Curious Conversations, a Research Podcast

Travis

What's the biggest threat to our power grid? I don't know about you, but I love keeping the lights on. So when I start to hear that folks are having doubts about the future sustainability of our power grid, well, I can get a little bit scared. You know, I'm not even sure what all the power grid entails, much less what the power grid of the future will look like related to microgrids, renewable energy, and even data centers. But thankfully, Virginia Tech's Ali Mehrizi-Sani is an expert in this very subject.

Ali

one of the questions about data centers is their load fluctuations because they can go from full power to maybe only ten percent of power and then back to eighty percent of power quite multiple times a second and that does put a strain on the on on the power system.

Travis (00:47)

he was exactly the person for me to talk to to help better understand the power grid and feel a little bit better about keeping my lights on in the future. I'm Travis Williams. And this is Virginia Tech's Curious Conversations.

Travis (01:05)

when I reached out to you, one of the reasons was because I had just read an article about the power grid and the possibility of it having some different troubles. And quite honestly, it got me kind of scared. and then I realized I'm not even really sure what they're talking about when they talk about the power grid. So I think maybe that might be a good place to start this conversation. When we talk about the power grid, what should I be thinking about? What should I have in my mind?

Ali (01:29)

I I actually like that as a starting point. I mean I really want to always get get back to the basics and and and the the foundational definitions. so so you like this question. when when we talk about the grid, we normally talk about the electric power generation and transmission system. So that means everything from different types of power plants, you can have nuclear, you can have thermal power plants, coal power plants and so on. Or you could of course have solar and and wind. So that's the generation side. And then you have the systems, essentially the transmission lines that you see when you travel along the roads that bring power from those power plants to load centers. Typically, this part, generation and transmission, is what we refer to when we talk about the grid. But of course, you probably have already noticed that there is a part missing here like from the big low load centers to the actual load, like that part that goes from because the substation, the part that goes from takes energy from substation down to let's say university, different buildings or or houses, there is that part that is part of the overall power system and we call that the distribution system. but when again when we talk about the grid, typically it's the generation and the transmission part of parts of

Travis (02:49)

And in America is the grid yeah, this is another thing that I'm just probably completely ignorant on. When we talk about the grid, are we talking about one thing that's completely connected, or are we talking about different things that are kind of their own pieces?

 

Ali (03:02)

That's another very good question. so our power system is actually interconnected. So when we talk about the like North American power system, the whole electric delivery system we have, while the US, even Canada, and parts of Mexico are physically connected to each other. Now, sometimes when we we talk about the grid, we refer to portions of the grid. So this whole grid that I talk about, so if you put an electron on the grid here in Virginia, that electron may actually travel all the way to to California. But in between we have what we call synchronous areas, and that's a bit of a technical term, but I can I can easily explain it. So the eastern part of the country everything is connected through A C lines and then the West West side of the country, everything is also connected through A C lines. And then Texas and parts of or most parts of Texas is also connected through A C lines. But then these different subsystems are connected through D C lines. So there is kind of that of hybrid system that we have. So sometimes when people talk about e a grid Maybe they talk about only the western part, which we call VEC, W E C C or the Eastern Interconnect EI. but everything eventually is connected to each other physically. It's just whether they're connected through A C lines or through D C lines.

Travis (04:36)

Yeah, that's really helpful for for someone like me that I don't know, maybe talks about this a lot, but doesn't really have a clear understanding. There's many times in my life where I use words and I'm like, am I actually using the right word here? Like, do I actually know what these words mean? so thank you for that.

Ali (04:47)

Yeah. Well we all do that. We all do that in different fields. Yeah.

Travis (04:52)

I'm glad I'm not the only one. Well, I'm I'm also curious, kind of in a similar vein, when we talk about grid blackouts, what are we talking about there generally?

Ali (05:02)

really power outages. Now you call a power outage a blackout if it's bigger in essentially geo geographical area. But otherwise, essentially a blackout is when a certain area is out of power for an extended period of time. and of course we never like blackouts. It's actually one of the main goals of system power system operators and utilities is to maintain the reliability of of power grid.

Sometimes I put it this way, I say as an infrastructure, the main goal of a utility is to make sure it's reliable and it's safe. Those goals, trump goals like making sure that everything is using the the highest and newest technology, but the the primary goal is reliability and safety of the power.

Travis (05:51)

that that is great to hear, as someone who just loves having power on. and

 

Ali (05:53)

You know.

Travis (05:55)

and every time it goes off has this like nervousness, like

Ali (05:59)

Yeah, I mean think think think about it this way. I mean we all really want to have a an extremely boring power system, right? You always want to you always want the power system to do the same thing. You flip the switch on and you want the lights to to to come on, right? You don't want to like morning you don't want to get up and and say well is the switch is the lights are going to come on when I flip the switch today, or what type of surprises will the grid have for me this day?

