Sea Change Radio

When we think about the transition to renewable energy sources, many of us imagine rooftop solar panels and wind turbine-dotted hills. But it’s not just about capturing energy, it’s also about keeping it. This week on Sea Change Radio we speak with Matt Simon, a Grist senior staff writer, to discuss long-duration energy storage. The transition to renewables for utilities is still very much evolving — efficiency, intermittency, and storage are among the issues scientists have yet to perfect. Simon shares some ideas for how we can build upon existing technologies to store solar and wind power, with longer capacity than lithium-ion batteries, ranging from reservoirs and caverns to our existing fleet of electric vehicles.

Narrator | 00:02 – This is Sea Change Radio covering the shift to sustainability. I’m Alex Wise.

Matt Simon (MS) | 00:23 – We’re actually in this really fascinating time where we are better understanding that the Earth is a resource not for extracting the fossil fuels out of it. That’s stupid and done. We need to stop doing that now. We’re turning more to the energy that is naturally produced by the earth, but also the energy that we can pump underground, for instance, and store down there as a battery. It’s a fascinating frontier.

Narrator | 00:48 – When we think about the transition to renewable energy sources, many of us imagine rooftop solar panels and wind turbine-dotted hills. But it’s not just about capturing energy, it’s also about keeping it. This week on Sea Change Radio we speak with Matt Simon, a Grist senior staff writer, to discuss long-duration energy storage. The transition to renewables for utilities is still very much evolving — efficiency, intermittency, and storage are among the issues scientists have yet to perfect. Simon shares some ideas for how we can build upon existing technologies to store solar and wind power, with longer capacity than lithium-ion batteries, ranging from reservoirs and caverns to our existing fleet of electric vehicles.

Alex Wise (AW) | 01:50 – I’m joined now on Sea Change Radio by Matt Simon. Matt is a senior staff writer at Grist. Matt, welcome to Sea Change Radio.

Matt Simon (MS) | 01:58 – And thank you for having me.

Alex Wise (AW) | 02:00 – It’s good to have you back. You have left wired after a dozen or so years there, and congratulations on joining Grist covering climate. How’s the transition been so far for you?

Matt Simon (MS) | 02:13 – Thanks. Yeah, it’s been fantastic. It’s, um, it’s amazing to be here with a truly phenomenally talented group of people that are laser focused on climate stuff. So I’m, I’m here covering climate solutions, which I feel like, um, is the most optimistic way, um, for my mental health to be approaching climate coverage this day and age. Um, so I’m feeling surprisingly good.

Alex Wise (AW) | 02:37 – I wanted to discuss a piece you’ve written for Grist recently, which delves into long duration energy storage. We often think of just energy storage as battery storage, and that’s a very short-lived type of energy. If you can define long duration energy storage, how the people who run electric grids look at this piece of the puzzle, that would be terrific.

MS | 03:03 – Sure. So the core of the issue here is that as we are deploying more renewables like wind and solar, we need ways to store that energy. So when the wind isn’t blowing or the sun isn’t shining, we need electricity to flow to people’s homes. Um, so the idea here that a lot of people have probably heard about by now is that you have these giant banks of lithium ion batteries on the grid. We have, uh, some of these in California already. They have these also in Texas, wherever you’re seeing the proliferation of renewables, you’re seeing these battery banks pop up. Um, so the idea here is that you, uh, have the sun go down. You’re not generating any solar energy. You draw from those battery banks to give people electricity. Uh, the issue is that even a very large lithium ion battery bank will discharge in about four hours, and that is not nearly long enough to hit you through the nights.

AW | 03:58 – So it’s like a stop gap measure for renewables during like a heat wave or something, let’s say.

