Digitalisation of power plants entails the use of sensors in power plant equipment as well as the adoption of digital solutions such as blade vibration monitoring system (BVMS), condensate throttling, 3D printing and steam leakage detection system to optimise plant operations and enhance operational efficiencies. In recent years, power plant digitalisation has gained momentum for managing thermal power plant operations, with growing renewable energy integration and the tightening of emission norms. The digitalisation of power plants offers a host of benefits such as fuel optimisation, asset management and reduced emission levels. Owing to the benefits of digitalisation in power plants, utilities in India and the world over are increasingly investing in digital solutions. As per the Bloomberg New Energy Finance (BNEF) 2017 report, investments in digital energy are growing at 20 per cent every year, reaching $55 billion globally last year. With digitalisation, power companies not only monitor but also intelligently and actively predict, manage and even remotely control decentralised and complex energy networks. It also helps in making more informed decisions and improving customer relationships.
Digital solutions for power plants
Broadly, digitalisation entails the use of sensors, actuators, digital controllers and supervisory computers in power plant equipment. The data obtained from these is analysed to predict plant performance, evaluate different scenarios, understand trade-offs and enhance efficiency. Besides this, there is growing traction in the use of internet of things (IoT)-based sensors in power plants. This allows modification of plant operations in near real time and better monitoring.
Apart from this, various digital solutions for power plants have been developed to achieve the desired outcomes. One of these is BVMS, which prevents last-stage blade failure in turbines, which occurs as a result of electrical corrosion, corrosion fatigue, stress corrosion, water corrosion and equipment fatigue caused by material quality issues and load variation. Another digital solution useful in the power generation segment is 3D printing, which helps in maintaining spares readiness with additive manufacturing and minimising the lead time for spare part manufacturing. It is also cost effective. Condensate throttling is a widely used digital solution to maintain plant performance under a quick response load change scenario. In September 2017, a condensate throttling-based primary frequency control solution was commissioned at NTPC’s Dadri thermal power plant (Stage II, Unit 6). Apart from this, an acoustic steam leakage detection system can help track steam leakages in boilers with the use of sensors on a sonic tube. In case the sound of the steam leak exceeds a preset limit, an alarm is set off and the registered contacts alerted. Another emerging solution is operating the plant remotely by creating its digital twin. A digital twin is an organised collection of physics-based methods and advanced analytics is used to model the present state of every asset of the plant. The digital twin uses algorithms and models of artificial intelligence and machine learning to predict the future performance of the plant.
Usefulness of plant digitalisation
In a digital plant, with the use of feedback control loops, plant processes and performance can be monitored and appropriate control actions taken to maintain optimum conditions despite system disturbances such as changes in coal quality or load demand. With the use of analytics, information and operational technology solutions, meaningful insights can be derived from operational data, and corrective measures taken to maintain plant performance, reduce unplanned outages and downtime, and extend the operational life of assets. Besides, through digitalisation, plant operations can be remotely monitored and modified based on performance parameters. One of the key benefits of digitalisation is in managing the operations of conventional power plants in light of the large-scale penetration of renewable energy into the grid. Conventional power plants have to operate at a lower/variable plant load factor in order to accommodate renewable energy. Digitalisation helps in maintaining plant performance during part-load and cyclic operations. Further, it helps in optimising asset management practices at the plant. The data collected from the sensors installed in the plant is transformed into actionable intelligence by combining robust analytics with domain expertise, thereby moving from reactive and preventive maintenance to predictive maintenance. Digitalisation also helps in keeping a check on the cost of complying with environmental regulations. Asset optimisation strategies and digital solutions help plants in lowering their emission levels and minimising fuel usage.
In order to realise the full benefits of digitalisation in power plant operations, it is essential for utilities to collect and analyse the data generated by various digital power plant equipment. This will help predict future scenarios, enhance operational efficiency and facilitate asset maintenance. Developers need to select digital solutions keeping in view the age of the plant, the desired outcomes and plant location to obtain the best results. The downside though is that digitalisation makes utilities more vulnerable to cybersecurity attacks and as such, utilities need to proactively manage this risk and adopt best practices to keep their systems secure and up to date.