Travis (06:28)

Yeah, that definitely seems like one of those types of things where no news is good news. If we're not talking about it, probably great well, I'm curious what about our power grid and the current situation we're in with it? What mate make it more susceptible to blackouts, whether they be from severe weather or from from cyber attacks? But I've seem to be hearing more now than maybe I did years ago. but what is it about our our our grid that may Make it more susceptible now than maybe it has been in the past.

Ali (07:14)

so well we we somehow the power grid has has found its its way to mainstream discussions. So it I mean power system has always as as a big infrastructure that covers the whole United States, right? It it's al always been susceptible to weather, it's always been susceptible to physical attacks and and cyber attacks. but people are thinking about power system more consciously these days. Maybe I would say part of that is because, well, for the past maybe decade and a half, we have been talking about these new sorts of generation, like solar and renewables and med, right? Then to augment that, there's been discussions about these new types of loads that everybody is discussing, data centers, right? So and Any new load that you put on the system is going to require additional infrastructure. And infrastructure needs to remain safe, need needs to remain reliable, and we need to make sure again we we we are not we are not seeing those those blackouts. Now, if if you put let's say more data centers and actually it's not only data centers, any large load. for example we are talking about reshoring manufacturing, right? That that's gonna require a lot of electricity as well. we talk about fleet electrification, that's going to need a lot of electricity and power as well, right? So as we increase our reliance on electric power, naturally anything that disrupts the infrastructure that that disrupts the grid is going to be often more more impact on our lives. So it's natural that now we are more conscious about it, that we that we of course we want to we want to avoid those th those blackouts happen.

Travis (08:58)

Yeah, that makes sense. that it's just more maybe in the public discussion than maybe it has been in the past. Well, you mentioned data centers, and that was one of the things I was going to ask you. this that's one of the places that I've heard a lot about power grids. And so I'm I'm curious, what are some things that we're concerned about with the power grid when it comes to whether it be onshoring more manufacturing or or data centers or just an additional load? how do we how should we think about that and maybe what can we do about it?

Ali (09:28)

so I I mean data centers are actually quite interesting. First, I mean yes, of course there are additional load, but they probably one of the reasons that people talk a lot about them is first of all they are very concentrated, right? You have a lot of in power consumption in kind of concentrated in a very small geographical area, but at the same time, data centers are quite resource intensive, right? They use also water. They use they use land. And there's so many different different aspects about data centers that we have to coordinate at the same time. so so so that that's one of the main things that we and in in terms of the actually the type of load that data centers are We call them electronic loads. That means they can actually change quite fast. Traditionally the types of loads that we have had in the power system have been more electromechanical. Think of them as just electric motors, right? Motors I mean yes, of course they can spin fast, but that's still much slower compared to let's say how a CPU or an IC can can change its its its power one of the one of the questions about data centers is their load fluctuations because they can go from full power to maybe only ten percent of power and then back to eighty percent of power quite multiple times a second and that does put a strain on the on on the power system. That doesn't mean that we I mean th this is actually one of the research areas and just like any other technology, we are as the community we are working on ways to reduce the impact on on the power system and somehow manage it. but that is nevertheless one of the concerns and one of the questions about about data centers.

Travis (11:14)

Yeah, that's really interesting. and I don't know if this is similar or not, but it reminds me when my parents used to get mad at me about flicking the light switch up and down because it was just like changing

Ali (11:22)

Yeah.

Travis (11:23)

things really fast. Is it like that? In a way, like

Ali (11:26)

Well, your parents probably didn't like you doing that too much first because I mean of course it could be annoying, right? I mean lights getting on and off fast. And then

Travis (11:32)

That's true. Yeah.

Ali (11:35)

it would also those older lights they had the the the bulbs, they had a limited number of on and off operations that they could they could go through. So the more you did that essentially that means you you killed the the the light bulb earlier than we're supposed to for the the for the data centers, those fluctuations are I mean our power system is actually very very reliable already. But one of the things that could happen, and we have had instances of this happen before, is because data centers are quite sensitive to the power that they receive.

They they need to get their power at a certain voltage, certain frequency. And again, the the power grid most of the time, ninety-nine point nine nine nine percent of the time does a very good job of providing power within those prescribed limits. But because data centers are electronics, they can actually be sensitive when you essentially go out of that band just a bit. And what happens is they switch from power grid to their backup power UPS. And when a lot of data centers do that, the impact on the power grid could cause kind of some rippling reliability events. We have had a lighter example of this only this I think it was only July. So essentially there was a fault on one of the transmission lines in northern Virginia.

