How do electricity grid operators make sure there’s always enough energy to meet demand? Energy expert Julie McNamara reveals the painfully wasteful answer.
In this episode
- Colleen asks about the extra load that heat adds to the electric grid
- Julie explains what a more climate conscious energy system would look like
- Julie and Colleen talk about how complicated the job of a grid operator is
- Julie tells us why her dinner party invitations are dwindling
Timing and cues
- Opener (0:00-0:33)
- Intro (0:33-2:17)
- Interview part 1 (2:17-12:30)
- Break (12:30-13:38)
- Interview part 2 (13:38-23:54)
- Science FTW Throw (23:54-24:06)
- Science FTW (24:06-27:36)
- Outro (27:36-28:36)
Colleen: So, Julie, thanks for joining me on the podcast.
Julie: I'm so glad to be here.
Colleen: So, I'm not sure how often the energy grid comes up in casual conversations with your friends, but I tell you that in my life, the number is zero. It's the poster child of out of sight, out of mind, but it's actually tremendously important. So, can you describe the electricity grid in a way that the average person can kinda get a picture of how it works?
Julie: Sure. So the whole goal of the power grid is to get electricity from where it's generated to the people who use it. That means getting from a power plant to that socket in your home. So we have these power plants then transmission lines that bring power over often long distances, and then to smaller lines like you see around your neighborhood, which then eventually come to your home.
Colleen: So are all grids equal or are some better than others?
Julie: Sure. So the grid's been in a state of transition that we haven't seen in many, many decades moving from a model of these large centralized generators, these very massive power plants, to more distributed generation. And that means seeing wind farms and solar farms closer to your homes, on rooftops all around the country. With that shift towards decentralized power, we actually increase the resilience of the grid, because any single outage or fault on the system is less likely to cause a massive power event.
Colleen: So, who actually runs the grid day to day?
Julie: There are some parts of the country where utilities participate in markets, so they're sharing operations over broader regions. There are other parts of the country where utilities are very localized. And then within those different areas there are also local power, municipal power, and co-ops.
Colleen: So it's basically all over the place. You've got a whole range of different systems or ways of operating.
Julie: That's right. But there are still some core operating principles, and each region of the grid has to align with these. There's the National Electric Reliability Corporation and the Federal Energy Regulatory Commission. Both set standards and check on the reliability of the grid. So, a lot of operations have to meet such standards. And that comes into play when we get to, especially, some of these high risk events and how to prepare for and prevent those.
Colleen: So what's an example of a high risk event?
Julie: Heat waves. So that's when you get to these situations where you're having increased demand on the grid at the same time that you have the increased chance of different pieces of equipment failing. And it's in those situations when you're facing these dueling challenges that you might lose power. And the whole goal is to keep power online 24/7, 365.
Colleen: How robust is the system? I think most people think, "I flip my switch in my house and the electricity comes on." Is there reserve power just sitting waiting for these moments of extreme heat?
Julie: Yeah, there are. And there are reserves at a lot of different levels, from, you know, minute by minute, to day by day, to seasons, to on an annual basis. Because the way that the grid is planned is we use different amounts of power over the course of a day, over the course of a year, at different seasons. Right? So in the middle of summer you are running your air conditioning, in the fall, not so, so electricity load fluctuates. Grid planners are prepared for that. So they look at weather forecast, for example, and they know how many resources they need to be prepared to have come online at a moment's notice.
Some power plants are just ready and waiting right in the wings. Some take a little bit longer to call on. The newer resources we've been bringing online, things like solar, wind, and batteries can actually respond very quickly to these types of things. In the past, we've relied, and still do, on natural gas power plants, which also some of these power plants can ramp up much faster than traditional coal or nuclear plants.
Colleen: So basically, you're saying that there are plants that are just sitting at the ready. So, if a heat wave is forecast, then they get up and running, they fire up and are ready go?
Julie: That's right. So there are markets designed for this. A lot of this is based on a day ahead market where there's a forecast for how much electricity will be needed. These power plants will bid in. And then real-time markets, which are really looking at if they underestimated or overestimated making those minor adjustments, day of. So especially in things like heat waves, there are some power plants that only run a few times a year. That's incredibly inefficient. It's really costly, right? You're keeping these big power plants around, sometimes small, just to be able to meet these peak events. But it's absolutely the case that the grid has historically been designed to serve customers. So, to meet demand where it is. If you turn that switch, if you fire up that air conditioner, the grid is there to meet demand.
Colleen: Let's talk a little bit about, with renewable energy now gaining momentum, how will solar, wind, battery power, change the system?
Julie: So this system that we've historically used and relied upon is incredibly costly and inefficient. As I was saying, we're just keeping these power plants around to meet a few hours a few days a year. As we pivot to these cleaner resources, especially things like solar plus storage, they can directly replace those natural gas peaker plants. Except not only can they meet those few hours a year, they can contribute year round, which means not only are they much more cost effective, they're also a lot cleaner.