MS | 04:03 – Exactly. So it’s, this is, this is short duration energy storage. What we’re now thinking about on a, a bigger scale is long duration energy storage, and these are techniques that store energy for half a day or longer. So one technique that is already in existence, and in fact there’s, there’s over 40 of these in the United States that probably not many people have, have heard about. Um, this is, um, using the, using gravity and water to, to store electricity in this, I guess more specifically, you’re storing energy that you then turn into electricity. So what happens is when there’s a bunch of renewables on the grid, uh, if it’s windy or sunny, you pump water up into a reservoir, and then when that energy disappears, those energy sources disappear during the day. Um, when it’s not windy or at night when it’s not sunny, you let that water flow back down downhill that spins turbines generates electricity. So you’re essentially using the landscape itself as a enormous battery, and you can store a lot of water in these reservoirs and, you know, tap into this energy for half a day or longer. So if, um, you know, it’s a cloudy week, um, for instance, and you’re not generating much solar energy, you’re still generating some, but not nearly as much as if it were a sunny day, um, you can fall back on these long duration energy storage techniques. Um, so it’s, it’s just thinking on two timescales. We’re still going to need a bunch of batteries on the grid to be sure. Um, but this is going to be backup for that backup essentially.

AW | 05:40 – And, and explain the difference between this reservoir source that you’re describing from traditional hydroelectric power.

MS | 05:51 – It’s essentially the same thing. It’s just working two ways. So hydropower, yes, you have a reservoir and you are letting that water loose, uh, by way of gravity turning the turbines to produce electricity. This just reverses that essentially. So it, it sends that water, you pump it uphill once again when you have a lot of renewables on the grid, um, and let it flow back downhill, back and forth and back and forth. It’s, it’s a, an additional layer to traditional hydropower as we think of it.

AW | 06:21 – And it’s, it’s a lot less dependent upon a water source like a, a river or a waterfall, et cetera. And so, like this company, was it Toronto based company, hydro store shoots water up in from caverns, and maybe you can explain it, but they basically create these reservoirs wherever they need to be.

MS | 06:42 – Yeah. What they’re doing is a little bit different from that, that more traditional hydro storage that, that we were talking about. They’re using underground caverns for sort of the same purpose. So what they do is that when, again, there’s renewable energy on the grid, they pump air underground, um, this forces the water in that cavern up to the surface where it pools, and then when you need that energy, that electricity, you let that water flow back underground forces that air back up to a facility where it spins turbines and produces electricity. Slightly different, but it’s actually probably more versatile in the United States because you can cite that more places than, you know, with the hydro stuff. You have to have a reservoir above and a reservoir below. You’re a little bit more restricted in where you can put those but what this this company is doing is probably going to be able to be deployed, uh, much wider in the United States.

AW | 07:38 – Yes, that’s what I was trying to understand is, is can an existing facility utilize their technology? Can you always access caverns if you just go deep enough and then create these reservoirs right at the source? So, uh, close enough to the power plant to use it as a long duration energy storage system?

MS | 08:00 – So these are purpose built facilities for this company. So it’s like you have to build this from scratch, but what you can do is tap into caverns that are either naturally occurring in the ground, um, or have been previously dug out by these, um, these hydrocarbon industries. So the extraction of oil and gas leaves caverns, and they can actually then utilize these now instead for renewable energy, which I think is a, a neat little, a little turn. Um, so yeah, the idea is that you can either use what’s in the ground naturally, what has been dug, or you can also dig your own caves and, uh, you’re again turning the landscape itself into a battery by storing energy in these, these really interesting ways.

AW | 08:46 – How are the various utilities around the country, both private and public, utilizing long duration energy storage systems right now? How are they rolling out? Is it piecemeal or is there some kind of a uniform plan in place?

MS | 09:01 – Because we have so many different utilities in the United States, even so many different utilities within a state like California, this is rolling out piecemeal, um, for that reason that utilities are in charge of, of their own grids. They’re regulated by state regulators, but they, um, but they’re, they’re deploying more renewables and realizing that they need much more storage in order to meet the mandates. Like the state of California says that utilities have to reduce their emissions by x amount by x year. Um, we need a lot of storage for that. So the beauty of this technology is that it isn’t just one long duration energy storage technique that’s gonna win out. So we have these already operating reservoirs, uh, in the United States doing their thing. Hydro store might proliferate across the landscape with those that cavern sort of technique. Uh, but we’re also hearing about, uh, others that might pop up and, and be quite useful. So one is new battery chemistries. So beyond lithium ion, uh, we could develop batteries that just hold that charge much longer than that four hours, um, that lithium io and batteries can do on the grid. We are, um, looking into things like storing energy in concrete, so like heat energy, uh, and then extracting that energy, uh, over time. So it’s, it’s really about thinking of clever ways to move energy around the landscape and then use that energy to produce electricity.

