Wildfires present a major challenge for utilities. Devastating wildfires often can be caused by their own infrastructure, so utilities have a critical responsibility to manage risk presented by their network. Utilities also have an obligation to ensure the safety of affected communities during a wildfire event.
Some utilities are taking advantage of new technologies to mitigate wildfire risk. For example, digital twin technology can create a highly accurate 3-D model of an entire network, which — when combined with other data sets — can be used to accurately model risk relating to the network and its surroundings.
One digital twin technology being adopted by utilities in the wildfire-prone parts of Australia is Neara. This physics-enabled platform builds 3-D interactive models of critical infrastructure networks and assets, providing the ability to run real-world scenarios, assess current and future risks, and prioritize network investment, maintenance and disaster response. Here are some ways digital twin technology is helping utilities to manage wildfire risk.
Better Vegetation Management
Vegetation management typically is the highest-cost item for utilities, and rightly so, because vegetation requires continual cyclic treatment and can present one of the greatest wildfire risks.
Neara ingests and classifies light detection and ranging (LiDAR) data to produce highly accurate virtual representations of network assets and their surroundings. However, vegetation risk extends beyond simple proximity to wires. A common fire ignition source is direct contact of vegetation and wires. This can happen by growth of trees into the lines (grow-in risk), nearby trees falling onto power lines (fall-in risk) or lines blowing into trees (blow-in risk). Additionally, there is the risk that occurs when an asset fails and drops the conductor, which then can make contact with vegetation on the ground.
With digital twin technology, utilities can quickly and easily detect vegetation encroachment within conventional clearance zones and highlight those violations across the network. Users have the power to redefine and iterate on the dimensions of these zones, and compare the resulting violation count, risk and cost. At-risk locations can be detected and highlighted across the network, so engineers and contractors can identify and prioritize their at-risk assets and proactively take action.
Similarly, digital twin technology can model the heightened probability of vegetation falling into the network using modeled vegetation fall-in arcs and terrain models that can point to areas more conducive to wildfires getting out of control.
Simulating Weather Impacts
Digital twin technology enables utilities to simulate the possibility of contact or encroachment under any given weather condition or load on a per-span basis.
Calculating sag and sway is an important part of assessing fire risk. In conditions where power lines are impacted by high temperatures and increased load, Neara data shows sag can vary by as much as 30%. Sway (also known as blow-out) is the space in which wires move and is similarly impacted by weather conditions and increased load.
To assess the true risk of line-vegetation contact, it is crucial to account for scenarios where power lines are sagging or swaying at maximum operating temperature.
While the amount of sag and sway experienced by power lines depends on numerous factors, including the length of the span and the configuration and tension of the conductors, Neara’s digital twin technology can calculate sag and sway based on these attributes as well as the climate and weather events to which they are exposed.
Mechanical activities also can spark a fire, such as conductor clashing or galloping, which can be caused by high winds combined with extreme temperatures. Under these conditions, the lines can slap into each other or arc, causing electricity to jump between two lines, which can trigger sparks. When sparks fly off power lines that are traversing dry grass and leaf litter, a wildfire can spread quickly. Conductor clashing and galloping also can damage or weaken any attached assets, especially when line tension changes so drastically it causes a pole to fall, leaving live wire in close contact with the ground.
The Neara platform can simulate all these conditions and highlight areas where conductor clashing or pole failure might occur and lead to wildfire, so utilities can easily identify potential problems in the network model before they occur.
Another key part of fire mitigation is ongoing asset maintenance, because fire is often caused by failure of aged and damaged infrastructure. By running simulated weather events on a digital twin like Neara, utilities can assess which network assets are likely to fail first. This information can inform important grid hardening initiatives.
The digital twin technology can incorporate climate data within a model, so utilities can pinpoint at-risk assets within at-risk areas, such as areas prone to hot and dry conditions, so repairs and replacements can be prioritized appropriately.
In the event of a wildfire, utilities follow a response plan that usually involves planned power outages. Shutting off power to affected areas removes the risk presented by fallen poles and live wires. Sometimes a high wind event without fire is reason enough to shut off power, because of the fire risk the damaged or fallen equipment poses.
Neara can help this process by providing utilities with a highly accurate representation of their network, including geospatial data, allowing them to map the likely path of the fire based on weather conditions. This enables them to accurately predict which network assets will be affected next, so they can make smarter decisions on planned outages and minimize negative impacts on customers.
Firefighters do not rush to protect a power pole from burning; their efforts are rightly focused on saving lives. This means damage to a utility’s infrastructure is inevitable during a wildfire and the cost of rebuilding is expensive. However, fire damage does present an opportunity to modernize and replace aging assets. For example, replacing wood poles with more durable metal poles.
Neara’s engineering-grade software enables utilities to easily design new portions of their network. Not only that, but it can help utilities to understand the condition of the infrastructure before a fire and run a simulation on a new design to see if the fire risk can be removed or reduced with some simple design decisions before they commit to physical construction.
Physics-based calculations applied to the model can help to build more resilient and less risky infrastructure. This might mean moving poles or changing line tension, or even identifying a combination of assets that caused a failure in the past and remodeling them.
The digital twin technology can be used to run a search for asset combinations at network scale to see if identified issues exist elsewhere, so they can be addressed proactively.
A Case Study
Essential Energy builds, operates and maintains one of Australia's largest electricity distribution networks — delivering electricity to more than 880,000 homes and businesses across 95% of New South Wales and southern parts of Queensland through 125,000 miles (201,168 km) of network.
As part of their commitment to safety, Essential Energy used Neara’s platform to mitigate risk, including the risk of wildfire. The project involved using LiDAR to build a 3-D network model of poles and conductors and their surrounding vegetation.
When wildfires ravaged Australia in the summer of 2019-2020, Essential Energy overlaid wildfire data on its network model in Neara’s platform to identify and assess damaged and at-risk assets. This information assisted the utility to make repairs and restore power to communities.As a result of the successful work on wildfire mitigation and response, the utility expanded its scope with the platform to undertake other grid-hardening activities, such as encroachment and pole loading analysis as well as using digital twin modeling to assess the fall-in risk for trees across its network.
Utilities need to take wildfire risk seriously, while also balancing prevention efforts with cost impacts to consumers. This means intensive fire-prevention projects, like undergrounding an entire network, is simply not realistic. Therefore, utilities must be smart about how wildfire mitigation work is done to optimize capital expenditures.
With wildfires becoming all too frequent across many parts of the globe, the use of a highly accurate, interactive 3-D digital twin can remove a lot of the guesswork involved in planning for and responding to these devastating events, ensuring time and resources are well spent. And, ultimately, support a utility’s goals for safe and reliable power.
Robert Brook is SVP and GM Americas at Nearaand has spent more than 30 years in the energy and information technology industries and is a recognized expert in the development and implementation of technology for infrastructure and asset management as well as risk mitigation. He previously has filled key industry positions, including president of Hecatic Labs, senior director of business technology at Pacific Gas and Electric Co., and global utility industry manager at Esri.
Neara is hosting a free live webinar on wildfire mitigation using its platform on Tuesday, June 28, 2022 at 2:00 pm EDT. Register here.