One of the challenges with peaker plants is that they are often located in communities, and on high heat days, there is very bad air quality, some of the worst air quality days of the year. And at that same time, you're powering up...one whole class of these peaker plants are actually the equivalent of jet engines. So you're bolting a jet engine to the ground and you're firing it up right at these bad air quality days. That's a terrible mix. It's costly, and it's bad for public health. So being able to replace those peaker plants with these clean resources that can benefit communities the whole year round, that's the better way to go.
Colleen: And the definition of a peaker plant is this plant that just comes on at those times, those few times in the year when needed.
Julie: That's right. They're all targeting that peak period of the day.
Colleen: Is being a grid operator a stressful job?
Julie: I have to imagine. You see these pictures of their operating rooms and they've got screens all over the place. The power grid is the backbone of all our critical services, right, everything relies on electricity when you follow that thread far enough back. So when the power goes out, it's a real crisis. So one of the most important things operators can do is not only ensure that, right, the power stays on, that's their number one goal. But they have these remote operation centers, right? They have their own resilience plans, just to be sure that they're able to manage outages themselves.
Colleen: As we're recording today, it's quite hot here in the Boston area.
Julie: That it is.
Colleen: We're having another...I'm not sure it's gonna qualify as a heat wave, but a few days of above 90 degree temperatures. How did the grid manage with our last couple of heat waves?
Julie: Overall, the grid did pretty well. In a heat wave, the grid is stressed from really two sides. There is the increased electricity use from all these additional air conditioners coming online, fans, refrigerators running harder. But then there's also the stress on the grid components themselves.
And that hits every facet of the grid, starting with power plants where these coal plants, nuclear, natural gas that rely on water for cooling. When water gets warmer, they're less able to cool their systems. And in fact, we've seen in past events when the water gets too warm, they have to shut down operations entirely. So that's taking some of your most important power plants and taking offline exactly when you need them most. Then you have these transmission lines, which those are the lines that convey electricity long distances. They are less efficient in high heat, so they can't carry as much electricity. They also run the risk of sagging as it gets warmer and more electricity comes through them. When they sag, they risk faulting. That can take a line off, then that can stop, right, the flow of electricity. And if the grid operators aren't carefully managing that situation, it can quickly spiral into a huge event.
The 2003 Northeast blackout was an example of that, where just a single line eventually triggered a massive cascading outage event that got 50 million customers across the Northeast. Of course, after the 2003 Northeast blackout, a lot of new standards and operating procedures were put in place that helped protect us from such a thing happening again.
Colleen: So that raises another question for me. When something happens en route from power plant to my electric switch, do they know immediately what has happened and where it is?
Julie: They're getting better at it and better able to quickly reroute electricity so any given challenge with the grid doesn't take the whole thing down. And this is something that grid operators plan for. So it's not just, do we have enough power generators to meet peak electricity demand? But also, can we meet peak electricity demand if our largest power plant goes down? If a very important transmission line goes down, can we still manage those outage events? And that's why we still have a lot more resources available than we actually expect to need.
Colleen: So how do power grids maintain reliability in a heat wave?
Julie: So this is a multistep process, starting from long range planning that spans years out. That's looking at forecasts for how much electricity is anticipated to be on the system, needed in those peak events, and ensuring that there are enough power generators available to meet that. The power grid is a large interconnected machine, and it's running all the time, which means that it needs maintenance. There are parts that need to be replaced. So when it comes to infrastructure planning, ensuring that these fixes, if say a power plant needs to go down for a bit, or if a transmission line needs to be replaced, doing that in what we call shoulder seasons. The spring and the fall when less electricity is needed, so there's more slack on the system.
Then, though, there's still some maintenance events that require longer periods. So it's staggering those to ensure there aren't too many overlapping, which would preclude the ability to meet peak demand during summer. There's also the case that power equipment fails, right? And you can have these unexpected events, and making sure you have enough backup power in place as well as planning for how to mitigate, mitigate the effects of such an unexpected outage. Then there's forecasting. Weather forecasters are incredibly important to grid operators, because they're the ones who say, "Well, we expect, in a couple of days, that the weather is going up." And then as that day approaches, that's projecting forecasted demand, and then signaling how much electricity will be needed by generators.
And then when the actual heat wave arrives, power operators are firing up peaker plants. They are bringing their least used resources online. They're also looking to neighboring regions which may not also be suffering such high weather to use electricity from them. And then they're calling on customers themselves to reduce usage. That can be in the form of demand response programs, where say an industrial customer doesn't actually need to be running all of their systems at that given time. Or that can be in programs where, say, big box stores turn off every other bank of light, or smart thermostats are turned up a degree or two, which, you know, for any given person, not a big change, but across the grid as a whole, makes a really big difference. So that's an incredibly important and effective solution.
Colleen: So when they're planning, looking out a few years, are grid operators or managers taking into account climate change, or do they do their projections based on, you know, what has happened in the last five years?
Julie: Yeah, so it's often a retrospective. And one of the ways we've long run up against challenges in that is the fact that energy efficiency standards have been increasingly stringent and really making great strides in reducing electricity use. We've also begun decoupling our general economy from electricity use. Where utility is long planned for steadily increasing use, we've actually been long showing that that use has been dropping off, which all highlights the importance of thinking about all the different elements at play. Because now as we add electric vehicles to the system, as we anticipate changing climate conditions, that also needs to be factored in. Because on the same side as we anticipate extreme heat, there are areas where there will be less of a need for electricity use in the winter.