(Music Break) | 10:47

AW | 11:42 – This is Alex Wise on Sea Change Radio, and I’m speaking to Matt Simon, he’s a senior staff writer at Grist. So Matt, talking about these long duration energy storage solutions, you mentioned how lithium ion batteries don’t hold their charge for more than like four hours on an electric grid. Can we ramp up the lithium ion battery to hold that charge longer or do we need to just come up with a different chemistry altogether in terms of a different substrate?

MS | 12:12 – Yeah, there might be ways to tweak lithium ion batteries going forward. I think there, there will be. Um, but those, uh, those alternative chemistries I think are going to be quite promising. Just finding, I mean, a battery in a sense, but we’re using different sorts of materials in that battery to hold that charge for longer. So yeah, that four hours, I mean, just think about if the power went out entirely, how many homes and businesses you need to electrify, um, with, with those batteries, it is just, it’s not going to last more than four hours. So we are now also thinking about ways to distribute batteries, uh, smaller batteries across the landscape. So vehicle to grid technology is super fascinating. So a lot of electric vehicles these days are coming out with an additional technology built in called, uh, V two G vehicle to grid. They not only take power from the grid when they’re charging, they can discharge their power back into the grid in times of need. So what is developing is you have any number of electric vehicles sitting idle in garages across the landscape when a utility needs more power. So that’s typically at the end of the day when, when demand spikes, people come home, they switch on their appliances all at once, um, it needs to provide that power. It can’t do that with solar power if the sun is simultaneously going down. So what we’re going to have here is energy stored, again, in so many fascinating ways across the landscape. It’s going to be in the earth itself with these long duration energy storage techniques, but also your electric vehicle will be backup power for the grid and any number of other vehicles. Large trucks, for instance, when they finish their days, they go park in a lot, they can discharge that remaining juice back into the grid. There is a school district in Oakland that is doing this with school buses. I report on this a number of months back where they, um, drive kids to school. Um, they plug back into the grid and charge when there’s not as much demand on the grid. They take those kids back home and then plug in at the end of the day, but instead of charging again, they have additional juice left in those, those buses. They discharge that energy, that additional energy back into the grid again at this time when people are returning home and switching on appliances. So looking at the grid of the future, it’s not the rigid sort of burn fossil fuels whenever we need energy, um, and get along fine, but destroy the planet by way of carbon emissions along the way. It’s this much more flexible grid where we as consumers are actually active participants, um, where we’re sending energy back into the grid as needed. Also, think about the proliferation of, of home batteries. So these much larger batteries than you’d find in an electric vehicle, those will be tapped into as well, um, by the grid operator, the utility. So it’s again, much more flexibility that we need in order to accommodate the intermittent nature of renewable energy.

AW | 15:20 – Listening to what you’re describing about vehicles, one of the holy grails will be to decrease the time that it takes to recharge vehicles. So let’s say a school bus has an enormous, an electric school bus has an enormous battery, and you discharge that into the grid, you want to make sure that that school bus can operate the next morning, but if it only takes 15 minutes to give it a full charge, that solves a lot of problems, right?

MS | 15:45 – Yeah. And just think of the enormous size of a school bus battery. You need a very large battery in there. So at the end of the day when they’re dropping those kids off, they inevitably have additional juice that they don’t need, right? The kids are home and safe. The school bus can plug back into the grid and serve as an asset for the utility operator.

AW | 16:08 – And right now, that could be on the weekend when they’re not using it at all. But you want to avoid delays to the transportation system as well, of course.

MS | 16:17 – Exactly. Yeah. So they will sit idle on holidays, weekends, summer when kids aren’t in school. Um, this will be a giant battery, um, disguised as a school bus <laugh> basically and then thinking about the, just the extreme diversity of different kinds of vehicles. So, things that are on different schedules, city vehicles that will be electrified. Um, they operate on a more or less set schedule. The cars that we drive as regular consumers are kind of willy-nilly. They’re all over the place, but we charge them in at different times of day. You might plug it in at work, maybe, um, you’ll charge up fully at work during the day when there’s a lot of solar energy on the grid, drive home and only, uh, drain away a fraction of that battery. And then, uh, when you plug in in the garage, you can give that plentiful energy back to the grid. It’s this really interesting dance, the sort of coordination between all these different batteries across the landscape, um, be they in electric vehicles or in the ground itself.

