Vegetation management is the act of clearing and maintaining the vegetation around power lines, transmission lines, and other utility assets. That may sound simple, but there's a lot more to vegetation management than trimming trees. And we'll learn about all of that in today’s article.
Vegetation management is an important aspect of asset management for Utilities. Many power outages in the U.S. are caused by vegetation interfering with power or transmission lines.
For example, in August 2003, around fifty million people in the US and Canada experienced a blackout, and the root cause for the power cut was some trees growing into the power lines. It is estimated that on ground level, the culprit behind one-third of power outages is vegetation interference. Additionally, improper vegetation management has been known to be the cause of wildfires.
At 2019’s DistribuTech conference, Elizaveta Malashenko, deputy executive director of CPUC, revealed that Utility ignitions were responsible for 10 percent of all wildfires in California. And the number one reason for ignition was vegetation interfering with transmission lines.
So, to avoid outages and wildfires, the need for vegetation management is pretty much self-explanatory.
Let’s look at some best practices and considerations.
As stated earlier, vegetation management is clearing and maintaining any vegetation that can come in contact with the power & transmission line, and electric facility.
It is also known as Vegetation Management Program (VM Program).
Now, under a vegetation management program, there are several ways in which vegetation can be controlled:
The nature of the activity to counter vegetation risk depends on various factors like the type of vegetation, foreseen growth, cost-effectivity, governing laws, and the number of solutions available.
For instance, if a tree is infected and would be prone to fall during a storm or hurricane, it would be wise to either remove it or cut it short enough that it doesn't fall on lines.
This is where data and risk analysis come into play. More on data and risk analysis later.
Now, let’s briefly examine the methods used in a vegetation management program:
If the vegetation or tree work meets the standards of ANSI Z-133, which is the American National Standard for Arboricultural Operations, then you prune the vegetation or tree.
Yes, there are standards for trimming trees and vegetation, and for a reason.
Before removing any tree or branch, the contractor or vegetation manager takes into account the growth rate, distance from lines, wind force, or snow it can endure.
This is because tree cutting is often an unpopular activity. So, it’s made sure that only the required amount of vegetation is pruned.
One more reason why contractors and vegetation managers are so selective is this. Even though trimming trees and vegetation generally results in thicker and more aggressive growth, mindful trimming can make the vegetation grow away from lines and right of way, which is a win-win situation.
In some cases, pruning of vegetation is not enough, or it is not a long-lasting solution. Therefore, vegetation managers sometimes opt to remove entire trees and brushes.
The selection of trees and bushes for removal is largely impacted by the geography of an area. For instance, certain bushes under a desired geographic condition grow exponentially and pose a threat of contacting the conductor.
Another classification of Vegetation management program is determining danger trees or trees of interest.
As per ANSI standards, any tree that has the potential to contact a power or transmission line in the near future is considered a tree of interest. They are determined by an array of biological and. environmental factors like dead trees, weak branches, cracks, infection, and root damage.
Herbicides are chemical agents that are used to kill or inhibit the growth of unwanted plants like buckthorn.
These unwanted plants are generally fast-growing and can cause problems to lines and hinder access to facilitates.
That’s why the use of herbicides is efficient as they can reduce the growth of these unwanted plants or directly kill them. Plus, they have no effect on grass and other native vegetation, so the desired slow-growing shrubs prosper.
A direct answer to this would be, it depends. But traditionally, a trim cycle is performed every 3 to 8 years depending on and decided by an array of factors. Trim cycles are classified as a part of planned work because it needs to be done again and again after certain intervals.There is one more type of work under Vegetation management called reactive work.The simplest example of a reactive work would be a customer informing that vegetation is interfering with power or transmission lines.
Now, one can wonder how these things can happen if there are trim cycles in place?
The truth is that even after all the data and risk analysis, the growth and risk of vegetation is not entirely predictable. Moreover, there are multiple reasons why utilities struggle to maintain a healthy vegetation management program.Thus, the need for pruning can sometimes arise before the next trimming cycle.
To prevent this from happening, applications like Aptimize by Aplines uses satellite data to generate optimal maintenance scenarios. So, the vegetation can be controlled pro-actively.
Considering the millions of dollars of budget assigned to vegetation management by utilities, it’s a must to keep power outages at a minimum.
This is where data and AI can be really helpful.
With advancements in satellite technology, companies have started launching satellites that can segment vegetation by height and get precise and reliable data.
This data can then be used by AI to generate more accurate predictions about growth rates.
Furthermore, accurate & up-to-date satellite data can be combined with the traditional drone and on-ground data to obtain an even clearer picture of the risk posed by vegetation.
Vegetation management is a crucial part of any utility's attempts to keep power outages at a minimum.
Simply put, it is the act of keeping power and transmission lines clear of vegetation. Any vegetation that interests a Vegetation Management manager is deeply analyzed and judged before being pruned.
However, human judgment is sometimes not enough. This is where Alpines' Aptimize comes into play.
Aptimize is a breakthrough application that integrates various data, including satellite data, to assess the risk posed by vegetation. Moreover, it can generate optimal Vegetation Management programs for any given budget and allows you to prioritize interventions for optimal results.
With the Dashboard Builder: analyze your portfolio and understand the risk visually while creating a risk matrix with tables and creating dashboards, showcasing data through widgets.
Once the risk is understood, aggregate all your functional group assets, lines, poles, transformers, views aggregated by processors, geographically.
Create an Action plan: ramp up your decision making and prioritize to tackle all your monetized risks.
And finally, create a Maintenance scenario: reduce the risks, create the maintenance plans, and suggest an optimized maintenance plan all while maximizing ROI (ratio between maintenance cost and reduction of monetized risk). Using the Optimizer scenario, you can set budget constraints and dedicate the most optimal asset groups to send for maintenance.