid frequency, inject reactive power based on the local bus voltage, and provide quick start and stop capabilities in peak times to support the grid. Digitalisation enables hydropower plants to meet these requirements more efficiently and also extends the life of the equipment. It can also reduce the operational complexities and maintenance lags in the plant. While digitalisation became a reality in other parts of the world and sectors some time back, its adoption in India has increased only recently. It is aimed at improving the performance of hydropower plants to reduce costs, increase flexibility and enhance asset management.
A look at the key aspects of digitalisation and its benefits for the hydropower segment in India…
Digital components are available at various stages of hydro plant operations, right from the design and construction of the plant to its operation, management and maintenance. Some of the key aspects of a digitalised hydropower plant are distributed control systems (DCS), digital governors and excitation controllers, numerical relays, and internet-based condition monitoring and predictive maintenance systems.
DCS involves a network of instrumentation comprising sensors, flow switches and transducers, etc. It provides real-time information to operators, allowing complete control of machines and auxiliaries from the control room (often located at a remote location). With a DCS, no manual intervention is required. Numerical relays can record and store a large number of events and disturbance records providing excellent fault diagnosis tools. They are highly configurable as the setting parameters and operational logic can be changed easily. The latest numerical relays, which are based on open protocols, can communicate on the plant control network, improving ease of access.
The internet of things (IoT) brings together industrial machines, advanced analytics and people. It is a network of a multitude of connected devices that monitor, collect, exchange, analyse and deliver valuable new insights. Internet-enabled condition monitoring system (CMS) analyses remotely collected real-time operational data of multiple power stations. It uses machine learning processes to track the health of the plant, detect failures in advance, and improve diagnostics and prognostics of faults. Intelligent predictive maintenance systems are algorithms and models designed to analyse data from the power plant control system. They notify the changes in function and performance using equipment sensors, and identify faults before any serious malfunction occurs. Some of the power plants across the world have also installed drones for the monitoring and maintenance of hydroelectric plants (HEPs).
Digitalisation has numerous benefits in the hydropower segment. Through data and analytics, digitalisation provides better connectivity, effective asset management, predictive maintenance and efficient operations. It improves planning and project design, making them more efficient and less costly. It also reduces operations and maintenance (O&M) costs by enabling predictive maintenance, reduces water usage, improves system reliability and stability, decreases the number of unplanned outages and downtime by rapidly identifying the point of failure, and extends the asset lifetime. Longer lifetimes yield higher revenues and reduce the capex requirements. Further, improved connectivity and monitoring build a strong case for remote operations. Digitalisation also helps in the integration of hydropower operations with other variable renewable energy sources. The operations of hydro and solar power can be closely coordinated with the use of digital systems so that hydro power fills supply and demand gaps in solar generation and hydropower generation can be ramped down when solar power is available to conserve water. Digitalisation also optimises reservoir management and extends the operating range of existing hydro units.
Challenges and the way forward
Despite a multitude of benefits, certain challenges hinder the digitalisation of hydropower plants. Poor network connectivity between power stations and remote centres poses a big challenge as effective digitalisation depends on strong communications connectivity. For commercial confidentiality reasons, asset owners and operators may not be willing to share information about individual power plants and network infrastructure. Cybersecurity is another challenge. Further, there is still a lack of incentives in investments in digital technologies. Despite these challenges, digitalisation is being increasingly implemented in the hydropower segment in India. Going ahead, the projects currently being implemented are likely to drive the implementation of future projects by setting benchmark metrics and sharing best practices in the Indian context.