Sentient Energy’s Grid Edge Control product line is a cutting-edge solution that is designed to solve the problems associated with power distribution on today’s grid. In an exclusive Energy Central interview with Sree Gutta, the product manager for the Grid Edge Control product line, and Steven Watt, a member of Sentient Energy’s product marketing team, they provided insights into low voltage VAR control technology and its benefits.
Sentient Energy’s Grid Edge Control product line is a game-changing technology that offers a range of benefits to utilities looking to improve their energy efficiency and reduce peak demand. The technology is easy to install and provides utilities with better visibility into the system, allowing them to make informed decisions about how best to optimize the system. With the increasing demand for energy and the need to meet zero-carbon emission goals, Grid Edge Control is the perfect solution for utilities looking to modernize their grid and support the integration of more DERs into the system.
Matt Chester: Give me the cliff notes of the Grid Energy Control technology. What problems is it solving and how is it doing so?
Sree Gutta: When we talk about the grid itself, there are a lot of things that are going on these days with modernization. People are always thinking about the medium voltage side and one of the things that people don't think about is the low voltage distribution side. And so, there is no visibility at that level and there is also potential for more energy savings by utilizing the low voltage side.
By adding Grid Edge Control, our dynamic VAR control solution, utilities install a hardware device on the distribution side of the low voltage transformer allowing them to raise the low voltage points. And so, what will that do? It will help further reduce the voltage at the feeder level itself. There are several low voltage points throughout the distribution system and if the utilities are able to raise these low voltage points, they can lower the voltage further at the substation level and still meet minimum voltage limits. Say, for example, if there was a big mansion or industrial facility drawing more voltage. You have to raise the voltage of the total medium voltage feeder itself, but if you are able to raise the voltage levels at those problem points, you can lower the voltage of the feeder. That's what we're doing. We're helping lower the voltage of the feeder even further so that there is more potential for energy saving and also peak demand reduction. There are other applications for Grid Edge Control, but that's the main application.
Steven Watt: To add to this, what's really unique about this solution is that when you provide VAR support at the distribution transformer, you're raising the low points rather than bringing up the whole voltage curve. That means you're essentially compressing the voltage profile from the bottom up and now you're creating some space above that 114 Volt lower limit. And so, you can do with it what you want- you can use it as margin in case in case there's new load that pulls voltage down or you can use it to realize some energy savings by dropping voltage at the substation.
So, what's really interesting about the solution is that in addition to energy efficiency, it also helps you to solve some new problems that are being created by DER hosting. If you look at EVs, they are one of these new loads that's pulling the voltage down. Grid Edge control is going to help you because it's creating more lower voltage margin that EV charging will require.
The other opportunity that's not as obvious is over voltage issues associated with hosting solar. When you have a lot of solar on a circuit, your voltage is going to tend to rise higher than you'd like, and it may exceed the upper 126 Volt limit. If you have lower voltage margin you can drop the voltage and create upper margin for the solar so you can increase solar hosting. To me I think what's really clever about Grid Edge control is when you clean up the voltage profile at the distribution transformer, you solve multiple problems. You can get more efficiency if you want. You can get more margin for EVs. Or you can get more margin at the upper limit for solar hosting. So, I think that's why it’s a unique opportunity for utilities.
MC: You mentioned a couple of technologies there that will kind of hint at the answer to this next question, which is why now? Why is today the right time and this the right utility landscape to deploy Grid Edge Control?
SG: Energy efficiency standards are always there for the utility. Every year, many utilities have goals of saving additional energy, so they have to find new ways to save. Also, multiple states having zero carbon emission goals, which challenges utilities to look into how they can achieve these goals too. Utilities are looking into technologies like Grid Edge Control to support EV and solar PV penetration into the system, and these technologies are growing exponentially every year. There is only so much DER hosting that feeders can handle and changing the distribution system is not easy. Utilities have to use technology to enable more penetration of solar PV and EV charging into the system.