AW | 17:24 – And have there been some encouraging breakthroughs in terms of the time it takes to recharge vehicle batteries?

MS | 17:33 – Yeah, that’s getting better. And that’s the beauty of, of any technology is that this is going to not only get better and more efficient with time, it’s going to get cheaper with time. We have operated for centuries now on fossil fuels that are, uh, a fuel that you cannot improve upon, right? You, you pull it outta the ground, you burn it, it might get more efficient, burning it in, in automobiles over time. It’s still a basic fuel out of the earth. Um, with batteries they will get, um, they’ll get, will get faster recharging. We already have that in in phones, right? They used to charge a lot, uh, slower than they do now. Um, we’ll need that in cars, um, especially to encourage adoption. Like I think a lot of people are still worried about getting stuck somewhere and, and, uh, having to sit with a car in a out, out there station, uh, for several hours for your battery to recharge, that’ll help with the range anxiety, I think.

AW | 18:34 – Yeah, these, these level three chargers that have proliferated, we first saw the Tesla Supercharging network. That’s one of the reasons why Teslas have been so popular is because they’ve been able to kind of combat that range anxiety you’re speaking about.

MS | 18:50 -Exactly. And I just really want to reiterate that these technologies, all of them are going to get better and cheaper with time. That includes things like heat pumps that are a replacement for gas furnaces. They’re extremely efficient already at extracting warmth from even frigid outdoor air and pumping it inside. Um, that’s gonna be essential for decarbonization. Um, uh, electric vehicles will get cheaper over time and more efficient. Um, all of these renewable green technologies are only getting better from here, whereas fossil fuels are stagnation through and through.

(Music Break) | 19:40

AW | 20:05 – This is Alex Wise on Sea Change Radio, and I’m speaking to Matt Simon. He’s a senior staff writer at Grist. So Matt, getting back to the grid side of things, we heard for many years as utilities started to ramp up their portfolio into containing more renewables, that natural gas or fossil gas would be the bridge fuel to allow intermittency to not be such an issue that we wouldn’t have these rolling blackouts as, as long as we can have natural gas be the backup. Have we seen a, a change in terms of natural gas being a, a piece of the grid operator’s puzzle?

MS | 20:45 – It still is. Yeah. We still need it in every state grid in the United States now because we have this intermittency issue with renewables. So yes, as you say, whenever that sun is down and the wind isn’t blowing, you need to spin up natural gas power plants to produce that energy because a grid is a very tricky thing. You have to keep it at a very steady pace to constantly meet waning and waxing demand on that grid or else the whole thing collapses. So you need that natural gas backup. So the idea here is yes, with with these batteries, we can reduce our dependence on that natural gas. It used to be that we burn coal to, to make up for the, the shortfalls that of renewable, uh, energy that has switched to, uh, natural gas, which is it burns cleaner, I guess. Yeah, true. But it’s still a natural gas still takes a lot of energy to pull it out of the earth. It takes a lot of energy to, to turn it into something that we can burn in a power plant. Of course, you have the emissions involved with, with burning that there, um, we cannot rely on that going forward if we want to truly reduce our emissions. And that’s where this distributed network of batteries is really going to help. It’s only gonna get better from here. We’re going to use less and less natural gas, uh, going forward. The tricky thing is that with decarbonization and electrification, we’re not gonna be using a less electricity going forward. We’re actually gonna be using a lot more. So the grid really needs to keep up here as it transitions to renewables. And the way to do that is with these batteries.

AW | 22:27 – The question I really wanted to ask is, these reservoirs that you’re talking about, these long duration energy storage solutions in the near term, are they replacing batteries as the safety valve for the grids, or are they replacing natural gas in their portfolio?

