LIDAR Technology Leads the Way in Measuring TVA Land
If you own a self-driving car, use an iPhone 12 Pro, or have seen the new Wheel of Fortune puzzle board, you have experienced the benefits of LIDAR technology (Light Detection and Ranging), a remote sensing method that uses light in the form of a pulsed laser to collect spatial information measurements while cameras collect and gather imagery.
In TVA’s Office of Transmission and Power Supply, LIDAR is a critical tool for surveying and mapping for projects such as developing new substation sites or checking the accuracy of transmission line construction. Lasers scan objects such as roads, trees, transmission poles, and wires and return millions of data points that are collected in three-dimensional (3D) point clouds. After post-processing to ensure accurate scale and georeferencing, these 3D point clouds are an extremely accurate model of the project area. They can be used to take precise measurements or to build to-scale digital models.
LIDAR is a tool that can gather a lot of information in a short period of time. It can collect data on thousands of miles of transmission lines more quickly and safely than conventional survey equipment. The collected data, which typically includes a LIDAR point cloud, ambient weather observations, and imagery, is used to develop predictive models that can be leveraged during the engineering design and analysis of the electrical grid system.
According to Adam Green, senior manager of Transmission Line Engineering, “We are in the process of using LIDAR data to build 3D models of all TVA transmission lines 100kV and above. These models will be helpful for responding more quickly to storm damage or helping a TVA customer who wants a new delivery point, as we will already have the data needed to help with design changes. They also help to ensure the reliability of the transmission grid because we can identify any clearance violations which could cause a transmission line to be out of service.”
There are multiple uses for the data LIDAR technology collects.
- It is used in the siting and design of new transmission lines as the data can assist in locating preferred structure positions and help ensure that proper electrical clearances are maintained over the terrain.
- It can be used to design new substation layouts and to estimate earthwork quantities.
- It can help monitor grid health, providing insight into conductor health and detection of anomalies and potential risks.
- Information can be used for vegetation management along the transmission rights-of-way to locate vegetation that might fall into line or otherwise interfere with the flow of electricity.
- It is a tool for erosion management, helping to identify movement patterns around substations and transmission towers.
- LIDAR models help engineers assess external requests to use TVA rights-of-way.
At TVA, LIDAR systems are typically mounted on helicopters, but mobile systems are also mounted on UAVs, trucks, and manned and unmanned boats. Terrestrial LIDAR, an application involving tripod-mounted equipment on the ground, collects similar data but in areas where it would be difficult or impossible to drive a vehicle. For example, terrestrial LIDAR can help determine if a new boiler will fit in the place of an old one or if there is enough room to maneuver a new component through a narrow corridor.
Another benefit of LIDAR is acquisition efficiency. At TVA, survey scientists have developed a single-pass data collection strategy. At the same time, the lasers are pulsing to develop the 3D point cloud, and cameras are being triggered to take forward and rearward oblique photographs, allowing a visual inspection of transmission structures and other hardware. They can be used to zoom into structures to look at hardware such as insulators or cross arms to determine their overall health.
This data can be helpful to many departments within Transmission for a variety of projects. Because this type of imagery is so valuable, TVA surveyors designed the GLIDAS (Geospatial Lidar Information Data Acquisition System) used on its helicopters to ensure higher quality imagery than those systems offered by outside vendors.
As valuable as LIDAR is today, it will become even more critical to TVA’s Grid of Tomorrow. It is a grid-enhancing technology that will optimize the performance of transmission assets, helping, for example, in the determination and development of transmission capacity necessary for the increase in renewable energy integration. Moving forward with LIDAR will enable TVA to see all its physical assets clearly and identify preferred solutions along the road ahead.
Learn more about TVA’s extensive power transmission system.