SW: If I was a utility, I would deploy Grid Edge Control and then use it for multiple purposes. So, if I have a feeder that has a lot of solar on it, I'd use Grid Edge control to create upper margin and avoid overvoltage problems. Then I might have another substation or set of circuits that have a lot of EV, so I'd use it there to maintain minimum voltage for EV. And then on the other circuits that don’t have a lot of EVs or solar, then I’d use it for energy efficiency and save energy and money and get my carbon footprint down a little bit. So, I think what's cool about Grid Edge Control. It allows the utility to address multiple problems based on what's going on for each circuit.
MC: I'm curious if you can walk me through the process of rolling this technology out and integrating it to a specific utility. What does that rollout process look like and how long does it take?
SG: Typically, the way we approach any project is to sit down with the customer, study their load profile and their feeders, and then provide them with suggestions for implementing dynamic VAR control. We gather the SCADA data, the ADMS data, and whatever else the customer can provide. We do a study for them and provide a cost estimate. From there, we typically do a pilot with the customer on a feeder they pick or we suggest. It can be any number of units based on the feeder, based on the loading, and based on their goals for energy savings or peak demand reduction. Then once the pilot is done, usually around four to eight weeks, we can show them the incremental savings that are provided. Once everybody is happy with the results, we then move into production.
The installation process is very simple, I would say because it's basically a 50-pound device mounted on the pole. A few connections need to be made on the secondary side of the transformer, but the installation is really quick and the device itself has integrated communications. The dynamic VAR control devices connect into our grid edge management software, GEMS, to enable fleet management and remote visibility of edge voltage data. If the customer wants, they can also link data into their SCADA system. So that's how the typical installation process runs.
MC: Thanks for walking through that process. And once that process is complete, how do you measure success?
SW: If you're a utility, you'd want to keep looking at voltage measurements. You take a snapshot of the system, find out where the low points are, and then put the low voltage VAR control there and now you're boosting the voltage profile. You drop your voltage and now you're saving some money.
But things change! Like we were talking about before with EV charging, you might have a transformer that all of a sudden has three EV chargers on it, and that becomes a low point when it wasn't a few months ago. So, I think the utility wants to keep looking at voltage measurement and making sure they're not dipping below the 114 Volt minimum as things change on their system, adding more of our dynamic control where it's needed. For the transformers that have our solution on them, they can see the voltage at that transformer, which makes it really easy. For the transformers that don't have our product on it, utilities probably look at their AMI data. If they don't have voltage info through AMI maybe they have it through some other system. The short answer is that I think utilities want to put low voltage VAR control in place and keep monitoring and tuning.
MC: Have you run into any resistance from utilities in having them embrace the technology or are they usually all on board upon hearing what the technology can accomplish?
SG: There is definitely some educating when selling that needs to happen because this is a newer technology. We've had good success with customers who really understood the product, such as Xcel Energy who is one of our biggest customers with more than 3000 devices installed in the field. But when we are going to a newer utility who has a challenge, we need to explain that this technology is going to help them. So, there is definitely that learning curve or teaching curve with the utilities. Luckily, the pilot really speaks for itself and once we do the analysis from the data they give us and then once we do the pilot, they see the results and that is when customers really believe because they really see the benefit of the product itself.
With Xcel, we had 87 devices deployed and the total energy savings were 3.3%. Of that, 1.59% came from the incremental saving that were provided by the low voltage VAR control installed, so 50% of the savings are provided by the low voltage VAR control. And then there is another feeder where we did peak demand reduction and there was a 4.2% peak demand reduction in total, and of that 2% was the incremental savings provided by the low voltage VAR control.
SW: Another way to think about it is if you're in a utility and you're managing the VVO program, you could basically get double the savings by going a little further and implementing the dynamic VAR control on the on the low side of the distribution transformers.
MC: Great, well is there any final message you want to be sure to include in this conversation that we haven’t yet touched upon?
SG: I just want to highlight the fact that this technology, although it sounds new, has been around for more than 10 years. We have a lot of expertise and there are more than 10,000 devices installed in the field and we have a lot of use cases like energy savings, peak demand reduction, helping with more EV and solar PV penetration. We also have applications where it's also being used to help with the power quality. So, we have experience with a lot of applications already with our Grid Edge Control solution.