And of course, with the other fault, there's going to be some fluctuations in the voltage and and frequency. Most of the time is actually okay because the system essentially comes back to the to the steady state to those limits fairly soon. In that case, actually the system did come back to the prescribed limits very soon, but data centers in the area were quite sensitive. So about three gigawatts of power that they consumed went offline and was transferred to the to the backup power. Now three gigawatts at the time was about one percent of the the PJMs load. it's a lot but the grid is also very strong so it didn't really cause too much too much problem for the grid. Now that event itself was okay but then what it tells you is Maybe as the number of data centers that we have on the grid increases, let's say two years from now, if a similar event happens, then if instead of three gigawatts we get maybe ten gigawatts of power disconnected, would our grid still be able to to manage that that load drop? two years ago, actually instead of three gigawatts, we had one gigawatt of load load drop that happened. And again, the system remains stable and it was actually dominion system and they could manage it very well. but the question is what what do we need to do to make sure it stays this way? Whether we need more regulations, whether we need certain specifications, right through requirements. Those are actually all active areas of discussion in the technical community.

Travis (14:38)

Yeah, that's really interesting. I want to ask you another question that just comes purely from my ignorance. When something like that happens, or maybe like we talked about blackouts earlier was when those happen, what generally is is happening? Did something break? Did a wire break? Did a transformer blow? what happened?

Ali (14:55)

It could be it could be any of those. so sometimes let's say you have a strong wind and a tree hits one of the transmission lines, it it either creates another path for the current. So instead of the current or the electrons go through the transmission line, it could actually find another way and go through grant. That could change the voltage, that could change the power that's being transmitted through the line. sometimes the line could actually break. that's another another thing that could could happen. And you mentioned maybe a transformer that that that could be something that causes causes a problem or a fault as well. Sometimes maybe an insulation in inside a transformer could fail. Up so all of these can happen. Again, it's a it's an engineering system, it's a physical system, right? we try to be very reliable and we are, but but doesn't mean that we are we get to hundred percent, right? There's always certain kind of the faults that can that can happen. But the system knows that they can happen. The system is actually designed for those type of things. what we are now experiencing is the that as a result of those disturbances that you see large amounts of load essentially getting disconnected. and that's something relatively new that we are now experiencing.

Travis (16:11)

Well, you mentioned renewables earlier. And so I'm curious how do renewables, solar, wind, how do those fit into the equation of our grid? And and are we already benefiting from some of them? I guess just like what what's their role when it comes to our grid?

Ali (16:27)

so I mean we we we in a sense need a lot of electricity, a lot of power as we increase the amount of load that we have on on on the grid, right? So one of the ways that we get more power is I mean renewable as a as a new category, but but solar and and wind essentially provide that that much power. Now one thing about solar and wind is typically you don't actually control how much power they they provide, right? I mean you're really at the mercy of nature. If it's a cloudy day, well good luck with your PV generation. Or if you're not getting much much wind in a day, then or if the wind is too strong, either case, the wind turbines are not gonna not gonna generate any any any power. I mean one case you just lock them because because otherwise they would be damaged. And if of course if there's not much not much wind, there's not much energy to be extracted from from air. so so typically we we kind of pair the energy that we get the power that we get from renewables from other with other sources that we can actually control. Think of let's say hydropower. Hydropower you can open and close the the gates and depending on how you control it, you can actually generate the amount of power that you you're gonna be you're gonna be generating in in in the the hydroplant. So as a combination of these different resources, we make sure that at each instant we provide enough power to floor loads.

Travis (17:57)

That makes a lot of sense to combine the ones you can't control with the ones you can't control.

Ali (18:01)

Yeah.

Travis (18:02)

I I've tried that tactic when it comes to coaching my son's peewee basketball team. put the ki put the kids

Ali (18:08)

That makes a lot of sense to the

Travis (18:09)

that will listen with the ones that, you know, may struggle a little bit in that area and you know, and it all works out.

Ali (18:15)

Yeah.

Travis (18:16)

Well, I know one of the other things that you study are microgrids.

Ali (18:19)

Mm hmm.

Travis (18:20)

It sounds to me just by the words that there are smaller versions of power grids, but I would love for you to maybe answer that question. What are what are microgrids and how do they fit into the equation that is our power?

Ali (18:31)

So yeah, I mean microgrids as the as the term implies there are smaller versions of power grid. But what I would caution people to to note is that that doesn't mean that the that kind of controlling and operating a microgrid is actually easier than than a full grid. because you have a smaller scale of everything, making sure that power balance between how much power you generate and how much power your loads are gonna be consuming, maintaining that balance is actually more difficult.

