The Benefits of Non-Contact Grid Monitoring Solutions: A Conversation With Hudson Gilmer from LineVision
image credit: Hudson Gilmer
- Jan 23, 2019 4:52 pm GMT
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Grid monitoring has come into sharp focus after news of PG&E’s bankruptcy filing. California’s forest fires, which were responsible for massive physical and liability damage, were largely the result of a grid architecture unable to react quickly to changing circumstances.
Massachusetts-based LineVision, Inc., believes it has found a solution to the problem. “PG&E’s bankruptcy is a direct result of the dangers of an unmonitored line, which caused these horrible forest fires,” says Hudson Gilmer, CEO of LineVision. The company, which was spun out of Genscape last year, completed a $2 million funding round earlier this month to scale its operations.
LineVision’s core technology consists of an EMF and Optical sensor that helps utilities monitor a grid.
According to Gilmer, LineVision’s systems enable grid operators to increase line capacity by between 15% to 40%. He predicts that it will become “unacceptable practice” to operate unmonitored transmission lines in the next five years. “The benefits (of installing monitoring solutions) are so compelling and the cons are relatively inexpensive,” he explains.
To that end, LineVision recently co-authored a paper with PJM Interconnection to analyze the economics of installing a dynamic line rating system (DLR) for grid monitoring. “..the resulting economic impact showed that the additional capacity provided in the DLR case led to a net congestion saving of over $4 million in the one-year study period,” the paper concluded. Payback period for installation costs of $500,000 would be approximately two months of operational use.
Here is a lightly edited conversation with Gilmer about LineVision
How is LineVision’s technology different from that of Genscape?
One of the problems with older dynamic line rating technology was that it had to be mounted on the conductor itself. That process requires either scheduling an outage or doing live line work. The latter carries safety risks and requires specialized equipment. Genscape pioneered non-contact sensors that used electromagnetic field monitoring (EMF) which can be used to carry out the work.
Within LineVision, we have developed a second sensor that uses a scanning laser device that measures the physical position of a conductor. The two sensors together provide incredibly accurate information about line load and its physical position. The beauty of this approach is also that it is non-contact. There is no outage required and no bucket trucks to be deployed. The work can be completed in a couple of hours. What’s more, our system allows utilities to “see” all lines, instead of having to pick just one.
I read an article recently, which outlined problems with installing sensor technology on the grid. Among the problems mentioned was finite physical space on poles. Is this a foreseeable problem for LineVision’s systems?
LineVision is not focused on distribution lines. We are more focused on high voltage kilowatt transmission lines. Typically, our system would be mounted 3 meters up on the tower, high enough so that it is out of reach of anyone if they wanted to mess with it. We are very flexible in terms of where it (the sensor) can be located. As such, we don’t see that as an issue.
What, according to you, are the drawbacks of current monitoring systems implemented at the grid level?
When we talked to utilities, we found that they are blind to what’s happening on the lines themselves. They have to rely on the model of a grid architecture that was built 20-40 years ago. While they are trying to get end-to-end visibility across their systems, utilities do most of their monitoring within the substation, where they have their transformers and other equipment.
The most important drawback issue relates to safety. PG&E’s bankruptcy is a direct result of an unmonitored line, which caused the horrible forest fires. We feel adding monitoring has compelling cost benefits, reliability benefits and adds grid visibility for utilities. It also allows utilities to increase capacity on existing lines by 15 to 40 percent.
How does DLR enable integration of renewable energy into the grid?
The current grid is really designed for a different generation mix than what we see going forward. For example, the current architecture is designed to deliver power from large central plants, such as coal and nuclear. But coal is being retired and replaced by renewable energy sources in the grid. So, the grid is forced to perform a different task. We believe that adding flexibility and control it provides, gives it advantages in integrating renewables. Right now, you have a very static grid. DLR allows the grid to be more flexible to match renewable energy generation.
Can you give me an example of how your systems enable flexibility in renewable energy grid capacity?
The biggest benefit is for plants using wind energy. Wind is one of the biggest causes of congestion in the grid today. It tends to cluster in areas such as the Texas Panhandle and Midwest. In a lot of cases, when those turbines are really spinning there’s not enough grid capacity to deliver that free power to customers. The problem is that utilities rate line systems on a worst-case condition of ambient conditions. They assume no wind and relatively high temperatures. In reality, 98% of the time, conditions are better than the worst-case condition anticipated by the utilities. The line is actually capable of safely carrying more power than the traditional static rating.
By adding monitoring onto the line, we are able to ease the line’s sag. The system relies on the condition that a hot line will sag lower than a cool line will. What we want to do is ensure that the line doesn’t exceed its maximum temperature. You can see monitored lines and say “hey, the wind is cooling this line and you can safely put more power through it.” The beauty of it is that when there’s enough wind spinning the turbine (and heating it), there’s also enough wind cooling the line. You can offer a dynamic rating that’s much higher than a static rating.
Can you briefly explain how LineVision’s systems work?
Essentially, utilities would take the dynamic rating we feed them and pass that to the operator. All of the ISOs have been very supportive of dynamic line monitoring. We are not allowed to name names but I can say that we’ve worked with four of the top 10 utilities in the country. Granted the scope of our applications has been fairly limited while they become familiar with the tech, it is still showing very strong growth.
Since the sensors are placed outside, are they susceptible to physical damage from the weather?
Genscape has deployed 5,000 of these sensors worldwide and the sensors have been operating for ten years or more. We’ve seen very little damage and the Genscape sensors are much more accessible (in terms of physical location and height) than LineVision sensors. Our sensors also have weatherproof enclosures and record weather data. So even in a worst-case scenario, we can still calculate ratings based on the weather data that we are getting for a given site. If all else fails, utilities can revert back to static ratings.
What about cybersecurity?
In fact, we see an opportunity to use our systems to improve cybersecurity of the network because it can record differences between SCADA systems and our system. We have already done work with defense agencies to detect spoofing of parallel sensor systems. Because we have EMF sensors, we are able to monitor things on the grid independently from the utility’s own sensors.
Tell me about your future plans
Right now, we are focused on expanding the team. We really believe two fundamental things. One is that the idea of an unmonitored transmission line is going to become unacceptable in the future. The second thing we believe is that our approach of non-contact monitoring is superior to existing monitoring methods used by utilities. It is cheaper and more accurate than current monitoring methods because it reduces liability and safety costs.
The general message that we’d like to put out there is that this is a very inexpensive solution relative to the cost of transmission line and safety issues. Part of it is also about utilization and optimizing asset management strategy by monitoring asset health. Because of these reasons, we see a tremendous global market opportunity to improve reliability. There is load growth of more than 10 percent in the developing world and several utilities there are interested in our technology. We are working with them in India and Costa Rica.