Colleen: So, Julie, if I gave you a blank slate and said, "Here's a whole new system that you could develop," what are the first three things you would do?
Julie: So here's the thing. We don't have a blank slate available to us. And it's really important to reckon with the system that we have. With a blank slate, build a decentralized system where the infrastructure is planning for climate impacts from the start, where foresight is the name of the game, where renewables are integrated fully and completely, and the system is planning for that. But the system that we have today requires a different set of priorities because we have to begin from where we are and build from there.
Colleen: It's like a patchwork.
Julie: It is. It is. And, you know, a lot of grid infrastructure is intended to last decades and decades, and it's expensive, and it's paid for by rate payers, right? Your electricity bill, your natural gas bill. So, every investment that we make has to be thoughtfully, intentionally built. That's not traditionally been the case. But the more that we know about climate impacts, the more we know we have to factor them in to all climate and to all infrastructure so that it's climate resilient, climate smart.
Colleen: So, Julie, what got you hooked on the electricity grid?
Julie: Well, I think so much of the electricity grid is where the rubber meets the road for beginning our progress, furthering our progress on climate change. It's a complex system, but affects every facet of everyday life, and it's so important. And these decisions have long been made in closed room. It's very hard to influence the system. And one of the things that I think we really try to do here is ensure that these policies that will affect decisions and investments that will last many decades into the future are thoughtful, are considerate of changing circumstances, and are really in the best interest of people in the environment.
Colleen: The grid is overwhelming. Climate change is overwhelming. It's hard to feel like you can make any difference. Are there things that the average person can do?
Julie: At every step of the grid there are challenges that we face and also opportunities that we can take advantage of. And I think especially when it comes to individuals, that comes down to how we use electricity. There are choices we can make and then there are choices we do not have the power to make, unless router policies bring them online. And here I'm really thinking about, for example, the energy efficiency of air conditioning equipment. Air conditioners are widely used in the U.S., less widely used globally, but we know that with extreme heat rising from climate change, air conditioner use will be skyrocketing.
The single most important thing we can do is make sure that there is a rapid and aggressive set of standards for lowering the energy use of air conditioning systems. That is so important, because access to cooling isn't just a matter of comfort. It's health and safety, and it shouldn't be a choice. It shouldn't be up for debate whether people have access to cooling. It's critical. And so, making sure that huge deployment of air conditioners is efficient, is so important. But again, that's not something that you or I can do. That's something that, say in the U.S., that's federal standards that then trickle down to manufacturers and then show up in what options we face when we purchase this equipment ourselves.
It's also a matter of pushing for policies that help break the cycle we're currently facing. As greenhouse gas emissions increase, the number of extreme heat days we see will rise. And it's also the case that the power sector is a large contributor of greenhouse gases. So we're working actively at the state level, at the federal level, at the local level, to try to push for more clean energy every day. This is something that everyone has a say in, right? This is building a grid for the future that we want. And so, it's pushing for these policy choices that send us in that direction.
Colleen: So, I'm kinda jazzed about the grid now. What do you think the best way to bring it up in a conversation, say, you know, I'm having a dinner party and a few friends over without killing the whole, you know, evening?
Julie: That's right. You know, I think there are a heck of a lot of great did-you-knows, but I also worry that my dinner party invitations have been dwindling. It's all about factoring all of those great... There is progress here. I think the challenges are actually really important to talk about, because I think, you know, extreme heat is something that we all feel. And I know that when I'm out walking in this weather, I feel like I'm wilting, right? And yet you go into something like a grocery store and you feel that blast of cold air and it's hard not to think about how much energy that must be using. And you see all these compressors cycling on, cycling off… building after building after building. This is a big challenge and it's something that's increasing.
So how do we tackle that? How do we think about not only do we ensure health and safety, but at the same time, we're bringing more renewables online and we're creating a system that can manage it. So there's some neat things that we haven't talked about in terms of alleviating the pressure that air conditioners put on the system, right? So, for example, rooftop solar is generating the most electricity, the most power during the middle of the day. As more rooftop solar comes online we're actually pushing that peak demand lower and later. That eases the stress on the system. In fact, last year during the July, 2018 heat wave, it was estimated that rooftop solar in New England over the course of about seven days saved on the order of $20 million just in reduced power prices. So we're making progress.
And then we think about these things like these really heavily polluting power plants that are extremely costly that end up trickling through into your power bill. Replacing that with solar and storage with these clean energy solutions, that's exciting stuff. That's clean, that's better, that's more cost effective.
Colleen: Well, Julie, thanks for joining me on the podcast, and I will gladly invite you to dinner at my house anytime to talk about the grid.
Julie: It was a pleasure.
Science FTW: Cynthia DeRocco
Editing and music: Brian Middleton
Research and writing: Jiayu Liang and Pamela Worth
Executive producer: Rich Hayes
Host: Colleen MacDonald