MS | 22:43 – They would be working in concert with traditional batteries as we know them. So it wouldn’t be either or. So you’d have, we still have those lithium ion battery banks to make up for that four hours, um, of, of, of backup energy. But beyond that, we need these longer duration energy storage. So once that four hours runs out, you switch over to the reservoir producing, um, electricity by spinning those, those turbines. Um, and so yeah, at the moment we do need to still, we don’t have enough of this on the grid as it is. We are, you know, the, the, uh, department of Energy has put out lots of money for people to develop more of these long duration energy storage systems because it’s not going to be just reservoirs. It’s not going to be just what hydro store is doing. Um, in those subterranean areas, it’s going to be all kinds of these different technologies working in concerts. Some of them are not fully developed, they’re still in the research phase. Um, but the, the grid operators, scientists, uh, private companies understand the urgency here that we have to stop burning natural gas in, in power plants as backup. There are ways to do this with storing energy, um, in a cleaner way on the landscape and in traditional lithium-ion batteries.

AW | 23:57 – And, and looking beyond North America, are there some examples of grids in extreme cold or extreme heat utilizing innovative solutions beyond just batteries? I’m thinking in let’s say Iceland or Greenland. Can they tap into geothermal as a backup for their grid?

MS | 24:21 -Sure, yeah. I mean, it’s great that you bring up geothermal because that is a massive resource. So, um, yes, in those, uh, Nordic countries, they use a good amount. They just have the geology required. So, basically what you’re doing is you’re tapping into the inherent very hot temperatures of the, the earth to produce electricity. This is actually a, a kind of a fascinating, um, uh, offshoot of this is not producing electricity with that geothermal energy. But increasingly in the United States and, and really elsewhere around the world, um, we are extracting heat from that. So you can have in, uh, there’s a, there’s a, a utility in Massachusetts that’s actually deploying this in a neighborhood. They drill down not nearly as far as you need to go to produce, like to get the heat to produce electricity from geothermal. They drill down and they pump water through, and the, it’s about 55 degrees, um, that the earth is a consistent temperature throughout the year. You feed that water up to the surface and it runs around the neighborhood like a natural gas pipeline would, except it’s water pipe from the earth that flows into heat pumps. And the heat pumps extract either heat or cool from that water. And you can then, instead of running a, um, a neighborhood on natural gas, uh, uh, heating, you do it instead with the, the actual heat of the earth, which is, which is really interesting. So yes, we can actually tap into the earth itself, both for that geothermal energy as backup power on the grid when it is needed. But also as we’re decarbonizing homes getting rid of natural gas, we need to use the earth as well to tap into that consistent 55 degrees, um, throughout the year and, and, uh, flow that through heat pumps.

AW | 26:10 – And is that technology that you’re referring to in Massachusetts, is that a form of geothermal technology or is that something different?

MS | 26:17 – Yep, it’s geothermal. It’s called networked geothermal. So they are, this utility is part of a consortium of, um, different utilities across the United States that have formed this basically fact-finding group and information sharing group, uh, that represents about half of the utility customers in the United States. They’re saying, well shoot, if we’re required by our states to meet certain emissions targets, uh, why would we install new natural gas in a, like a new subdivision or whatever the case may be? Why not put in these, these geothermal network geothermal, um, systems that, uh, you basically, you actually, you do use the same piping as you do for natural gas, it’s just water flowing through it instead, are there also ways in existing neighborhoods that if you get everybody in the neighborhood to sign up for this, can we swap out natural gas, um, and put in, in this water pipe from deepen the earth? It’s a little expensive to do this still, but again, with these technologies, you are going to only see improvements both in the price and in the efficiency. So get ready to hear more about network geothermal to be sure. But, uh, we’re in this really fascinating time where we are better understanding that the Earth is a resource not for extracting the fossil fuels out of it. That’s stupid and done. We need to stop doing that now. We’re turning more to the energy that is naturally produced by the earth, but also the energy that we can pump underground, for instance, and store down there as a battery’s. It’s a fascinating frontier.

AW | 27:56 – Matt Simon from Grist. Thanks so much for being my guest on Sea Change Radio.

MS | 28:01 – Thank you for having me.

Narrator | 28:16 – You’ve been listening to Sea Change Radio. Our intro music is by Sanford Lewis. And our outro music is by Alex Wise – additional music by Freddie Hubbard, the Red Hot Chili Peppers and James Brown. Check out our website at SeaChangeRadio.com to stream or download the show or subscribe to our podcast. Visit our archives there to hear from Bill McKibben, Van Jones, Paul Hawken, and many others. And tune into Sea Change Radio next week as we continue making connections for sustainability. For Sea Change Radio, I’m Alex Wise.