Mark Ewen, Vice President-Utilities & Geospatial BU, Cyient; and Sunil Kotagiri, Lead Consultant-Utilities & Geospatial BU, Cyient; discuss how supply reliability can be improved with intelligent vegetation management.
Regardless of where in the world a utility operates, or under what variation of regulatory regime, three priorities resonate across them all: ensuring that the energy supply is reliable, supplying it efficiently and safely. Per a 2014 report by the Forum of Regulators, India would require an investment of about $238 billion to achieve 24x7, reliable, secure, and quality power supply to all the consumers by 2018-19. To maintain these priorities, the Government of India (GoI) has created a roadmap for strengthening transmission and distribution lines. The roadmap also envisages rolling out of smart meters across the nation, implementing wide area monitoring systems, developing micro-grids, thrust to renewable generation, and establishing secure communication infrastructure for greater visibility and control of networks.
However, the addition of new lines and renewable sources will increase the complexity of transmission networks and ultimately, increase operations and maintenance (O&M) costs. Renewable injections affect the variability in residual electricity demand thereby risking grid stability and supply reliability. Strengthening the transmission and distribution (T&D) infrastructure entails protecting the infrastructure from vegetation, weather and peak loads.
Considering these issues, a joint initiative of the World Energy Council-India (WEC-India) and the Power Grid Corporation of India Limited (PowerGrid) identified a few strategic areas to focus on. 'Condition Based Monitoring' and 'Preventive Maintenance' are two among them. While preventive maintenance is applicable across a utility, vegetation management is one of the key areas for improving supply reliability, safety and operational efficiencies.
Why vegetation management?
Vegetation remains one of the leading causes of outages globally on both T&D networks. The 2003 north-east blackout, one of the largest in North American history, was triggered by unchecked tree growth and poor vegetation management. One estimate attributes two-thirds of electrical outage minutes to weather-related incidents, while a third of these are attributed to growing vegetation coming into contact with utility lines, poles and transformers.
Though ensuring network assets are free from encroachments from surrounding vegetation is a recurring and expensive activity, it is an essential obligation for utilities to avoid unscheduled outages, forest fires, loss of revenue and to comply with stringent reliability parameters and safety regulations. Vegetation management processes prove to be inefficient if they are planned and executed with traditional tools and techniques. In the context of grid modernisation, it is prudent for utilities to deploy advanced technologies such as unmanned aerial vehicles (UAVs), machine learning techniques and 3D tools to develop an efficient vegetation management system.
Leveraging latest technologies
From our perspective, the vegetation management value chain has four key aspects ù asset data sourcing, data processing and analysis, visualising for effective decision making, and integration with enterprise systems. The application of advanced tools and techniques in each of these phases improves the efficiency of the utility multi-fold.
Asset data sourcing: In this phase, data from the transmission infrastructure, trees and other obstacles along the right-of-way (RoW) is sourced in multiple ways with field survey and airborne survey being the most commonly used. Lasers (Light Detection and Ranging - LiDAR) or optical sensors are used during airborne surveys to identify grid infrastructure and the vegetation points of interest. This approach is expensive, though the costs can be recovered over time by minimising outages and avoiding regulators' penalties. Unmanned aerial vehicles (UAVs or drones) are now being deployed as an alternative and cost effective method of data acquisition. They can be equipped with LiDAR sensors to gather 3D data of the transmission and distribution corridors.
Data processing & analysing: After the data from T&D networks is acquired, it is processed and classified into various feature types, such as transmission lines, towers, trees, etc., to pinpoint current and predict future vegetation encroachments. Existing prediction systems are built to understand tree growth based on type of species, weather and geography. These systems can be fine-tuned by using machine learning algorithms that use historical growth patterns to predict the future growth areas more accurately.
Visualising for effective decision-making: Visualising the tree growth is the next important step to plan, schedule and take necessary action. With geographical information systems (GIS) becoming a central component in many enterprise-wide IT solutions, the presentation of reporting and visualising tree encroachments under different thresholds is enhanced. A spatially-enabled solution with 3D views will provide accurate visualisation of the T&D corridors, facilitating timely intervention. Such a solution allows dashboarding views for senior management to comprehend the situation and take effective decisions.
Integration with enterprise systems: A typical vegetation management solution will produce reports depicting vegetation encroachments. The performance of such a solution can be enhanced by integrating it with the existing IT systems including GIS, outage management system (OMS), and mobile workforce management system (MWM). This makes the entire system intelligent enough to understand connected infrastructure, predict outage affected areas as a result of vegetation encroachments, and enables workforce scheduling to manage the tree trimming activities. Such solutions help improve response times and consequently improve supply reliability.
Cloud-based solution as a service
Cloud-based solutions have seen huge uptake over the past few years. Though reticent at first, the utilities industry started adopting cloud-based solutions to reduce the response time between initiation and deployment.
Considering the recurring nature of the task, utilities are seeing vegetation management solutions 'as-a-service', and as a compelling option to off-load the complete responsibility to vendors who deliver end-to-end vegetation management as a service - starting from data sourcing to scheduling vegetation maintenance jobs.
Though not a universal and singular solution to address supply reliability, vegetation management is an effective way to mitigate local outages from a distribution standpoint and avoid cascading outages and blackouts from a transmission perspective. India aspires to achieve 24x7, reliable, secure, and quality power supply to all the consumers by 2018-19. However, the Draft National Electricity Plan (prepared in accordance with the National Electricity Policy) unveiled by the Ministry of Power in December 2016, does not highlight tree-powerline conflicts nor educates the stakeholders on the need for vegetation management for improving supply reliability. Given the essential nature of power outages and increasing consumer expectations, it is necessary that utility companies and regulators come together to frame appropriate policies and regulations to enhance the focus on vegetation management.
Benefits of Vegetation Management
- Minimise outages, improve supply reliability;
- Reduce damage to assets;
- Improve financial health of utility;
- Avoid forest fires;
- Meet safety/regulatory norms;
- Mobilize and automate workflows;
- Capture information at point of conception:
Accelerated information flow within the enterprise,
Increases data integrity/quality;
- Improve productivity/efficiency:
Data distributed and collected electronically,
Better communication with other departments;
- Better support analysis and reporting;
- Allow timely, cost-effective decisions.