You have fewer resources, so any small disturbance can actually cause quite a quite a bit of fluctuations in your power, voltage, frequency, and so on. So some of the control questions are actually more more difficult. Economies of scale is gonna be also a bit more difficult to make sure. So sometimes I would say probably a lot of times, actually operating a micro grid is more expensive than operating the the full grid. And This is the reason microgrids typically have very niche applications. So one example is well, when you don't actually have a grid. So you try to essentially create your own small power grid, which we we then call a micro grid. But a lot of microgrids actually operate and can can can exist when the grid is also present. So in those cases, The idea is that we draw power from the grid as much as possible because that's just cheaper, right? And provides more control and reliability. but then if the quality of the utility grid deteriorates, then in those cases we're gonna disconnect and operate as a standalone microgrid. Applications could be, for example, military installations. Again, when you have very high reliability requirements.

Hospitals are another example. And I actually already mentioned another example of data centers. I mean I I mentioned that in those events the the when when the power grid was going through certain flu fluctuations, then the data centers disconnected from the grid and then they switched to backup power. That means that they actually had a macro grid, right? Most of the time they do draw power from the grid because again it's much cheaper than operating their own say diesel generators. But if the quality of power from the grid, even for short amounts durations, deteriorates, then they're gonna disconnect and operate as as microgrid. So in those cases data centers are actually another application for microgrids. We do joke that I mean microgrids are supposed to be small for data centers, those I mean they they draw a tremendous amount of the power. So so those are going to be huge microgrids. But in in terms of in in terms of operation and the technical requirements, they operate pretty much the same as the traditional microgrids.

Travis (21:18)

Yeah. Well maybe we can call them like medium sized grids. We can come up with like another another term for it.

Ali (21:22)

Mini to it? Yeah.

Travis (21:24)

Well that's well, one of the things I also wanted to ask you about is we live more and more in a in a digital world and in many places that opens us up to different types of cyber attacks. So I I'm just curious with our electrical grid, what are some things that we can do or should think about doing to maybe harden us against some of that threat?

Ali (21:45)

so it's actually quite quite interesting the way that a power system was developed. A lot of this was based on trust. So a lot of kind of the traditional controls and optimizations actually did not see the need for encryption or making sure there is proper authentication. Now the good news is that that is changing and that has changed to a to a lot of extent already.

But as we see more communication in power system and we need communication because of course we want to know the status of remote switches, the status of remote power plants, and then we want to optimize them, right? I mean if if you know if you have a full picture of your system, you can utilize your resources much better, much much more optimally. So that means we need we need more communication. And it this is actually one of the research areas that we are working on in collaboration with colleagues in the wireless at VT. we're looking at how we can use different generations of communication. 5G is the one of the things that we are actively working on right now, how we can use f secure five G communication for improving the performance of the of the power grid. We have been looking at control, we have been looking at monitoring and and and protection of of the grid. So utilising more secure and autin authenticated types of communication is is one of the one of the major ways that we can improve power system respected to its cybersecurity.

Travis (23:14)

I I guess maybe just to wind the conversation down. What could the average person do to maybe help better take care of the electrical grid? Or is there anything that I what can I do to help the grid?

Ali (23:26)

That that's a very very interesting question, got me thinking. So of of course power grid can get very technical. but one of the things that everyone can consider is different kind of versions of demand response programs. Now I'm gonna explain what that means and I'm actually participating in one. So there are certain periods that grid is under stress.

 

And under stress means you have a lot of power demand. We actually had one of those instances maybe two, three weeks ago. I was traveling but I got notifications on my on my on my phone. it it was very hot here in Blacksburg. And then I mean we can generate a lot of power, but at the same time the amount of power that we can generate is quite limited, and also the amount of power that we can transmit is quite limited. So the notification that was going out was and university actually did part of that as well was hey, now that the amount of power we can generate is limited, and within the constraints of reliability and so on, then let's reduce some of our load, some of our consumption. So so for example, in my house, my my thermostats participate in AEP Appalachian power program. So when there is too much demand, too much power need from the from the grid, they actually automatically adjust the temperature maybe two or three degrees up or down. So in that in that way they reduce the amount of power they require from the grid. So and two weeks ago similar thing university as a whole did as well to participate in in those type of programs. So that's that's actually something quite inter i I I think APCO actually provides some financial incentive for that as well, but people can check check that out on their website. But but that's that's one of the things that I think in in those periods th they they do happen they don't happen very often but in those cases that's something that we can do to conserve some some power.

Travis (25:28)

Yeah. Well that sound that sounds awesome and I appreciate you sharing that. well thank you so much for for talking to me. I feel better about that article I read about how the power grid was gonna fail after talking to you. I feel much better it's much less a doom and gloom than I was than I entered

Ali (25:40)

Yeah.

Travis (25:43)

the conversation with. So thank you for that.

Ali (25:45)

I'm glad they could help.

Travis (25:46)

Yeah.